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1.  Do weight perceptions among obese adults in Great Britain match clinical definitions? Analysis of cross-sectional surveys from 2007 and 2012 
BMJ Open  2014;4(11):e005561.
To assess the proportion of the adult obese population in Great Britain who would describe their weight using the terms ‘obese’ and ‘very overweight’ in 2007 and 2012, and identify factors associated with more accurate weight perceptions.
Analysis of weight perception data from two population-based surveys.
Population surveys conducted in Great Britain.
Survey respondents (N=657) whose self-reported weight and height placed them in the obese category: body mass index (BMI) ≥30.
Primary outcome measure
Self-identification using the terms ‘obese’ and ‘very overweight’.
The proportion of obese adults selecting the term ‘obese’ to describe their body size was very low in both women (13% in 2007 and 11% in 2012) and men (4% in 2007 and 7% in 2012) and did not change significantly. Recognition of a substantial degree of overweight (as indexed by endorsement of either of the terms ‘obese’ or ‘very overweight’) declined substantially in women, from 50% in 2007 to 34% in 2012. It was not significantly changed in men (27% in 2007 and 23% in 2012). Having a higher BMI, and being able to identify the BMI threshold for obesity were associated with self-identifying as obese or very overweight.
The majority of the adult obese population of Great Britain do not identify themselves as either ‘obese’ or even ‘very overweight’. Public health initiatives to tackle obesity are likely to be hampered by this lack of recognition of weight status. It is important to understand whether moves to increase personal awareness of weight status in the obese population can facilitate beneficial behaviour change, and what role health professionals can play in increasing awareness of weight status in obese patients.
PMCID: PMC4248082  PMID: 25394816
2.  The change in weight perception of weight status among the overweight: comparison of NHANES III (1988–1994) and 1999–2004 NHANES 
This study seeks to determine whether perception of weight status among the overweight has changed with the increasing overweight/obesity prevalence.
The perception of weight status was compared between overweight participants (BMI between 25.0–29.9 kg/m2) from NHANES III (1988–1994) and overweight participants from NHANES 1999–2004. Perception of weight status was assessed by asking participants to classify their weight as about the right weight, underweight or overweight. Comparisons were made across age groups, genders, race/ethnicities and various income levels.
Fewer overweight people during the NHANES 1999–2004 survey perceived themselves as overweight when compared to overweight people during the NHANES III survey. The change in distortion between the survey periods was greatest among persons with lower income, males and African-Americans.
The increase in overweight/obesity between the survey years (NHANES III and NHANES 1999–2004 has been accompanied with fewer overweight people perceiving themselves as overweight.
PMCID: PMC2275297  PMID: 18269748
3.  Underestimation of weight and its associated factors among overweight and obese adults in Pakistan: a cross sectional study 
BMC Public Health  2011;11:363.
Weight loss is known to decrease the health risks associated with being overweight and obese. Awareness of overweight status is an important determinant of weight loss attempts and may have more of an impact on one's decision to lose weight than objective weight status. We therefore investigated the perception of weight among adults attending primary care clinics in Karachi, Pakistan, and compared it to their weight categories based on BMI (Body Mass Index), focusing on the underestimation of weight in overweight and obese individuals. We also explored the factors associated with underestimation of weight in these individuals.
This was a cross sectional study conducted on 493 adults presenting to the three primary care clinics affiliated with a tertiary care hospital in Karachi, Pakistan. We conducted face to face interviews to gather data on a pre-coded questionnaire. The questionnaire included detail on demographics, presence of comorbid conditions, and questions regarding weight assessment. We measured height and weight of the participants and calculated the BMI. The BMI was categorized into normal weight, overweight and obese based on the revised definitions for Asian populations. Perception about weight was determined by asking the study participants the following question: Do you consider yourself to be a) thin b) just right c) overweight d) obese. We compared the responses with the categorized BMI. To identify factors associated with underestimation of weight, we used simple and multiple logistic regression to calculate crude odds Ratios (OR) and adjusted Odds Ratios (AOR) with 95% Confidence Intervals.
Overall 45.8% (n = 226) of the study participants were obese and 18% (n = 89) were overweight. There was poor agreement between self perception and actual BMI (Kappa = 0.24, SE = 0.027, p < 0.001). Among obese participants a large proportion (73%) did not perceive themselves as obese, although half (n = 102) of them thought they may be overweight. Among the overweight participants, half (n = 41) of them didn't recognize themselves as overweight. Factors associated with misperception of weight in overweight and obese participants were age ≥ 40 years (AOR = 3.4; 95% CI: 1.8-6.4), male gender (AOR = 2.97; 95% CI: 1.6-5.5), being happy with ones' weight (AOR = 6.4; 95% CI: 3.4-12.1), and not knowing one's ideal weight (AOR = 2.45, 95% CI: 1.10-5.47).
In this cross sectional survey, we observed marked discordance between the actual and perceived weight. Underestimation of individual weight was more common in older participants (≥ 40 years), men, participants happy with their weight and participants not aware of their ideal weight. Accurate perception of one's actual weight is critical for individuals to be receptive to public health messages about weight maintenance or weight loss goals. Therefore educating people about their correct weight, healthy weights and prevention of weight gain are important steps towards addressing the issue of obesity in Pakistan.
PMCID: PMC3115862  PMID: 21605350
4.  Satisfied or unaware? Racial differences in perceived weight status 
Obesity is disproportionately prevalent among many racial/ethnic minority communities. The efficacy of weight control efforts in these groups may depend on individual's ability to accurately perceive their weight status. We examined whether racial/ethnic differences exist in weight status misperception among overweight adults.
Nationally-representative data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002 were examined. Participants included overweight and obese adult men (n = 3115) and women (n = 3437). Weight status misperception was identified among respondents who self-reported being "about the right weight/underweight."
Blacks (OR = 2.06, 95% CI: 1.71, 2.54) were twice as likely and Hispanics (OR = 1.70, 95%CI: 1.33, 2.17) were 70-percent more likely than Whites to misperceive their weight, in models adjusted for age, education, income, marital status, self-reported health, and self-reported medical diagnosis of overweight. Black overweight (OR = 2.03, 95% CI: 1.26, 3.26) and obese (OR = 3.56, 95% CI: 1.57, 8.11) women were considerably more likely to exhibit misperception compared to their White female counterparts. Odds of misperception were higher among overweight Black (OR = 2.20, 95%CI: 1.54, 3.15), Hispanic (OR = 1.89, 95% CI: 1.30, 2.75), and obese Black men (OR = 2.84, 95% CI: 1.54, 5.22), compared to White men.
Weight status misperceptions among the overweight are more common among Blacks, and Hispanic men. The persistence of racial/ethnic differences after adjustment for medical diagnosis of overweight may suggest some resistance to physician weight counseling. Identifying strategies to correct weight status misperceptions status may be necessary to ensure the efficacy of clinical and public health obesity interventions conducted among these groups.
PMCID: PMC1684255  PMID: 17096859
5.  The Double Burden of Obesity and Malnutrition in a Protracted Emergency Setting: A Cross-Sectional Study of Western Sahara Refugees 
PLoS Medicine  2012;9(10):e1001320.
Surveying women and children from refugee camps in Algeria, Carlos Grijalva-Eternod and colleagues find high rates of obesity among women as well as many undernourished children, and that almost a quarter of households are affected by both undernutrition and obesity.
Households from vulnerable groups experiencing epidemiological transitions are known to be affected concomitantly by under-nutrition and obesity. Yet, it is unknown to what extent this double burden affects refugee populations dependent on food assistance. We assessed the double burden of malnutrition among Western Sahara refugees living in a protracted emergency.
Methods and Findings
We implemented a stratified nutrition survey in October–November 2010 in the four Western Sahara refugee camps in Algeria. We sampled 2,005 households, collecting anthropometric measurements (weight, height, and waist circumference) in 1,608 children (6–59 mo) and 1,781 women (15–49 y). We estimated the prevalence of global acute malnutrition (GAM), stunting, underweight, and overweight in children; and stunting, underweight, overweight, and central obesity in women. To assess the burden of malnutrition within households, households were first classified according to the presence of each type of malnutrition. Households were then classified as undernourished, overweight, or affected by the double burden if they presented members with under-nutrition, overweight, or both, respectively.
The prevalence of GAM in children was 9.1%, 29.1% were stunted, 18.6% were underweight, and 2.4% were overweight; among the women, 14.8% were stunted, 53.7% were overweight or obese, and 71.4% had central obesity. Central obesity (47.2%) and overweight (38.8%) in women affected a higher proportion of households than did GAM (7.0%), stunting (19.5%), or underweight (13.3%) in children. Overall, households classified as overweight (31.5%) were most common, followed by undernourished (25.8%), and then double burden–affected (24.7%).
The double burden of obesity and under-nutrition is highly prevalent in households among Western Sahara refugees. The results highlight the need to focus more attention on non-communicable diseases in this population and balance obesity prevention and management with interventions to tackle under-nutrition.
Please see later in the article for the Editors' Summary
Editors' Summary
Good nutrition is essential for human health and survival. Insufficient food intake causes under-nutrition, which increases susceptibility to infections; intake of too much or inappropriate food, in particular in interaction with sedentary behaviour, can lead to obesity, which increases the risk of non-communicable diseases such as diabetes. During the past 30 years, the prevalence (the proportion of a population affected by a condition) of obesity has greatly increased, initially among adults in industrialized countries, but more recently among children and in less-affluent populations. Now, worldwide, overweight people outnumber under-nourished people. Furthermore, some populations are affected by both under-nutrition and obesity, forms of malnutrition that occur when the diet is suboptimal for health. So, for example, a child can be both stunted (short for his or her age, an indicator of long-term under-nutrition) and overweight (too heavy for his or her age). The emergence of this double burden of malnutrition has been attributed to the nutrition transition—the rapid move because of migration or urbanization to a lifestyle characterized by low levels of physical activity and high consumption of refined, energy-dense foods—without complete elimination of under-nutrition.
Why Was This Study Done?
Refugees are one group of people in whom under-nutrition and obesity sometimes coexist. Worldwide, in 2010, 15.4 million refugees were dependent on host governments and international humanitarian agencies for their food security and well-being. It is essential that these governments and organizations provide appropriate food assistance programs to refugees—policies that are appropriate during acute emergencies may not be appropriate in protracted emergencies and may contribute to the emergence of the double burden of malnutrition among refugees. Unfortunately, the extent to which the double burden of malnutrition affects refugees in protracted emergencies is unknown. In this cross-sectional study (an investigation that looks at the characteristics of a population at a single time), the researchers assessed the double burden of malnutrition among people from Western Sahara who have been living in four refugee camps near Tindouf city, Algeria, since 1975.
What Did the Researchers Do and Find?
The researchers used data from a 2010 survey that measured the height and weight of children and the height, weight, and waist circumference of women living in 2,005 households in the Algerian refugee camps. For the children, they estimated the prevalence of global acute malnutrition (which includes thin, “wasted” children, as indicated by a low weight for height based on the World Health Organization growth standards, and those with nutritional oedema), stunting, and underweight and overweight (low and high weight for age and gender, respectively). For the women, they estimated the prevalence of stunting, underweight (body mass index less than 18.5 kg/m2), overweight (body mass index greater than 25 kg/m2), and central obesity (a waist circumference of more than 80 cm). Among the children, 9.1% had global acute malnutrition, 29.1% were stunted, 8.6% were underweight, and 2.4% were overweight. Among the women, 14.8% were stunted, 53.7% were overweight, and 71.4% had central obesity. Notably, central obesity and overweight in women affected more households than global acute malnutrition, stunting, and underweight in children. Finally, based on whether a household included members with under-nutrition or overweight, alone or in combination, the researchers classified a third of households as overweight, a quarter as undernourished, and a quarter as affected by the double burden of malnutrition.
What Do These Findings Mean?
These findings indicate that there is a high prevalence of the double burden of malnutrition among households in Western Saharan refugee camps in Algeria. Although this study provides no information on men and does not investigate whether the obesity seen in these camps leads to an increased risk of diabetes and other non-communicable diseases, these findings have several important implications for the provision of food assistance and care for protracted humanitarian emergencies. For example, they highlight the need to promote long-term food security and to improve nutrition adequacy and food diversity in protracted emergencies. In addition, they suggest that current food assistance programs that are suitable for acute emergencies may not be suitable for extended emergencies. They also highlight the need to focus more attention on non-communicable diseases in refugee camps and to develop innovative ways to provide obesity prevention and management in these settings. However, as the researchers stress, careful policy and advocacy work is essential to ensure that efforts to deal with the threat of obesity among refugees do not jeopardize support for life-saving food assistance programs for refugees.
Additional Information
Please access these websites via the online version of this summary at
Wikipedia provides background information about the Western Sahara refugee camps near Tindouf, Algeria (note that Wikipedia is a free online encyclopedia that anyone can edit)
The World Health Organization provides information on all aspects of nutrition and obesity (in several languages)
The United Nations World Food Programme is the world's largest humanitarian agency fighting hunger worldwide; its website provides detailed information about hunger and information about its work in the Western Sahara refugee camps in Algeria, including personal stories and photographs of food distribution
The United Nations High Commissioner for Refugees is the United Nations body mandated to lead and coordinate international action to protect refugees and resolve refugee problems worldwide; its website provides detailed information about its work in the Western Sahara refugee camps in Algeria
Oxfam also provides detailed information about its work in the Algerian refugee camps, a description of the camps, and personal stories from people living in the camps
An article published by the Food and Agriculture Organization of the United Nations explains the double burden of malnutrition
PMCID: PMC3462761  PMID: 23055833
6.  Obesity, Overweight, and Perceptions about Body Weight among Middle-Aged Adults in Dar es Salaam, Tanzania 
ISRN Obesity  2012;2012:368520.
Background. Prevalence of obesity is increasing throughout the world at an alarming rate. Appropriate perception of one's own body weight is important for improved weight control behavior. This study was conducted to determine the prevalence of overweight and obesity and assess perception of body weight among middle aged adults in Dar es Salaam, Tanzania. Methods. Structured questionnaire was used to collect sociodemographic and lifestyle information including perception about body weight. Anthropometric measurements were taken by a trained person following standard procedures. Results. Prevalence of obesity was 13% and 36% among men and women, respectively. There was significant gender difference in perception of body weight (12% and 25% of men and women perceived their body weight as overweight). Only 2% of women perceived themselves as obese whereas none of the men did so. Among overweight men, only 22% perceived themselves as overweight/obese compared to 38% of overweight women who perceived themselves as overweight/obese. Overall, majority of the participants (87%) were willing to lose weight. Conclusions. There is a great difference between perceived and actual body weight with men underestimating their body weight more than women. Educational programs regarding overweight and obesity and the associated health consequences are highly recommended in Tanzania.
PMCID: PMC3914263  PMID: 24527261
7.  Prevalence, risk factors, and uptake of interventions for sexually transmitted infections in Britain: findings from the National Surveys of Sexual Attitudes and Lifestyles (Natsal) 
Lancet  2013;382(9907):1795-1806.
Population-based estimates of prevalence, risk distribution, and intervention uptake inform delivery of control programmes for sexually transmitted infections (STIs). We undertook the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) after implementation of national sexual health strategies, and describe the epidemiology of four STIs in Britain (England, Scotland, and Wales) and the uptake of interventions.
Between Sept 6, 2010 and Aug 31, 2012, we did a probability sample survey of 15 162 women and men aged 16–74 years in Britain. Participants were interviewed with computer-assisted face-to-face and self-completion questionnaires. Urine from a sample of participants aged 16–44 years who reported at least one sexual partner over the lifetime was tested for the presence of Chlamydia trachomatis, type-specific human papillomavirus (HPV), Neisseria gonorrhoeae, and HIV antibody. We describe age-specific and sex-specific prevalences of infection and intervention uptake, in relation to demographic and behavioural factors, and explore changes since Natsal-1 (1990–91) and Natsal-2 (1999–2001).
Of 8047 eligible participants invited to provide a urine sample, 4828 (60%) agreed. We excluded 278 samples, leaving 4550 (94%) participants with STI test results. Chlamydia prevalence was 1·5% (95% CI 1·1–2·0) in women and 1·1% (0·7–1·6) in men. Prevalences in individuals aged 16–24 years were 3·1% (2·2–4·3) in women and 2·3% (1·5–3·4) in men. Area-level deprivation and higher numbers of partners, especially without use of condoms, were risk factors. However, 60·4% (45·5–73·7) of chlamydia in women and 43·3% (25·9–62·5) in men was in individuals who had had one partner in the past year. Among sexually active 16–24-year-olds, 54·2% (51·4–56·9) of women and 34·6% (31·8–37·4) of men reported testing for chlamydia in the past year, with testing higher in those with more partners. High-risk HPV was detected in 15·9% (14·4–17·5) of women, similar to in Natsal-2. Coverage of HPV catch-up vaccination was 61·5% (58·2–64·7). Prevalence of HPV types 16 and 18 in women aged 18–20 years was lower in Natsal-3 than Natsal-2 (5·8% [3·9–8·6] vs 11·3% [6·8–18·2]; age-adjusted odds ratio 0·44 [0·21–0·94]). Gonorrhoea (<0·1% prevalence in women and men) and HIV (0·1% prevalence in women and 0·2% in men) were uncommon and restricted to participants with recognised high-risk factors. Since Natsal-2, substantial increases were noted in attendance at sexual health clinics (from 6·7% to 21·4% in women and from 7·7% to 19·6% in men) and HIV testing (from 8·7% to 27·6% in women and from 9·2% to 16·9% in men) in the past 5 years.
STIs were distributed heterogeneously, requiring general and infection-specific interventions. Increases in testing and attendance at sexual health clinics, especially in people at highest risk, are encouraging. However, STIs persist both in individuals accessing and those not accessing services. Our findings provide empirical evidence to inform future sexual health interventions and services.
Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and the Department of Health.
PMCID: PMC3899025  PMID: 24286785
8.  Factors Associated with Misperception of Weight in the Stroke Belt 
Understanding the reasons for overweight and obesity is critical to addressing the obesity epidemic. Often the decision to lose weight is based as much on one’s self-perception of being overweight as on inherent health benefits.
Examine the relationships between self-reported health and demographic factors and measured health risk status and the misperception of actual weight status.
Cross-sectional study of factors associated with self-perceived overweight status in participants who self-selected to participate in stroke risk factor screenings. Participants were asked, “Are you overweight?” before their body mass index (BMI) was determined from measured weight and self-reported height. Demographics including, sex, race, education, and location; and health status variables including level of exercise and history of high blood pressure and cholesterol were collected.
Mean BMI for the group was 30 kg/m2. Most women (53.1%) perceived themselves to be overweight, whereas most men (59.6%) perceived themselves not to be overweight. Factors related to misperception of weight status varied by actual BMI category. Among individuals with normal BMI, sedentary individuals had 63% higher odds of misperceiving themselves as overweight. Sedentary individuals with obese BMI were at 55% reduced odds of misperceiving themselves as normal weight.
Active obese and overweight individuals may be more likely to incorrectly perceive themselves as normal weight, and thus misperceive their risk for stroke. Thus, it is not enough to only counsel individuals to be active. Physicians and other health professionals need to counsel their clients to both be active and to attain and maintain a healthy weight.
PMCID: PMC2359477  PMID: 18196349
obesity; weight perception; body mass index; stroke belt; physical activity
9.  Does perception equal reality? Weight misperception in relation to weight-related attitudes and behaviors among overweight and obese US adults 
Weight misperception might preclude the adoption of healthful weight-related attitudes and behaviors among overweight and obese individuals, yet limited research exists in this area. We examined associations between weight misperception and several weight-related attitudes and behaviors among a nationally representative sample of overweight and obese US adults.
Data from the 2003-2006 National Health and Nutrition Examination Survey (NHANES) were used. Analyses included non-pregnant, overweight and obese (measured body mass index ≥ 25) adults aged 20 and older. Weight misperception was identified among those who reported themselves as "underweight" or "about the right weight". Outcome variables and sample sizes were: weight-loss attitudes/behaviors (wanting to weigh less and having tried to lose weight; n = 4,784); dietary intake (total energy intake; n = 4,894); and physical activity (meets 2008 US physical activity recommendations, insufficiently active, and sedentary; n = 5,401). Multivariable regression models were stratified by gender and race/ethnicity. Analyses were conducted in 2009-2010.
These overweight/obese men and women who misperceived their weight were 71% (RR 0.29, 95% CI 0.25-0.34) and 65% (RR 0.35, 95% CI 0.29-0.42) less likely to report that they want to lose weight and 60% (RR 0.40, 95% CI 0.30-0.52) and 56% (RR 0.44, 95% CI 0.32-0.59) less likely to have tried to lose weight within the past year, respectively, compared to those who accurately perceived themselves as overweight. Blacks were particularly less likely to have tried to lose weight. Weight misperception was not a significant predictor of total energy intake among most subgroups, but was associated with lower total energy intake among Hispanic women (change -252.72, 95% CI -433.25, -72.18). Men who misperceived their weight were less likely (RR 0.68, 95% CI 0.52-0.89) to be insufficiently active (the strongest results were among Black men) and women who misperceived their weight were less likely (RR 0.74, 95% CI 0.54, 1.00, p = 0.047) to meet activity recommendations compared to being sedentary.
Overall, weight misperception among overweight and obese adults was associated with less likelihood of interest in or attempts at weight loss and less physical activity. These associations varied by gender and race/ethnicity. This study highlights the importance of focusing on inaccurate weight perceptions in targeted weight loss efforts.
PMCID: PMC3073863  PMID: 21426567
10.  Accuracy of Child and Adolescent Weight Perceptions and Their Relationships to Dieting and Exercise Behaviors: NHANES 
Academic pediatrics  2013;13(4):371-378.
Recent public health and media attention on child obesity may have altered accuracy of self-perception of obesity and associated weight control behaviors in children and adolescents. Thus, we examined whether accuracy of weight perceptions were associated with weight loss behaviors.
Study design
We examined children 8–15 year olds in the National Health and Nutrition Examination Survey (2005–2010) who reported themselves as: “overweight/too fat,” “about right,” or “underweight/too thin.” Children reported on efforts to lose weight and engagement in specific weight control behaviors, including how frequently he/she had “been on a diet, starved, cut back on eating, skipped meals, or exercised” to lose weight. We categorized obesity based on measured BMI, and determined accuracy of weight perceptions. We used chi-squared tests to examine age- and sex-based differences in accuracy of perceptions and relationship to weight loss behaviors.
Girls and older children more accurately perceived weight status. Both girls and boys of all ages who perceived themselves as overweight were more likely to engage in weight loss behaviors. Children who were overweight engaged in more weight loss behaviors than healthy weight children perceiving themselves as overweight. Among children who reported themselves as “about right,” overweight children engaged in more weight loss behaviors than healthy weight children but less so than those who accurately perceived being overweight.
The perception of being overweight and actual overweight status are both strongly associated with weight loss behaviors. These findings have important implications for counseling patients who may have inaccurate weight perceptions.
PMCID: PMC4130653  PMID: 23830022
weight perceptions; obesity; weight control behaviors; sex differences
11.  Where do young men want to access STI screening? A stratified random probability sample survey of young men in Great Britain 
Sexually Transmitted Infections  2012;88(6):427-432.
Rates of sexually transmitted infections (STIs) in UK young people remain high in men and women. However, the National Chlamydia Screening Programme has had limited success in reaching men. The authors explored the acceptability of various medical, recreational and sports venues as settings to access self-collected testing kits for STIs and HIV among men in the general population and those who participate in sport.
A stratified random probability survey of 411 (weighted n=632) men in Great Britain aged 18–35 years using computer-assisted personal and self-interviews.
Young men engaged well with healthcare with 93.5% registered with, and 75.3% having seen, a general practitioner in the last year. 28.7% and 19.8% had previously screened for STIs and HIV, respectively. Willingness to access self-collected tests for STIs (85.1%) and HIV (86.9%) was high. The most acceptable pick-up points for testing kits were general practice 79.9%, GUM 66.8% and pharmacy 65.4%. There was a low acceptability of sport venues as pick-up points in men as a whole (11.7%), but this was greater among those who participated in sport (53.9%).
Healthcare settings were the most acceptable places for accessing STI and HIV self-testing kits. Although young men frequently access general practice, currently little STI screening occurs in this setting. There is considerable potential to screen large numbers of men and find high rates of infection through screening in general practice. While non-clinical settings are acceptable to a minority of men, more research is needed to understand how these venues could be used most effectively.
PMCID: PMC3461759  PMID: 22510331
Chlamydia trachomatis; HIV; men; patients-views; sports; testing; sexual practices; sexual behaviour; risk behaviours; heterosexuals; sexual health; sociology; opportunistic inf.; heterosexual behaviour; social/policy perspectives; behavioural intervention; AIDS; gum services; risk profiles; service development
12.  Exploring the Relationship between Weight, Race and Sexual Behaviors among Girls 
Pediatrics  2009;124(5):e913-e920.
The relationship between weight and sexual behavior among adolescents is poorly understood. In this descriptive study, we examined the relationship between three weight indices and six sexual behaviors in a nationally representative sample of high school girls.
Patients and Methods
We performed a cross-sectional analysis of self-reported data from 7,193 high school girls who completed the 2005 Youth Risk Behavior Surveillance survey. We used multivariate logistic regression to examine associations among three weight indices (body mass index (BMI) calculated from self-reported weight and height, perceived weight and weight misperception) and six sexual behaviors (ever had vaginal sex, sex before age 13, ≥ 4 sexual partners, and alcohol, condom and oral contraceptive use at last sex) adjusting for age, race/ethnicity and a history of intimate partner violence.
Most participants were Caucasian (62%), had a normal BMI (69%) and perceived their weight as ‘about right’ (51%). Almost half (49%) reported ever having sex. In the regression analysis, there were no differences in the likelihood of ever having sex based on BMI or weight perception accuracy; however, girls who perceived themselves as overweight were less likely to have ever had sex. Among sexually-active girls, those with low BMI, who perceived themselves as overweight or with overweight misperceptions were less likely to report condom use at last sex. Sexually active girls who perceived themselves as overweight were also more likely to have had sex before age 13. Associations between the three weight indices and sexual risk behaviors varied across racial/ethnic groups.
Sexual risk behaviors may be more common among girls who are underweight or perceive themselves (accurately or not) to be overweight vary by racial/ethnic group. This suggests girls at weight extremes and those from different racial backgrounds may have unique sexual health education and prevention needs.
PMCID: PMC2947204  PMID: 19841106
adolescent; body weight; sexual behavior; ethnic groups
13.  Weight patterns and perceptions among female university students of Karachi: a cross sectional study 
BMC Public Health  2013;13:230.
Body weight and its perception play an important role in the physical and mental well-being of a person. Weight perception is found to be a better predictor of weight management behaviour as compared to actual weight. In Pakistan, studies have been done on the prevalence of weight status but weight perception is still unexplored. The study was done to examine relationships between body weight perception, actual weight status, and weight control behaviour among the female university students of Karachi.
A cross sectional study was carried out during Sep-Nov 2009 on female students in four universities of Karachi, Pakistan. Our final sample size included 338 female university students. Height and weight were measured on calibrated scales. A modified BMI criterion for Asian populations was used.
Based on measured BMI; the prevalence of underweight, normal weight and overweight females was 27.2%, 51.5% and 21.3% respectively. As a whole, just over one third (33.73%) of the sample misclassified their weight status. Among underweight (n=92), 45.70% thought they were of normal weight. No one who was truly underweight perceived them self as overweight. Among the normal weight (n= 174), 9.8% thought they were underweight and 23.6% considered themselves overweight. Among the overweight (n=72); 18.3% considered themselves normal. Only one female student thought she was underweight despite being truly overweight.
Our study shows that among female university students in Karachi, the prevalence of being underweight is comparatively high. There is a significant misperception of weight, with one third of students misclassifying themselves. Underweight females are likely to perceive themselves as normal and be most satisfied with their weight. Health policy makers should implement these findings in future development of health interventions and prevention of depression, social anxiety and eating disorders associated with incorrect weight perception among young females. Studies that employ a longitudinal approach are needed to validate our findings.
PMCID: PMC3637105  PMID: 23496854
14.  Perception of weight and psychological variables in a sample of Spanish adolescents 
This study explored the relationship between body mass index (BMI) and weight perception, self-esteem, positive body image, food beliefs, and mental health status, along with any gender differences in weight perception, in a sample of adolescents in Spain.
The sample comprised 85 students (53 females and 32 males, mean age 17.4 ± 5.5 years) with no psychiatric history who were recruited from a high school in Écija, Seville. Weight and height were recorded for all participants, who were then classified according to whether they perceived themselves as slightly overweight, very overweight, very underweight, slightly underweight, or about the right weight, using the question “How do you think of yourself in terms of weight?”. Finally, a series of questionnaires were administered, including the Irrational Food Beliefs Scale, Body Appreciation Scale, Self Esteem Scale, and General Health Questionnaire.
Overall, 23.5% of participants misperceived their weight. Taking into account only those with a normal BMI (percentile 5–85), there was a significant gender difference with respect to those who perceived themselves as overweight (slightly overweight and very overweight); 13.9% of females and 7.9% of males perceived themselves as overweight (χ2 = 3.957, P < 0.05). There was a significant difference for age, with participants who perceived their weight adequately being of mean age 16.34 ± 3.17 years and those who misperceived their weight being of mean age 18.50 ± 4.02 years (F = 3.112, P < 0.05).
Misperception of overweight seems to be more frequent in female adolescents, and mainly among older ones. Misperception of being overweight is associated with a less positive body image, and the perception of being very underweight is associated with higher scores for general psychopathology.
PMCID: PMC3139532  PMID: 21792323
weight misperception; self-esteem; positive body image; psychological distress; food beliefs
15.  Bariatric Surgery 
Executive Summary
To conduct an evidence-based analysis of the effectiveness and cost-effectiveness of bariatric surgery.
Obesity is defined as a body mass index (BMI) of at last 30 kg/m2.1 Morbid obesity is defined as a BMI of at least 40 kg/m2 or at least 35 kg/m2 with comorbid conditions. Comorbid conditions associated with obesity include diabetes, hypertension, dyslipidemias, obstructive sleep apnea, weight-related arthropathies, and stress urinary incontinence. It is also associated with depression, and cancers of the breast, uterus, prostate, and colon, and is an independent risk factor for cardiovascular disease.
Obesity is also associated with higher all-cause mortality at any age, even after adjusting for potential confounding factors like smoking. A person with a BMI of 30 kg/m2 has about a 50% higher risk of dying than does someone with a healthy BMI. The risk more than doubles at a BMI of 35 kg/m2. An expert estimated that about 160,000 people are morbidly obese in Ontario. In the United States, the prevalence of morbid obesity is 4.7% (1999–2000).
In Ontario, the 2004 Chief Medical Officer of Health Report said that in 2003, almost one-half of Ontario adults were overweight (BMI 25–29.9 kg/m2) or obese (BMI ≥ 30 kg/m2). About 57% of Ontario men and 42% of Ontario women were overweight or obese. The proportion of the population that was overweight or obese increased gradually from 44% in 1990 to 49% in 2000, and it appears to have stabilized at 49% in 2003. The report also noted that the tendency to be overweight and obese increases with age up to 64 years. BMI should be used cautiously for people aged 65 years and older, because the “normal” range may begin at slightly above 18.5 kg/m2 and extend into the “overweight” range.
The Chief Medical Officer of Health cautioned that these data may underestimate the true extent of the problem, because they were based on self reports, and people tend to over-report their height and under-report their weight. The actual number of Ontario adults who are overweight or obese may be higher.
Diet, exercise, and behavioural therapy are used to help people lose weight. The goals of behavioural therapy are to identify, monitor, and alter behaviour that does not help weight loss. Techniques include self-monitoring of eating habits and physical activity, stress management, stimulus control, problem solving, cognitive restructuring, contingency management, and identifying and using social support. Relapse, when people resume old, unhealthy behaviour and then regain the weight, can be problematic.
Drugs (including gastrointestinal lipase inhibitors, serotonin norepinephrine reuptake inhibitors, and appetite suppressants) may be used if behavioural interventions fail. However, estimates of efficacy may be confounded by high rates of noncompliance, in part owing to the side effects of the drugs. In addition, the drugs have not been approved for indefinite use, despite the chronic nature of obesity.
The Technology
Morbidly obese people may be eligible for bariatric surgery. Bariatric surgery for morbid obesity is considered an intervention of last resort for patients who have attempted first-line forms of medical management, such as diet, increased physical activity, behavioural modification, and drugs.
There are various bariatric surgical procedures and several different variations for each of these procedures. The surgical interventions can be divided into 2 general types: malabsorptive (bypassing parts of the gastrointestinal tract to limit the absorption of food), and restrictive (decreasing the size of the stomach so that the patient is satiated with less food). All of these may be performed as either open surgery or laparoscopically. An example of a malabsorptive technique is Roux-en-Y gastric bypass (RYGB). Examples of restrictive techniques are vertical banded gastroplasty (VBG) and adjustable gastric banding (AGB).
The Ontario Health Insurance Plan (OHIP) Schedule of Benefits for Physician Services includes fee code “S120 gastric bypass or partition, for morbid obesity” as an insured service. The term gastric bypass is a general term that encompasses a variety of surgical methods, all of which involve reconfiguring the digestive system. The term gastric bypass does not include AGB. The number of gastric bypass procedures funded and done in Ontario, and funded as actual out-of-country approvals,2 is shown below.
Number of Gastric Bypass Procedures by Fiscal Year: Ontario and Actual Out-of-Country (OOC) Approvals
Data from Provider Services, MOHLTC
Courtesy of Provider Services, Ministry of Health and Long Term Care
Review Strategy
The Medical Advisory Secretariat reviewed the literature to assess the effectiveness, safety, and cost-effectiveness of bariatric surgery to treat morbid obesity. It used its standard search strategy to retrieve international health technology assessments and English-language journal articles from selected databases. The interventions of interest were bariatric surgery and, for the controls, either optimal conventional management or another type of bariatric procedure. The outcomes of interest were improvement in comorbid conditions (e.g., diabetes, hypertension); short- and long-term weight loss; quality of life; adverse effects; and economic analysis data. The databases yielded 15 international health technology assessments or systematic reviews on bariatric surgery.
Subsequently, the Medical Advisory Secretariat searched MEDLINE and EMBASE from April 2004 to December 2004, after the search cut-off date of April, 2004, for the most recent systematic reviews on bariatric surgery. Ten studies met the inclusion criteria. One of those 10 was the Swedish Obese Subjects study, which started as a registry and intervention study, and then published findings on people who had been enrolled for at least 2 years or at least 10 years. In addition to the literature review of economic analysis data, the Medical Advisory Secretariat also did an Ontario-based economic analysis.
Summary of Findings
Bariatric surgery generally is effective for sustained weight loss of about 16% for people with BMIs of at least 40 kg/m2 or at least 35 kg/m2 with comorbid conditions (including diabetes, high lipid levels, and hypertension). It also is effective at resolving the associated comorbid conditions. This conclusion is largely based on level 3a evidence from the prospectively designed Swedish Obese Subjects study, which recently published 10-year outcomes for patients who had bariatric surgery compared with patients who received nonsurgical treatment. (1)
Regarding specific procedures, there is evidence that malabsorptive techniques are better than other banding techniques for weight loss and resolution of comorbid illnesses. However, there are no published prospective, long-term, direct comparisons of these techniques available.
Surgery for morbid obesity is considered an intervention of last resort for patients who have attempted first-line forms of medical management, such as diet, increased physical activity, behavioural modification, and drugs. In the absence of direct comparisons of active nonsurgical intervention via caloric restriction with bariatric techniques, the following observations are made:
A recent systematic review examining the efficacy of major commercial and organized self-help weight loss programs in the United States concluded that the evidence to support the use of such programs was suboptimal, except for one trial on Weight Watchers. Furthermore, the programs were associated with high costs, attrition rates, and probability of regaining at least 50% of the lost weight in 1 to 2 years. (2)
A recent randomized controlled trial reported 1-year outcomes comparing weight loss and metabolic changes in severely obese patients assigned to either a low-carbohydrate diet or a conventional weight loss diet. At 1 year, weight loss was similar for patients in each group (mean, 2–5 kg). There was a favourable effect on triglyceride levels and glycemic control in the low-carbohydrate diet group. (3)
A decision-analysis model showed bariatric surgery results in increased life expectancy in morbidly obese patients when compared to diet and exercise. (4)
A cost-effectiveness model showed bariatric surgery is cost-effective relative to nonsurgical management. (5)
Extrapolating from 2003 data from the United States, Ontario would likely need to do 3,500 bariatric surgeries per year. It currently does 508 per year, including out-of-country surgeries.
PMCID: PMC3382415  PMID: 23074460
16.  Change in the Body Mass Index Distribution for Women: Analysis of Surveys from 37 Low- and Middle-Income Countries 
PLoS Medicine  2013;10(1):e1001367.
Using cross-sectional surveys, Fahad Razak and colleagues investigate how the BMI (body mass index) distribution is changing for women in low- and middle-income countries.
There are well-documented global increases in mean body mass index (BMI) and prevalence of overweight (BMI≥25.0 kg/m2) and obese (BMI≥30.0 kg/m2). Previous analyses, however, have failed to report whether this weight gain is shared equally across the population. We examined the change in BMI across all segments of the BMI distribution in a wide range of countries, and assessed whether the BMI distribution is changing between cross-sectional surveys conducted at different time points.
Methods and Findings
We used nationally representative surveys of women between 1991–2008, in 37 low- and middle-income countries from the Demographic Health Surveys ([DHS] n = 732,784). There were a total of 96 country-survey cycles, and the number of survey cycles per country varied between two (21/37) and five (1/37). Using multilevel regression models, between countries and within countries over survey cycles, the change in mean BMI was used to predict the standard deviation of BMI, the prevalence of underweight, overweight, and obese. Changes in median BMI were used to predict the 5th and 95th percentile of the BMI distribution. Quantile-quantile plots were used to examine the change in the BMI distribution between surveys conducted at different times within countries. At the population level, increasing mean BMI is related to increasing standard deviation of BMI, with the BMI at the 95th percentile rising at approximately 2.5 times the rate of the 5th percentile. Similarly, there is an approximately 60% excess increase in prevalence of overweight and 40% excess in obese, relative to the decline in prevalence of underweight. Quantile-quantile plots demonstrate a consistent pattern of unequal weight gain across percentiles of the BMI distribution as mean BMI increases, with increased weight gain at high percentiles of the BMI distribution and little change at low percentiles. Major limitations of these results are that repeated population surveys cannot examine weight gain within an individual over time, most of the countries only had data from two surveys and the study sample only contains women in low- and middle-income countries, potentially limiting generalizability of findings.
Mean changes in BMI, or in single parameters such as percent overweight, do not capture the divergence in the degree of weight gain occurring between BMI at low and high percentiles. Population weight gain is occurring disproportionately among groups with already high baseline BMI levels. Studies that characterize population change should examine patterns of change across the entire distribution and not just average trends or single parameters.
Please see later in the article for the Editors' Summary
Editors' Summary
The number of obese people (individuals who have an excessive amount of body fat) is rapidly increasing in many countries. Globally, there were about 200 million obese adults in 1995; by 2010, 475 million adults were obese and another billion were classified as overweight. Obesity is defined as having a body mass index (BMI, an indicator of body fat calculated by dividing a person's weight in kilograms by their height in meters squared) of more than 30.0 kg/m2. Compared to people with a healthy weight (a BMI between 18.5 and 24.9 kg/m2), obese individuals and overweight individuals (who have a BMI between 25.0 and 29.9 kg/m2) have an increased risk of developing diabetes, heart disease and stroke, and tend to die younger. At the same time in many developing countries substantial numbers of people are underweight (BMI <18.5 kg/m2) or have chronic energy deficiency (BMI <16.0 kg/m2) and are at risk of increased risk of dying due to infectious disease or respiratory problems.
Why Was This Study Done?
The global obesity epidemic is usually described in terms of increases in the average BMI or in the prevalence of obesity (the proportion of the population whose BMI is above 30.0 kg/m2). Such descriptions assume that the BMIs of fat and thin people are increasing at the same rate and that the shape of the population's BMI distribution curve remains constant. However, as average BMI and the prevalence of obesity can increase it is unclear how the prevalence of underweight changes. This is potentially important for the health of the population because underweight individuals, like obese individuals, tend to die younger than healthy weight individuals, particularly in low-income countries. In this study, the researchers use repeated cross-sectional survey data collected from low- and middle-income countries in the Demographic and Health Surveys (DHS) to examine changes in BMI in women across the BMI distribution between 1991 and 2008. Repeated cross-sectional surveys collect data from a population at multiple time points from different individuals drawn from the same population, DHS are a data collection and surveillance project that help developing countries track health and population trends.
What Did the Researchers Do and Find?
The researchers used statistical models to analyze data from DHS surveys of more than 730,000 women living in 37 low- and middle-income countries (two to five surveys per country). Increasing average BMI was associated with an increase in the standard deviation of BMI (a measure of the dispersion of BMI in the population) both across and within countries over time. With increasing average BMI, the BMI at both the 5th and 95th percentile increased; 90% of the BMIs in a population lie between these percentiles so these BMI values indicate the spread of the BMI distribution. However, the BMI at the 95th percentile increased about 2.5 times faster than the BMI at the 5th percentile. Moreover, with increasing average BMI, the prevalence of overweight and obesity increased faster than the decline in the prevalence of underweight. Finally, quantile-quantile plots for each country (a graphical method that compares two distributions) revealed a consistent pattern of unequal weight gain across the BMI distribution as average BMI increased, with pronounced weight gains at the obese end of the distribution and little change at the underweight end.
What Do These Findings Mean?
These findings show that increases in average BMI are associated with an increased spread of BMI across and within populations. Consequently, changes in average BMI or single measurements such as the prevalence of overweight do not capture the divergence in the degree of weight gain occurring between that part of the population that has a low BMI and that part that has a high BMI. In other words, at least for the low- and middle-income countries included in this study, population weight gain is occurring disproportionately among groups with high baseline BMI levels. The researchers suggest, therefore, that the characterization of the BMI of populations over time should examine the patterns of change across the whole BMI distribution. Moreover, rather than a single broad population strategy for weight control, optimum health outcomes, they suggest, might be achieved by a strategy that includes targeted interventions to reduce weight in high BMI segments of the population and to increase weight in low BMI segments.
Additional Information
Please access these Web sites via the online version of this summary at
The US Centers for Disease Control and Prevention provides information on all aspects of overweight and obesity (in English and Spanish)
The World Health Organization provides information on obesity (in several languages); Malri's story describes the health risks faced by an obese child
The UK National Health Service Choices website also provides detailed information about obesity and a link to a personal story about losing weight
The International Obesity Taskforce provides information about the global obesity epidemic
The US Department of Agriculture's website provides a personal healthy eating plan; the Weight-control Information Network is an information service provided for the general public and health professionals by the US National Institute of Diabetes and Digestive and Kidney Diseases (in English and Spanish)
MedlinePlus has links to further information about obesity (in English and Spanish)
PMCID: PMC3545870  PMID: 23335861
17.  Far from ideal 
Canadian Family Physician  2007;53(4):678-684.
To examine the prevalence of weight-related concerns, unhealthy weight-control behaviour, and associated risky behaviour among adolescent girls, and to ascertain whether these girls had discussed a healthy weight with their physicians.
Anonymous, self-report, cross-sectional survey.
Four high schools in rural Nova Scotia.
Adolescent girls in grades 10 to 12.
Weight perception, prevalence of weight-control behaviour, associations between weight perception and risky behaviour, associations between disordered eating behaviour and other risky behaviour.
Overall response rate was 76%. Half the 1133 participants saw themselves as not being the “right” weight; 60% were trying to lose weight. During the past 30 days, 16% of the girls were attempting to control or lose weight and had engaged in disordered eating behaviour. In univariate analysis, perception of being either overweight or underweight was significantly associated with suicidal thoughts, suicide planning, and risk of depression. In multivariate analysis, positive associations were found between disordered eating behaviour and suicidal thoughts (odds ratio [OR] 4.2, 95% confidence interval [CI] 2.6 to 6.7), suicide planning (OR 2.9, 95% CI 1.7 to 4.7), suicide attempts (OR 3.4, 95% CI 1.8 to 6.6), and ever having had vaginal intercourse (OR 1.6, 95% CI 1.1 to 2.5). Only 22% of respondents had spoken with a doctor about a healthy weight.
Weight concerns are prevalent among adolescent girls in Nova Scotia. Many of them, especially those who see themselves as overweight or underweight, engage in unhealthy weight-control methods. Perceived underweight and overweight and disordered eating behaviour have strong associations with depression and self-harming behaviour. Few participants had discussed a healthy weight with a physician. Health professionals should be aware of the associations between weight perception and disordered eating behaviour and other risky behaviour.
PMCID: PMC1952598  PMID: 17872719
The objectives of this study were to explore the perception of body weight among students in schools in Jeddah City and identify the main determinants of self-perceived obesity, weight management goals and practices.
Material and Methods:
Data were collected from a sample of Saudi school children of 42 boys’ and 42 girls’ schools in Jeddah city during the month of April 2000. Personal interviews were conducted to collect data on socio-demographic factors, food choices, perception of body weight, weight management goals and weight management practices, as well as the actual measurement of weight and height. Students were asked about their perception of their body weight [responses included: very underweight (thin), slightly underweight, about right weight, slightly overweight and grossly overweight (obese)]. Proportion, prevalence and 95% confidence intervals were calculated. Multiple logistic regression models were fitted to calculate the adjusted odds ratio (OR) for an attempt to lose weight and weight management practices.
The distribution of self-perception of body size was nearly similar to the measured body mass index (BMI) classification except for the overweight students, where 21.3% perceived themselves, as slightly overweight and 5.5% as very overweight although 13.4% were actually overweight and 13.5% were obese by BMI standards. Approximately half the students took at least 3 pieces of fruit or fruit juice servings, and a third ate at least 4 vegetable servings per day. A third of the students managed to lose weight. This coincides with the proportion of those actually overweight and obese. Around 28.0% of the students ate less food, fat or calories, 31.0% took exercise and 17.6% were engaged in vigorous exercise to lose weight or prevent weight gain. Staying for at least 24 hours without food which is a potentially harmful means of weight control was practiced by 10.0% of students. Females were less likely than males to be overweight and obese but more likely to perceive themselves as grossly overweight and more likely to try to lose weight. Factors associated with efforts to lose weight by eating less fat or fewer calories were older age, high social class, being actually obese and perceiving oneself as being obese. Staying for at least 24 hours without eating was mainly practiced by females, older age groups, and the actually obese. Exercise was done mainly by the older age groups, those with educated and highly educated mothers, obese and perceiving oneself as being obese. Vigorous exercise was mainly performed by males, younger age groups, taking < 3 pieces of fruit or fruit juice servings per day, eating < 4 vegetable servings per day, and those perceiving themselves as obese.
Overweight and obesity are prevalent among our youth and not all obese have a correct image of their body size. Highly recommended are intervention programs of education on nutrition starting in childhood through school age to promote and ensure healthy food choices, improve student's awareness of ideal body size and clinical obesity, encourage physical exercise but discourage potentially harmful weight control measures.
PMCID: PMC3430166  PMID: 23008679
Overweight; perceived obesity; diet; physical activity; weight management; children; adolescents
19.  Weight misperception amongst youth of a developing country: Pakistan -a cross-sectional study 
BMC Public Health  2013;13:707.
Weight misperception is the discordance between an individual’s actual weight status and the perception of his/her weight. It is a common problem in the youth population as enumerated by many international studies. However data from Pakistan in this area is deficient.
A multi-center cross-sectional survey was carried out in undergraduate university students of Karachi between the ages of 15–24. Participants were questioned regarding their perception of being thin, normal or fat and it was compared with their Body Mass Index (BMI). Measurements of height and weight were taken for this purpose and BMI was categorized using Asian cut offs. Weight misperception was identified when the self-perceived weight (average, fat, thin) did not match the calculated BMI distribution. Chi square tests and logistic regression tests were applied to show associations of misperception and types of misperception (overestimation, underestimation) with independent variables like age, gender, type of university and faculties. P-value of <0.05 was taken as statistically significant.
42.4% of the total participants i.e. 43.3% males and 41% females misperceived their weight. Amongst those who misperceived 38.2% had overestimated and 61.8% had underestimated their weight. Greatest misperception of was observed in the overweight category (91%), specifically amongst overweight males (95%). Females of the underweight category overestimated their weight and males of the overweight category underestimated their weight. Amongst the total participants, females overestimated 8 times more than males (OR 8.054, 95% CI 5.34-12.13). Misperception increased with the age of the participants (OR 1.114, 95% CI 1.041-1.191). Odds of misperception were greater in students of private sector universities as compared to public (OR 1.861, 95% CI: 1.29-2.67). Odds of misperception were less in students of medical sciences (OR 0.693, 95% CI 0.491-0.977), engineering (OR 0.586, 95% CI 0.364-0.941) and business administration (OR 0.439, 95% CI 0.290-0.662) as compared to general faculty universities.
There was marked discrepancy between the calculated BMI and the self-perceived weight in the youth of Karachi. Better awareness campaigns need to be implemented to reverse these trends.
PMCID: PMC3734050  PMID: 23915180
Weight misperception; BMI; Pakistan; Undergraduate students; Youth; Overweight; Underweight; Overestimation; Underestimation
20.  Improving Questions on Sexual Partnerships: Lessons Learned from Cognitive Interviews for Britain’s Third National Survey of Sexual Attitudes and Lifestyles (“Natsal-3”) 
Archives of Sexual Behavior  2012;42(2):173-185.
Patterns of sexual partnership formation and dissolution are key drivers of sexually transmitted infection transmission. Sexual behavior survey participants may be unable or unwilling to report accurate details about their sexual partners, limiting the potential to capture information on sexual mixing and timing of partnerships. We examined how questions were interpreted, including recall strategies and judgments made in selecting responses, to inform development of a module on recent sexual partnerships in Britain’s third National Survey of Sexual Attitudes and Lifestyles (“Natsal-3”). Face-to-face cognitive interviews were conducted with 14 men and 18 women aged 18–74 years, during development work for Natsal-3. People with multiple recent partners were purposively sampled and questions were presented as a computer-assisted self-interview. Participants were generally agreeable to answering questions about their sexual partners and practices. Interpretation of questions designed to measure concurrent (overlapping) partnerships was broadly consistent with the epidemiological concept of concurrency. Partners’ ages, genders, ethnicity, and participants’ perceptions of whether partner(s) had had concurrent partnerships were reported without offense. Recall problems and lack of knowledge were reported by some participants (of all ages), especially about former, casual, and/or new partnerships, and some reported guessing partners’ ages and dates of sex. Generally, participants were able to answer questions about their sexual partners accurately, even when repeated for multiple partners. Cognitive interviews provided insight into the participants’ understanding of, ability to answer, and willingness to answer questions. This enabled us to improve questions used in previous surveys, refine new questions, and ensure the questionnaire order was logical for participants.
PMCID: PMC3541929  PMID: 22695641
Epidemiology; Sexual partnerships; Sexual mixing; Cognitive interview; Sex surveys
21.  Patterns of Obesity Development before the Diagnosis of Type 2 Diabetes: The Whitehall II Cohort Study 
PLoS Medicine  2014;11(2):e1001602.
Examining patterns of change in body mass index (BMI) and other cardiometabolic risk factors in individuals during the years before they were diagnosed with diabetes, Kristine Færch and colleagues report that few of them experienced dramatic BMI changes.
Please see later in the article for the Editors' Summary
Patients with type 2 diabetes vary greatly with respect to degree of obesity at time of diagnosis. To address the heterogeneity of type 2 diabetes, we characterised patterns of change in body mass index (BMI) and other cardiometabolic risk factors before type 2 diabetes diagnosis.
Methods and Findings
We studied 6,705 participants from the Whitehall II study, an observational prospective cohort study of civil servants based in London. White men and women, initially free of diabetes, were followed with 5-yearly clinical examinations from 1991–2009 for a median of 14.1 years (interquartile range [IQR]: 8.7–16.2 years). Type 2 diabetes developed in 645 (1,209 person-examinations) and 6,060 remained free of diabetes during follow-up (14,060 person-examinations). Latent class trajectory analysis of incident diabetes cases was used to identify patterns of pre-disease BMI. Associated trajectories of cardiometabolic risk factors were studied using adjusted mixed-effects models. Three patterns of BMI changes were identified. Most participants belonged to the “stable overweight” group (n = 604, 94%) with a relatively constant BMI level within the overweight category throughout follow-up. They experienced slightly worsening of beta cell function and insulin sensitivity from 5 years prior to diagnosis. A small group of “progressive weight gainers” (n = 15) exhibited a pattern of consistent weight gain before diagnosis. Linear increases in blood pressure and an exponential increase in insulin resistance a few years before diagnosis accompanied the weight gain. The “persistently obese” (n = 26) were severely obese throughout the whole 18 years before diabetes diagnosis. They experienced an initial beta cell compensation followed by loss of beta cell function, whereas insulin sensitivity was relatively stable. Since the generalizability of these findings is limited, the results need confirmation in other study populations.
Three patterns of obesity changes prior to diabetes diagnosis were accompanied by distinct trajectories of insulin resistance and other cardiometabolic risk factors in a white, British population. While these results should be verified independently, the great majority of patients had modest weight gain prior to diagnosis. These results suggest that strategies focusing on small weight reductions for the entire population may be more beneficial than predominantly focusing on weight loss for high-risk individuals.
Please see later in the article for the Editors' Summary
Editors' Summary
Worldwide, more than 350 million people have diabetes, a metabolic disorder characterized by high amounts of glucose (sugar) in the blood. Blood sugar levels are normally controlled by insulin, a hormone released by the pancreas after meals (digestion of food produces glucose). In people with type 2 diabetes (the commonest form of diabetes) blood sugar control fails because the fat and muscle cells that normally respond to insulin by removing sugar from the blood become insulin resistant. Type 2 diabetes, which was previously called adult-onset diabetes, can be controlled with diet and exercise, and with drugs that help the pancreas make more insulin or that make cells more sensitive to insulin. Long-term complications, which include an increased risk of heart disease and stroke, reduce the life expectancy of people with diabetes by about 10 years compared to people without diabetes. The number of people with diabetes is expected to increase dramatically over the next decades, coinciding with rising obesity rates in many countries. To better understand diabetes development, to identify people at risk, and to find ways to prevent the disease are urgent public health goals.
Why Was This Study Done?
It is known that people who are overweight or obese have a higher risk of developing diabetes. Because of this association, a common assumption is that people who experienced recent weight gain are more likely to be diagnosed with diabetes. In this prospective cohort study (an investigation that records the baseline characteristics of a group of people and then follows them to see who develops specific conditions), the researchers tested the hypothesis that substantial weight gain precedes a diagnosis of diabetes and explored more generally the patterns of body weight and composition in the years before people develop diabetes. They then examined whether changes in body weight corresponded with changes in other risk factors for diabetes (such as insulin resistance), lipid profiles and blood pressure.
What Did the Researchers Do and Find?
The researchers studied participants from the Whitehall II study, a prospective cohort study initiated in 1985 to investigate the socioeconomic inequalities in disease. Whitehall II enrolled more than 10,000 London-based government employees. Participants underwent regular health checks during which their weight and height were measured, blood tests were done, and they filled out questionnaires for other relevant information. From 1991 onwards, participants were tested every five years for diabetes. The 6,705 participants included in this study were initially free of diabetes, and most of them were followed for at least 14 years. During the follow-up, 645 participants developed diabetes, while 6,060 remained free of the disease.
The researchers used a statistical tool called “latent class trajectory analysis” to study patterns of changes in body mass index (BMI) in the years before people developed diabetes. BMI is a measure of human obesity based on a person's weight and height. Latent class trajectory analysis is an unbiased way to subdivide a number of people into groups that differ based on specified parameters. In this case, the researchers wanted to identify several groups among all the people who eventually developed diabetes each with a distinct pattern of BMI development. Having identified such groups, they also examined how a variety of tests associated with diabetes risk, and risks for heart disease and stroke changed in the identified groups over time.
They identified three different patterns of BMI changes in the 645 participants who developed diabetes. The vast majority (606 individuals, or 94%) belonged to a group they called “stable-overweight.” These people showed no dramatic change in their BMI in the years before they were diagnosed. They were overweight when they first entered the study and gained or lost little weight during the follow-up years. They showed only minor signs of insulin-resistance, starting five years before they developed diabetes. A second, much smaller group of 15 people gained weight consistently in the years before diagnosis. As they were gaining weight, these people also had raises in blood pressure and substantial gains in insulin resistance. The 26 remaining participants who formed the third group were persistently obese for the entire time they participated in the study, in some cases up to 18 years before they were diagnosed with diabetes. They had some signs of insulin resistance in the years before diagnosis, but not the substantial gain often seen as the hallmark of “pre-diabetes.”
What Do These Findings Mean?
These results suggest that diabetes development is a complicated process, and one that differs between individuals who end up with the disease. They call into question the common notion that most people who develop diabetes have recently gained a lot of weight or are obese. A substantial rise in insulin resistance, another established risk factor for diabetes, was only seen in the smallest of the groups, namely the people who gained weight consistently for years before they were diagnosed. When the scientists applied a commonly used predictor of diabetes called the “Framingham diabetes risk score” to their largest “stably overweight” group, they found that these people were not classified as having a particularly high risk, and that their risk scores actually declined in the last five years before their diabetes diagnosis. This suggests that predicting diabetes in this group might be difficult.
The researchers applied their methodology only to this one cohort of white civil servants in England. Before drawing more firm conclusions on the process of diabetes development, it will be important to test whether similar results are seen in other cohorts and among more diverse individuals. If the three groups identified here are found in other cohorts, another question is whether they are as unequal in size as in this example. And if they are, can the large group of stably overweight people be further subdivided in ways that suggest specific mechanisms of disease development? Even without knowing how generalizable the provocative findings of this study are, they should stimulate debate on how to identify people at risk for diabetes and how to prevent the disease or delay its onset.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Diabetes Information Clearinghouse provides information about diabetes for patients, health-care professionals, and the general public, including information on diabetes prevention (in English and Spanish)
The UK National Health Service Choices website provides information for patients and carers about type 2 diabetes; it includes people's stories about diabetes
The charity Diabetes UK also provides detailed information about diabetes for patients and carers, including information on healthy lifestyles for people with diabetes, and has a further selection of stories from people with diabetes; the charity Healthtalkonline has interviews with people about their experiences of diabetes
MedlinePlus provides links to further resources and advice about diabetes (in English and Spanish)
More information about the Whitehall II study is available
PMCID: PMC3921118  PMID: 24523667
22.  Associations between health and sexual lifestyles in Britain: findings from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) 
Lancet  2013;382(9907):1830-1844.
Physical and mental health could greatly affect sexual activity and fulfilment, but the nature of associations at a population level is poorly understood. We used data from the third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) to explore associations between health and sexual lifestyles in Britain (England, Scotland, and Wales).
Men and women aged 16–74 years who were resident in households in Britain were interviewed between Sept 6, 2010, and Aug 31, 2012. Participants completed the survey in their own homes through computer-assisted face-to-face interviews and self-interview. We analysed data for self-reported health status, chronic conditions, and sexual lifestyles, weighted to account for unequal selection probabilities and non-response to correct for differences in sex, age group, and region according to 2011 Census figures.
Interviews were done with 15 162 participants (6293 men, 8869 women). The proportion reporting recent sexual activity (one or more occasion of vaginal, oral, or anal sex with a partner of the opposite sex, or oral or anal sex or genital contact with a partner of the same sex in the past 4 weeks) decreased with age after the age of 45 years in men and after the age of 35 years in women, while the proportion in poorer health categories increased with age. Recent sexual activity was less common in participants reporting bad or very bad health than in those reporting very good health (men: 35·7% [95% CI 28·6–43·5] vs 74·8% [72·7–76·7]; women: 34·0% [28·6–39·9] vs 67·4% [65·4–69·3]), and this association remained after adjusting for age and relationship status (men: adjusted odds ratio [AOR] 0·29 [95% CI 0·19–0·44]; women: 0·43 [0·31–0·61]). Sexual satisfaction generally decreased with age, and was significantly lower in those reporting bad or very bad health than in those reporting very good health (men: 45·4% [38·4–52·7] vs 69·5% [67·3–71·6], AOR 0·51 [0·36–0·72]; women: 48·6% [42·9–54·3] vs 65·6% [63·6–67·4], AOR 0·69 [0·53–0·91]). In both sexes, reduced sexual activity and reduced satisfaction were associated with limiting disability and depressive symptoms, and reduced sexual activity was associated with chronic airways disease and difficulty walking up the stairs because of a health problem. 16·6% (95% CI 15·4–17·7) of men and 17·2% (16·3–18·2) of women reported that their health had affected their sex life in the past year, increasing to about 60% in those reporting bad or very bad health. 23·5% (20·3–26·9) of men and 18·4% (16·0–20·9) of women who reported that their health affected their sex life reported that they had sought clinical help (>80% from general practitioners; <10% from specialist services).
Poor health is independently associated with decreased sexual activity and satisfaction at all ages in Britain. Many people in poor health report an effect on their sex life, but few seek clinical help. Sexual lifestyle advice should be a component of holistic health care for patients with chronic ill health.
Grants from the UK Medical Research Council and the Wellcome Trust, with support from the Economic and Social Research Council and Department of Health.
PMCID: PMC3898988  PMID: 24286788
23.  Body size perception and weight control in youth: 9-year international trends from 24 countries 
To examine nine-year trends and relationships regarding misperceptions of body size and dieting for weight loss among adolescents from 24 countries, and explore the influence of country-level overweight prevalence.
Socio-demographic characteristics, body size perception, and dieting for weight loss were assessed in the Health Behaviour in School-aged Children survey conducted in 24 countries cross-sectionally at three time points (2001/02, 2005/06, 2009/10). Logistic regression models examined change over time in overestimation of body size in non-overweight adolescents, underestimation of body size in overweight adolescents, dieting for weight loss in non-overweight and overweight adolescents, and relationships between body size perception and dieting. Analyses were stratified by weight status and sex. Covariates included country-level overweight prevalence, family affluence, and country level of development. Body mass index was only included in models examining dieting for weight loss.
Country-level overweight prevalence increased over time (11.6% to 14.7%). Compared to Time 1, overweight adolescents had greater odds of body size underestimation at Time 3 (OR=1.68 for girls, OR=1.10 for boys), while non-overweight adolescents had lower odds of body size overestimation at Time 3 (OR=0.87 for girls, OR=0.89 for boys). Controlling for country-level overweight prevalence attenuated these relationships. Compared to Time 1, overweight and non-overweight boys were 10% more likely to diet at Time 3, while overweight and non-overweight girls were 19% and 16%, respectively, less likely to diet at Time 3. Controlling for country-level overweight prevalence did not impact trends in dieting for weight loss. Additionally, the association of self-perceived overweight with increased odds of dieting diminished over time.
Body size perceptions among adolescents may have changed over time concurrent with shifts in country-level body weight. However, controlling for country-level overweight prevalence did not impact trends in dieting for weight loss, suggesting a potentially stronger impact of social comparison on weight-related perceptions than on behavior.
PMCID: PMC4090285  PMID: 24722544
Adolescents; body image; dieting; weight perceptions; overweight; development
24.  Misperceived pre-pregnancy body weight status predicts excessive gestational weight gain: findings from a US cohort study 
Excessive gestational weight gain promotes poor maternal and child health outcomes. Weight misperception is associated with weight gain in non-pregnant women, but no data exist during pregnancy. The purpose of this study was to examine the association of misperceived pre-pregnancy body weight status with excessive gestational weight gain.
At study enrollment, participants in Project Viva reported weight, height, and perceived body weight status by questionnaire. Our study sample comprised 1537 women who had either normal or overweight/obese pre-pregnancy BMI. We created 2 categories of pre-pregnancy body weight status misperception: normal weight women who identified themselves as overweight ('overassessors') and overweight/obese women who identified themselves as average or underweight ('underassessors'). Women who correctly perceived their body weight status were classified as either normal weight or overweight/obese accurate assessors. We performed multivariable logistic regression to determine the odds of excessive gestational weight gain according to 1990 Institute of Medicine guidelines.
Of the 1029 women with normal pre-pregnancy BMI, 898 (87%) accurately perceived and 131 (13%) overassessed their weight status. 508 women were overweight/obese, of whom 438 (86%) accurately perceived and 70 (14%) underassessed their pre-pregnancy weight status. By the end of pregnancy, 823 women (54%) gained excessively. Compared with normal weight accurate assessors, the adjusted odds of excessive gestational weight gain was 2.0 (95% confidence interval [CI]: 1.3, 3.0) in normal weight overassessors, 2.9 (95% CI: 2.2, 3.9) in overweight/obese accurate assessors, and 7.6 (95% CI: 3.4, 17.0) in overweight/obese underassessors.
Misperceived pre-pregnancy body weight status was associated with excessive gestational weight gain among both normal weight and overweight/obese women, with the greatest likelihood of excessive gain among overweight/obese underassessors. Future interventions should test the potential benefits of correcting misperception to reduce the likelihood of excessive gestational weight gain.
PMCID: PMC2639379  PMID: 19102729
25.  Words matter: a qualitative investigation of which weight status terms are acceptable and motivate weight loss when used by health professionals 
BMC Public Health  2011;11:513.
Health professionals have an important role to play in the management of obesity, but may be unsure how to raise weight issues with patients. The societal stigma associated with excess weight means that weight status terms may be misunderstood, cause offence and risk upsetting patient-professional relationships. This study investigated the views of people who were overweight or obese on the acceptability of weight status terms and their potential to motivate weight loss when used by health professionals.
A qualitative study comprising 34 semi-structured interviews with men and women in their mid-to-late 30s and 50s who were overweight or obese and had recently been informed of their weight status. Thematic framework analysis was conducted to allow the systematic comparison of views by age, gender and apparent motivation to lose weight.
Although many people favoured 'Overweight' to describe their weight status, there were doubts about its effectiveness to motivate weight loss. Terms including 'BMI' ('Body Mass Index') or referring to the unhealthy nature of their weight were generally considered acceptable and motivational, although a number of men questioned the validity of BMI as an indicator of excess weight. Participants, particularly women, felt that health professionals should avoid using 'Fat'. Whilst response to 'Obese' was largely negative, people recognised that it could be appropriate in a health consultation. Some younger people, particularly those who appeared motivated to lose weight, felt 'Obese' could encourage weight loss, but it was also clear the term could provoke negative emotions if used insensitively.
Although most people who are overweight or obese accept that it is appropriate for health professionals to discuss weight issues with patients, there is great variation in response to the terms commonly used to describe excess weight. There is no one-size-fits-all approach to discussing weight status: some men and younger people may appreciate a direct approach, whilst others need to be treated more sensitively. It is therefore important that health professionals use their knowledge and understanding to select the terms that are most likely to be acceptable, but at the same time have most potential to motivate each individual patient.
PMCID: PMC3142235  PMID: 21714892

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