Few well-controlled trials have evaluated the effects that macronutrient composition has on changes in food cravings during weight loss treatment. The present study, which was part of the POUNDS LOST trial, investigated whether the fat and protein content of four different diets affected changes in specific food cravings in overweight and obese adults. A sample of 811 adults were recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) Moderate fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) Moderate fat (40%), high protein (25%). With few exceptions, the type of diet that participants were assigned did not differentially affect changes in specific food cravings. Participants assigned to the high fat diets, however, had reduced cravings for carbohydrates at Month12 (p< .05) and fruits and vegetables at Month 24. Also, participants assigned to high protein diets had increased cravings for sweets at Month 6 (p< .05). Participants in all four dietary conditions reported significant reductions in food cravings for specific types of foods (i.e., high fat foods, fast food fats, sweets, and carbohydrates/starches; all ps< .05). Cravings for fruits and vegetables, however, were increased at Month 24 (p< .05). Calorically restricted diets (regardless of their macronutrient composition) yielded significant reductions in cravings for fats, sweets, and starches whereas cravings for fruits and vegetables were increased.
Macronutrient composition; Caloric restriction; Food type; Fat; Carbohydrate; Protein
Recent changes in nutrition standards for the National School Lunch and School Breakfast Programs assume that modification of the nutritional serving practices of school cafeterias will result in improved childhood nutrition in the school environment. The primary aim of this paper is to summarize the findings from two recent cluster randomized controlled trials (Wise Mind and LA Health) that tested the hypothesis that modification of school cafeteria environments, including changes in nutrition standards, would yield beneficial changes in childhood nutrition and healthy eating in the school lunch environment. A secondary aim was to investigate the association of participant characteristics and changes in nutrition and healthy eating. A third aim was to investigate the relationships between the food intake of children and: 1) foods selected by the children and 2) food that was uneaten during the lunch meal (plate waste). The studies used similar approaches for modifying the school cafeteria environment and both studies used the digital photography method to measure changes in food intake, food selection, and plate waste. Both studies reported significant improvements in childhood nutrition, and the LA Health study reported improved healthy eating, following introduction of the cafeteria modification program in comparison to baseline and/or control arms. These studies confirm the hypothesis that interventions that modify the school cafeteria environment can beneficially impact childhood nutrition.
childhood nutrition; obesity prevention; cafeteria modification; digital photography; nutrition standards; eating behavior
To investigate the hypotheses that in elementary school students: 1) adiposity and academic achievement are negatively correlated and 2) physical activity and academic achievement are positively correlated.
Participants were 1963 children in fourth through sixth grades. Adiposity was assessed by calculating body mass index (BMI) percentile and percent body fat and academic achievement with statewide standardized tests in four content areas. Socioeconomic status and age were control variables. A subset of participants (n = 261) wore an accelerometer for three days to provide objective measurement of physical activity. Additionally, the association between weight status and academic achievement was examined by comparing children who could be classified as “extremely obese” and the rest of the sample, as well as comparing children who could be classified as normal weight, overweight, or obese. Extreme obesity was defined as >= 1.2 times the 95th percentile.
Results indicated that there were no significant associations between adiposity or physical activity and achievement in students. No academic achievement differences were found between children with BMI percentiles within the extreme obesity range and those who did not fall within the extreme obesity classification. Additionally, no academic achievement differences were found for children with BMI percentiles within the normal weight, overweight, or obese ranges.
These results do not support the hypotheses that increased adiposity is associated with decreased academic achievement or that greater physical activity is related to improved achievement. However, these results are limited by methodological weaknesses, especially the use of cross-sectional data.
childhood; academic achievement; adiposity; physical activity
To identify the most important pretreatment characteristics and changes in psychological and behavioral factors that predict weight outcomes in the Diabetes Prevention Program (DPP).
RESEARCH DESIGN AND METHODS
Approximately 25% of DPP lifestyle intervention participants (n = 274) completed questionnaires to assess weight history and psychological and behavioral factors at baseline and 6 months after completion of the 16-session core curriculum. The change in variables from baseline to 6 months was assessed with t tests. Multivariate models using hierarchical logistic regression assessed the association of weight outcomes at end of study with each demographic, weight loss history, psychological, and behavioral factor.
At end of study, 40.5% had achieved the DPP 7% weight loss goal. Several baseline measures (older age, race, older age when first overweight, fewer self-implemented weight loss attempts, greater exercise self-efficacy, greater dietary restraint, fewer fat-related dietary behaviors, more sedentary activity level) were independent predictors of successful end-of-study weight loss with the DPP lifestyle program. The DPP core curriculum resulted in significant improvements in many psychological and behavioral targets. Changes in low-fat diet self-efficacy and dietary restraint skills predicted better long-term weight loss, and the association of low-fat diet self-efficacy with weight outcomes was explained by dietary behaviors.
Health care providers who translate the DPP lifestyle intervention should be aware of pretreatment characteristics that may hamper or enhance weight loss, consider prioritizing strategies to improve low-fat diet self-efficacy and dietary restraint skills, and examine whether taking these actions improves weight loss outcomes.
networks; mindfulness; food cues; obesity; aging; craving; self-efficacy
Weight loss reduces energy expenditure, but it is unclear whether dietary macronutrient composition affects this reduction. We hypothesized that energy expenditure might be modulated by macronutrient composition of the diet. The POUNDS LOST study, a prospective, randomized controlled trial in 811 overweight/obese people who were randomized in a 2×2 design to diets containing 20en% or 40en% fat and 15en% or 25en% (diets with 65%, 55%, 45% and 35% carbohydrate) provided the data to test this hypothesis. Resting energy expenditure (REE) was measured at baseline, 6 and 24 months using a ventilated hood. REE declined at 6 months by 99.5±8.0 kcal/d in men and 55.2±10.6 kcal/d in women during the first 6 months. This decline was related to the weight loss, and there was no difference between the diets. REE had returned to baseline by 24 months, but body weight was still 60% below baseline. Measured REE at 6 months was significantly lower than the predicted (−18.2±6.7 kcal/d) and was the result of significant reductions from baseline in the low fat diets (65% or 55% carbohydrate), but not in the high fat diet groups. By 24 months the difference had reversed with measured REE being slightly but significantly higher than predicted (21.8±10.1 kcal/d). In conclusion, we found that REE fell significantly after weight loss but was not related to diet composition. Adaptive thermogenesis was evident at 6 months, but not at 24 months.
The use of self-monitoring as a tool to facilitate behavioral modification is common in many lifestyle-based weight loss interventions. Electronic tracking programs, including computer-based systems and smart phone applications, have been developed to allow individuals to self-monitor their behavior digitally. These programs offer an advantage over traditional self-report modalities in that they can provide users with direct feedback about dietary and/or physical activity adherence levels and thereby assist them in real-time decision making. This article describes the use of an Internet-based computerized tracking system (CTS) that was developed specifically for the POUNDS LOST study, a 2-year randomized controlled trial designed to test the efficacy of four macronutrient diets for weight and fat reduction in healthy, overweight men and women (body mass index range = 25.0–39.9 kg/m2). The CTS served many functions in this study, including data collection, dietary and exercise assessment and feedback, messaging system, and report generation. Across all groups, participants with high usage of the CTS during the initial 8 weeks lost greater amounts of weight than participants with low usage (8.7% versus 5.5% of initial body weight, respectively; p < .001) at week 32. Rates of CTS utilization were highest during the first year of this 2-year intervention, and utilization of the CTS declined steadily over time. The unique features of the CTS combined with technological developments, such as smart phone applications, offer significant potential to improve the user’s self-monitoring experience and adherence to health promotion programs designed specifically for individuals with obesity and type 2 diabetes.
computerized tracking system; self-monitoring; smart phones; weight loss
The Power of Food Scale (PFS) is a new measure that assesses the drive to consume highly palatable food in an obesogenic food environment. The data reported in this investigation evaluate whether the PFS moderates state cravings, control beliefs, and brain networks of older, obese adults following either a short-term post-absorptive state, in which participants were only allowed to consume water, or a short-term energy surfeit treatment condition, in which they consumed BOOST®. We found that the short-term post-absorptive condition,in which participants consumed water only, was associated withincreases in state cravings for desired food, a reduction in participants' confidence related to the control of eating behavior, and shifts in brain networks that parallel what is observed with other addictive behaviors. Furthermore, individuals who scored high on the PFSwere at an increased risk for experiencing these effects. Future research is needed to examine the eating behavior of persons who score high on the PFS and to develop interventions that directly target food cravings.
aging; brain networks; food; cravings; self-efficacy
Animal studies have shown that life span is extended by caloric restriction (CR). This manuscript describes the design and methodology of an innovative CR intervention, which is the treatment arm of the CALERIE study. This study is a multi-center, randomized controlled trial examining the effects of two years of CR on biomarkers of longevity among non-obese (BMI ≥ 22 kg/m2 and < 28 kg/m2) adults. CALERIE is the first investigation of the effects of long-term CR on the aging process in non-obese humans. 220 healthy volunteers across 3 sites were recruited beginning in May 2007. Participants were randomized in a 2:1 ratio between the CR or Control group (i.e., ad libitum diet). An intensive intervention was designed to assist participants in adhering to the 25% CR prescription for a two-year duration. The intervention was designed to optimize the likelihood 25% CR would be achieved through a variety of nutritional and behavioral strategies, several of which are innovative methods for achieving CR. The intervention includes the following components: an intensive, “mixed” format schedule of group/individual sessions, meal provision phase with exposure to various diets, Personal Digital Assistants to monitor caloric intake, unique portion estimation training, tailored treatment using a computer tracking system, toolbox strategies and algorithms, as well as comprehensive coverage of nutrition and behavioral topics in order to assist participants in meeting their CR goal. This manuscript provides an overview of the CR intensive intervention and may be of assistance for other researchers and clinicians in designing future trials.
Caloric restriction; randomized controlled trial; aging; intervention
The primary aims of this article are to describe the utilization of an Internet-based weight management Web site [Healthy Eating, Activity, and Lifestyle Training Headquarters (H.E.A.L.T.H.)] over a 12–27 month period and to describe concurrent weight and fitness changes in Army Reserve soldiers.
The H.E.A.L.T.H. Web site was marketed to Army Reserve soldiers via a Web site promotion program for 27 months (phase I) and its continued usage was observed over a subsequent 12-month period (phase II). Web site usage was obtained from the H.E.A.L.T.H. Web site. Weight and fitness data were extracted from the Regional Level Application Software (RLAS).
A total of 1499 Army Reserve soldiers registered on the H.E.A.L.T.H. Web site. There were 118 soldiers who returned to the H.E.A.L.T.H. Web site more than once. Registration rate reduced significantly following the removal of the Web site promotion program. During phase I, 778 Army Reserve soldiers had longitudinal weight and fitness data in RLAS. Men exceeding the screening table weight gained less weight compared with men below it (p < .007). Percentage change in body weight was inversely associated with change in fitness scores.
The Web site promotion program resulted in 52% of available Army Reserve soldiers registering onto the H.E.A.L.T.H. Web site, and 7.9% used the Web site more than once. The H.E.A.L.T.H. Web site may be a viable population-based weight and fitness management tool for soldier use.
Army Reserve; Internet; military; obesity prevention; weight management
Weight loss reduces energy expenditure, but the contribution of different macronutrients to this change is unclear.
We tested the hypothesis that macronutrient composition of the diet might affect the partitioning of energy expenditure during weight loss.
A sub-study of 99 participants from the POUNDS LOST trial had total energy expenditure (TEE) measured by doubly labeled water and resting energy expenditure (REE) measured by indirect calorimetry at baseline and repeated at 6 months in 89 participants. Participants were randomly assigned to one of 4 diets with either 15% or 25% protein and 20% or 40% fat.
TEE and REE were positively correlated with each other and with fat free mass and body fat, at baseline and 6 months. The average weight loss of 8.1±0.65 kg (LSmean±SE) reduced TEE by 120±56 kcal/d and REE by 136±18 kcal/d. A greater weight loss at 6 months was associated with a greater decrease in TEE and REE. Participants eating the high fat diet lost significantly more fat free mass (1.52±0.55 kg) than the low fat diet group (p<0.05). Participants eating the low fat diet had significantly higher measures of physical activity than the high fat group.
A greater weight loss was associated with a larger decrease in both TEE and REE. The low fat diet was associated with significant changes in fat free body mass and energy expenditure from physical activity compared to the high fat diet.
Objective measures are needed to quantify dietary adherence during caloric restriction (CR) while participants are free-living. One method to monitor adherence is to compare observed weight loss to the expected weight loss during a prescribed level of CR. Normograms (graphs) of expected weight loss can be created from mathematical modeling of weight change to a given level of CR, conditional on the individual's set of baseline characteristics. These normograms can then be used by counselors to help the participant adhere to their caloric target.
(1) To develop models of weight loss over a year of caloric restriction given demographics (age and sex), and well defined measurements of of Body Mass Index, total daily energy expenditure (TDEE) and %CR. (2) To utilize these models to develop normograms given level of caloric restriction, and measures of these variables.
Seventy-seven individuals completing a 6-12 month CR intervention (CALERIE) had body weight and body composition measured frequently. Energy intake (and %CR) was estimated from TDEE (by doubly labeled water) and body composition (by DXA) at baseline and months 1, 3, 6 and 12. Body weight was modeled to determine the predictors and distribution of the expected trajectory of percent weight change over 12 months of caloric restriction.
As expected, CR was related to change in body weight. Controlling for time-varying measures, initially simple models of the functional form indicated that the trajectory of percent weight change was predicted by a non-linear function of initial age, TDEE, %CR, and sex. Using these estimates, normograms for the weight change expected during a 25%CR were developed. Our model estimates that the mean weight loss (% change from baseline weight) for an individual adherent to a 25% CR regimen is -10.9±6.3% for females and -13.9±6.4% for men after 12 months.
There are several limitations. Sample sizes are small (n=77), and, by design, the protocols, including prescribed CR, for the interventions differed by site, and not all subjects completed a year of follow-up. In addition, the inclusion of subjects by age and initial BMI was constricted so that these results may no generalize to other older, obese subjects.
The trajectory of percent weight change during CR interventions in the presence of well measured covariates can be modeled using simple non-linear functions, and is related level of CR, the percent change in TDEE, gender, and age. Displayed on a normogram, individually tailored trajectories can be used by counselors and participants to monitor weight loss and adherence to a CR regimen.
A significant number of soldiers exceed the maximum allowable weight standards or have body weights approaching the maximum allowable weight standards. This mandates development of scalable approaches to improve compliance with military weight standards.
We developed an intervention that included two components: (1) an Internet-based weight management program (Web site) and (2) a promotion program designed to promote and sustain usage of the Web site. The Web site remained online for 37 months, with the Web site promotion program ending after 25 months.
Soldiers’ demographics were as follows: mean age, 32 years; body mass index (BMI), 28 kg/m2; 31% female; and 58% Caucasian. Civilian demographics were as follows: mean age, 38 years; BMI, 30 kg/m2; 84% female; and 55% Caucasian. Results indicated that 2417 soldiers and 2147 civilians (N = 4564) registered on the Web site. In the first 25 months (phase 1) of the study, new participants enrolled on the Web site at a rate of 88 (soldiers) and 80 (civilians) per month. After the promotion program was removed (phase 2), new participants enrolled at a rate of 18 (soldiers) and 13 (civilians) per month. Utilization of the Web site was associated with self-reported weight loss (p < .0001). Participants who utilized the Web site more frequently lost more weight (p < .0001). Participants reported satisfaction with the Web site.
The Web site and accompanying promotion program, when implemented at a military base, received satisfactory ratings and benefited a subset of participants in promoting weight loss. This justifies further examination of effectiveness in a randomized trial setting.
Army; Internet weight management; military; obesity; obesity prevention; weight loss
The obesity epidemic had spawned considerable interest in understanding peoples' responses to palatable food cues that are plentiful in obesogenic environments. In this paper we examine how trait mindfulness of older, obese adults may moderate brain networks that arise from exposure to such cues. Nineteen older, obese adults came to our laboratory on two different occasions. Both times they ate a controlled breakfast meal and then were restricted from eating for 2.5 h. After this brief period of food restriction, they had an fMRI scan in which they were exposed to food cues and then underwent a 5 min recovery period to evaluate brain networks at rest. On one day they consumed a BOOST® liquid meal prior to scanning, whereas on the other day they only consumed water (NO BOOST® condition). We found that adults high in trait mindfulness were able to return to their default mode network (DMN), as indicated by greater global efficiency in the precuneus, during the post-exposure rest period. This effect was stronger for the BOOST® than NO BOOST® treatment condition. Older adults low in trait mindfulness did not exhibit this pattern in the DMN. In fact, the brain networks of those low on the MAAS suggests that they continued to be pre-occupied with the elaboration of food cues even after cue exposure had ended. Further work is needed to examine whether mindfulness-based therapies alter brain networks to food cues and whether these changes are related to eating behavior.
networks; mindfulness; food cues; obesity; aging; craving; self-efficacy
Research on the conceptualization of adherence to treatment has not addressed a key question: Is adherence best defined as being a uni-dimensional or multi-dimensional behavioral construct? The primary aim of this study was to test which of these conceptual models best described adherence to a weight management program. This ancillary study was conducted as a part of the POUNDS LOST trial that tested the efficacy of four dietary macro-nutrient compositions for promoting weight loss. A sample of 811 overweight/obese adults was recruited across two clinical sites, and each participant was randomly assigned to one of four macronutrient prescriptions: (1) Low fat (20% of energy), average protein (15% of energy); (2) High fat (40%), average protein (15%); (3) Low fat (20%), high protein (25%); (4) High fat (40%), high protein (25%). Throughout the first 6 months of the study, a computer tracking system collected data on eight indicators of adherence. Computer tracking data from the initial 6 months of the intervention were analyzed using exploratory and confirmatory analyses. Two factors (accounting for 66% of the variance) were identified and confirmed: (1) behavioral adherence and (2) dietary adherence. Behavioral adherence did not differ across the four interventions, but prescription of a high fat diet (vs. a low fat diet) was found to be associated with higher levels of dietary adherence. The findings of this study indicated that adherence to a weight management program was best conceptualized as being multi-dimensional, with two dimensions: behavioral and dietary adherence.
Adherence; Overweight; Obesity; Randomized controlled trial; Lifestyle behavior modification
The primary aim of this study was to test the association of early (first 6 months) adherence related to diet, self-monitoring, and attendance with changes in adiposity and cardiovascular risk factors. This study used data from the 24-month POUNDS LOST trial that tested the efficacy of four dietary macronutrient compositions for short-and long-term weight loss. A computer tracking system was used to record data on eight indicator variables related to adherence. Using canonical correlations at the 6 and 24 month measurement periods, early behavioral adherence was associated with changes in percent weight loss and waist circumference at 6 months (R = 0.52) and 24 months (R = 0.37), but was not associated with cardiovascular disease risk factor levels. Early dietary adherence was associated with changes in insulin at 6 months (R = 0.19), but not at 24 months (R = 0.08, ns). Early dietary adherence was not associated with changes in adiposity.
Obesity; Weight management; Adherence; Computer tracking; Waist circumference; Insulin
Examine the influence of an environmental intervention to prevent excess weight gain in African American children.
Single-group repeated measures.
The intervention was delivered to a school composed of African American children.
Approximately 45% (N = 77) of enrolled second through sixth grade students.
The 18-month intervention was designed to alter the school environment to prevent excess weight gain by making healthier eating choices and physical activity opportunities more available.
Body Mass Index Percentile was the primary outcome variable. Body mass index Z-score was also calculated, and percent body fat, using bioelectrical impedance, was also measured. Total caloric intake (kcal), and percent kcal from fat, carbohydrate, and protein were measured by digital photography. Minutes of physical activity and sedentary behavior were self-reported.
Mixed models analysis was used, covarying baseline values.
Boys maintained while girls increased percent body fat over 18-months (p = .027). All children decreased percent of kcal consumed from total and saturated fat, and increased carbohydrate intake and self-reported physical activity during the intervention (p values < .025). body mass index Z-score, sedentary behavior, and total caloric intake were unchanged.
The program may have resulted in maintenance of percent body fat in boys. Girl's percent body fat steadily increased, despite similar behavioral changes as boys. School-based interventions targeting African American children should investigate strategies that can be effective across gender.
blacks; obesity; children; nutrition; physical activity; Manuscript format: research; Research purpose: intervention testing/program evaluation; Study design: quasi-experimental; Outcome measure: behavioral; Setting: school; Health focus: weight control; Strategy: environmental change; Target population age: youth; Target population circumstances: race/ethnicity
Childhood obesity is a growing problem, particularly in rural, Louisiana school children. Traditionally, school-based obesity prevention programs have used a primary prevention approach. Finding methods to deliver secondary prevention programs to large numbers of students without singling out overweight students has been a challenge. An innovative approach to achieving this goal is through use of an Internet intervention targeted toward a student's weight status. This article describes the Louisiana (LA) Health Internet intervention, including the student Web site, the Internet counselor Web site, and the Internet counseling process.
The LA Health Internet intervention had separate interfaces for students and Internet counselors. The main features of the student site were behavioral weight loss lessons, lesson activities, chat with an Internet counselor, and email. The Internet counselor site contained these same features, plus a student directory and various means of obtaining student information to guide counseling. Based on their baseline weight status, students received lessons and counseling that promoted either weight loss or weight maintenance. Intervention was delivered during class time, and teachers scheduled Internet counseling sessions with intervention personnel.
The LA Health Internet intervention was initially implemented within 14 schools; 773 students were granted access to the site. From Fall 2007 to Spring 2009, 1174 hours of Internet counselor coverage was needed to implement the Internet counseling component of this intervention
The LA Health Internet intervention is an innovative and feasible method of delivering a secondary prevention program within a school setting to large numbers of students.
children; counseling; Internet; obesity; school; weight management
Lifespan in rodents is prolonged by caloric restriction (CR) and by mutations affecting the somatotropic axis. It is not known if CR can alter the age-associated decline in GH, IGF-1 and GH secretion.
To evaluate the effect of caloric restriction on GH secretory dynamics.
Forty-three young (36.8±1.0y), overweight (BMI 27.8±0.7) men (n=20) and women (n=23) were randomized into four groups; Control=100% of energy requirements; CR=25% calorie restriction; CR+EX=12.5% CR+12.5% increase in energy expenditure by structured exercise; LCD=low calorie diet until 15% weight reduction followed by weight maintenance. At baseline and after six months, body composition (DXA), abdominal visceral fat (CT) 11-h GH secretion (blood sampling every 10 min for 11 hours; 2100h-0800h) and deconvolution analysis were measured.
After six months, weight (Control:−1±1%, CR:−10±1%, CR+EX:−10±1%, LCD:−14±1%), fat mass (Control:−2±3%, CR:−24±3%, CR+EX:−25±3%, LCD:−31±2%), and visceral fat (Control: −2±4%, CR:−28±4%, CR+EX:−27±3%, LCD:−36±2%) were significantly (p<.001) reduced in the three intervention groups compared to control. Mean 11-h GH concentrations were not changed in CR or control but increased in CR+EX (p<.0001) and LCD (p<.0001) because of increased secretory burst mass (CR+EX: 34±13%, LCD: 27±22%, p<0.05) and amplitude (CR+EX: 34±14%, LCD: 30±20%, p<0.05) but not to changes in secretory burst frequency or GH half-life. Fasting ghrelin was significantly increased from baseline in all three intervention groups however total IGF-1 concentrations were increased only in CR+EX (10±7%, p<0.05) and LCD (19±4%, p<0.001).
A 25% CR diet for 6 months does not change GH, GH secretion or IGF-1 in non-obese men and women.
caloric restriction; GH; IGF-1; aging
Consumption of sugar-sweetened beverages may be one of the dietary causes of metabolic disorders, such as obesity. Therefore, substituting sugar with low-calorie sweeteners may be an efficacious weight management strategy. We tested the effect of preloads containing stevia, aspartame, or sucrose on food intake, satiety, and postprandial glucose and insulin levels. Design: 19 healthy lean (BMI = 20.0 – 24.9) and 12 obese (BMI = 30.0 – 39.9) individuals 18 to 50 years old completed three separate food test days during which they received preloads containing stevia (290 kcal), aspartame (290 kcal), or sucrose (493 kcal) before the lunch and dinner meal. The preload order was balanced, and food intake (kcal) was directly calculated. Hunger and satiety levels were reported before and after meals, and every hour throughout the afternoon. Participants provided blood samples immediately before and 20 minutes after the lunch preload. Despite the caloric difference in preloads (290 vs. 493 kcals), participants did not compensate by eating more at their lunch and dinner meals when they consumed stevia and aspartame versus sucrose in preloads (mean differences in food intake over entire day between sucrose and stevia = 301 kcal, p < .01; aspartame = 330 kcal, p < .01). Self-reported hunger and satiety levels did not differ by condition. Stevia preloads significantly lowered postprandial glucose levels compared to sucrose preloads (p < .01), and postprandial insulin levels compared to both aspartame and sucrose preloads (p < .05). When consuming stevia and aspartame preloads, participants did not compensate by eating more at either their lunch or dinner meal and reported similar levels of satiety compared to when they consumed the higher calorie sucrose preload.
Stevia; Aspartame; Sucrose; Food Intake; Satiety; Hunger; Insulinogenic Index; Insulin Sensitivity
Calorie restriction (CR) delays the development of age-associated disease and increases lifespan in rodents, but the effects in humans remain uncertain.
Determine the effect of 6 months of CR with or without exercise on cardiovascular disease (CVD) risk factors and estimated 10-year CVD risk in healthy non-obese men and women.
Thirty-six individuals were randomized to one of three groups for 6 months: Control, 100% of energy requirements; CR, 25% calorie restriction; CR+EX, 12.5% CR + 12.5% increase in energy expenditure via aerobic exercise. CVD risk factors were assessed at baseline, 3 and 6 months.
After 6 months, CR and CR+EX lost approximately 10% of body weight. CR significantly reduced triacylglycerol (-31 ± 15 mg/dL) and factor VIIc (-10.7 ± 2.3%). Similarly CR+EX reduced triacylglycerol (-22 ± 8 mg/dL) and additionally reduced LDL-C (-16.0 ± 5.1 mg/dL) and DBP (-4.0 ± 2.1 mmHg). In contrast, both triacylglycerol (24 ± 14 mg/dL) and factor VIIc (7.9 ± 2.3%) were increased in the control group. HDL-cholesterol was increased in all groups while hsCRP was lower in the Controls vs. CR+EX. Estimated 10-year CVD risk significantly declined from baseline by 29% in CR (P< 0.001) and 38% in the CR+EX (P<0.001) while remaining unchanged in the Control group.
Based on combined favorable changes in lipid and blood pressure, caloric restriction with or without exercise that induces weight loss favorably reduces risk for CVD even in already healthy non-obese individuals.
caloric restriction; exercise; cardiovascular risk factors; nutritional intervention; weight loss; aging
Inconsistent findings have been reported regarding improved health-related quality of life (HRQOL) following weight loss.
To test the efficacy of a weight management program for improving HRQOL in overweight/obese adults diagnosed with type 2 diabetes.
Randomized multi-site clinical trial with two treatment arms and blinded measurements at baseline and end of Year 1.
Study was conducted at 16 outpatient research centers.
Total of 5,145 participants (mean age = 58.7±6.9 yr; mean BMI = 36.0±5.9; % women = 59.5%; % white = 63.3%) were randomized to two treatment arms.
The two treatment arms were: Intensive Lifestyle Intervention 1 and Diabetes Support and Education (DSE).
Main Outcome Measures
SF-36, physical (PCS) and mental health (MCS) summary scores, and Beck Depression Inventory-II (BDI-II) scores. Baseline means were: PCS = 47.9±7.9; MCS = 54.0±8.1; and BDI-II = 5.7±5.0.
HRQOL, as measured by PCS and BDI-II scores, improved (p<0.001) in the ILI arm compared to the DSE arm. The largest effect was observed for PCS (difference = −2.91, 99% CI: −3.44 ~ −2.37). HRQOL improved greatest in participants with the lowest baseline levels of quality of life. Changes in weight (ILI = −8.77±8.2 kg; DSE = −0.86±5.0 kg), improved fitness, and improved physical complaints mediated treatment effects associated with BDI-II and PCS.
HRQOL was significantly improved in overweight adults diagnosed with type 2 diabetes by enrollment in a weight management program that yielded significant weight loss, improved physical fitness, and reduced physical complaints. Trial Registration: NCT00017953
Rates of obesity among children have been rising in recent years. Information on the prevalence of obesity in children living in rural communities is needed. We report the prevalence of overweight and obesity in children enrolled in grades 4 to 6 who live in rural areas of Louisiana, U.S.
Methods and Procedures
These data were collected as baseline assessment for the Louisiana (LA) Health project. Height, weight, and estimates of body fat (using body impedance analysis) were collected on 2709 children. Average age was 10.5 years and the sample composition was 57.3% girls, 61.7% African-American, 36.0% Caucasian, and 2.3% other minority. A majority of children (77%) met the criterion for poverty status.
The distribution of body mass index (BMI) percentile was highly skewed toward obesity. The most frequent BMI percentile scores were 98th and 99th percentile. Using Centers for Disease Control and Prevention (CDC) norms, the overall prevalence of obesity was 27.4% and for overweight was 45.1% of which 17.7% were between the 85th and 95th percentile. The prevalence of childhood overweight and obesity were much higher than the national norm and this increased prevalence was observed in both genders and in Caucasian and African American children.
The prevalence of childhood overweight and obesity was found to be much higher in rural and primarily poor (77%) children living in Louisiana when compared to national norms. This observation suggests that rural children from Louisiana may be experiencing an epidemic of obesity that exceeds national prevalence estimates.
childhood obesity; population studies; rural health; childhood gender differences; ethnicity
Binge eating (BE) is common in overweight and obese individuals with type 2 diabetes yet little is known about how BE affects weight loss in this population.
To determine whether BE was related to 1-year weight losses in overweight and obese individuals with type 2 diabetes participating in an ongoing clinical trial.
Design and Setting
Look AHEAD is a randomized controlled trial examining the long-term effect of intentional weight loss on CVD in overweight and obese adults with type 2 diabetes.
Overweight and obese individuals, 45–76 years old, with type 2 diabetes (n=5145).
Participants were randomly assigned to an intensive lifestyle intervention (ILI) or to enhanced usual care (DSE).
Main outcome measures
At baseline and 1-year, participants had their weight measured and completed a fitness test and self-report measures of BE and dietary intake. Four groups were created based on BE status at baseline and 1-year (Yes/Yes, No/No, Yes/No, No/Yes). Analyses controlled for baseline differences between binge eaters and non-binge eaters.
Most individuals (85.4%) did not report BE at baseline or 1-year, 7.5% reported BE only at baseline, 3.7% reported BE at both times, and 3.4% reported BE only at 1-year, with no differences between ILI and DSE conditions (p=.14). Across ILI and DSE, greater weight losses were observed in participants who stopped BE at 1-year (5.3±.4 kg) and in those who reported no BE at either time point (4.8±.1 kg) than in those who continued to BE (3.1±.6 kg) and those who began BE at 1-year (3.0±.6 kg) (p=.0003). Post hoc analyses suggested these differences were due to changes in caloric intake.
Overweight and obese individuals with type 2 diabetes who stop binge eating appear just as successful at weight loss as non-binge eaters after one year of treatment.
The possible advantage for weight loss of a diet that emphasizes protein, fat, or carbohydrates has not been established, and there are few studies that extend beyond 1 year.
We randomly assigned 811 overweight adults to one of four diets; the targeted percentages of energy derived from fat, protein, and carbohydrates in the four diets were 20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%. The diets consisted of similar foods and met guidelines for cardiovascular health. The participants were offered group and individual instructional sessions for 2 years. The primary outcome was the change in body weight after 2 years in two-by-two factorial comparisons of low fat versus high fat and average protein versus high protein and in the comparison of highest and lowest carbohydrate content.
At 6 months, participants assigned to each diet had lost an average of 6 kg, which represented 7% of their initial weight; they began to regain weight after 12 months. By 2 years, weight loss remained similar in those who were assigned to a diet with 15% protein and those assigned to a diet with 25% protein (3.0 and 3.6 kg, respectively); in those assigned to a diet with 20% fat and those assigned to a diet with 40% fat (3.3 kg for both groups); and in those assigned to a diet with 65% carbohydrates and those assigned to a diet with 35% carbohydrates (2.9 and 3.4 kg, respectively) (P>0.20 for all comparisons). Among the 80% of participants who completed the trial, the average weight loss was 4 kg; 14 to 15% of the participants had a reduction of at least 10% of their initial body weight. Satiety, hunger, satisfaction with the diet, and attendance at group sessions were similar for all diets; attendance was strongly associated with weight loss (0.2 kg per session attended). The diets improved lipid-related risk factors and fasting insulin levels.
Reduced-calorie diets result in clinically meaningful weight loss regardless of which macronutrients they emphasize.