The concept of ‘Successful Aging’ has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. The domain in which consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults.
age; mobility; obesity; sarcopenia; healthspan; longevity
Reducing consumption of food away from home (FAFH) is often targeted during pediatric obesity treatment given associations with weight status and gain. However, the effects of this dietary change on weight loss are unknown.
Evaluate associations between changes in dietary factors and child anthropometric outcomes after treatment. It is hypothesized that reduced consumption of FAFH will be associated with improved dietary intake and greater reductions in anthropometric outcomes (standardized body mass index [zBMI] and percent body fat), and the relationship between FAFH and anthropometric outcomes will be mediated by improved child dietary intake.
Longitudinal evaluation of associations between dietary changes and child anthropometric outcomes. Child diet (three 24-hour recalls) and anthropometric data were collected at baseline and 16-weeks.
170 overweight and obese children ages 7–11 who completed 16-week family-based behavioral weight loss treatment (FBT) as part of a larger multi-site (MO and WA) randomized controlled trial (RCT) conducted in two cohorts between 2010–2011. Clinical research trial.
Dietary treatment targets during FBT included improving diet quality and reducing FAFH.
Main Outcome Measures
Child relative weight (zBMI) and body composition (percent body fat)
Statistical Analyses Performed
T-tests, bootstrapped single mediation analyses adjusting for relevant covariates.
As hypothesized, decreased FAFH was associated with improved diet quality and greater reductions in zBMI (Ps<0.05) and percent body fat (Ps<0.01). Associations between FAFH and anthropometric outcomes were mediated by changes in diet quality. Specifically, change in total energy intake and added sugars mediated the association between change in FAFH and zBMI, and change in overall diet quality, fiber, added sugars, and added fats mediated the association between change in FAFH and percent body fat. Including physical activity as a covariate did not significantly impact these findings.
These results suggest that reducing FAFH may be an important behavioral target for affecting positive changes in both diet quality and anthropometric outcomes during treatment.
pediatric; obesity; food away from home; diet quality
The purpose of this systematic review was to evaluate, synthesize, and interpret findings from recent randomized controlled trials (RCTs) of dietary and lifestyle weight loss interventions examining the effects of 1) diet composition, 2) use of food provision, and 3) modality of treatment delivery on weight loss. Trials comparing different dietary approaches indicated that reducing carbohydrate intake promoted greater initial weight loss than other approaches but did not appear to significantly improve long-term outcomes. Food provision appears to enhance adherence to reduction in energy intake and produce greater initial weight losses. The long-term benefits of food provision are less clear. Trials comparing alternative treatment modalities suggest that phone-based treatment produce short- and long-term weight reductions equivalent to face-to-face interventions. The use of Internet and mobile technologies are associated with smaller reductions in body weight than face-to-face interventions. Based on this review, clinical implications and future research directions are provided.
obesity; weight loss; cardiovascular disease; lifestyle intervention; behavioral treatment; diet; systematic review; randomized controlled trial; adults
To evaluate the effects and costs of three doses of behavioral weight-loss treatment delivered via Cooperative Extension Offices in rural communities.
Design and Methods
Obese adults (N=612) were randomly assigned to low, moderate or high doses of behavioral treatment (i.e., 16, 32 or 48 sessions over two years) or to a control condition that received nutrition education without instruction in behavior modification strategies.
Two-year mean reductions in initial body weight were 2.9% (95% Credible Interval=1.7–4.3), 3.5% (2.0–4.8), 6.7% (5.3–7.9), and 6.8% (5.5–8.1) for the control, low, moderate, and high-dose conditions, respectively. The moderate-dose treatment produced weight losses similar to the high-dose condition and significantly larger than the low-dose and control conditions (posterior probability > .996). The percentages of participants who achieved weight reductions ≥ 5% at two years were significantly higher in the moderate-dose (58%) and high-dose (58%) conditions compared with low-dose (43%) and control (40%) conditions (posterior probability > .996). Cost-effectiveness analyses favored the moderate-dose treatment over all other conditions.
A moderate dose of behavioral treatment produced two-year weight reductions comparable to high-dose treatment but at a lower cost. These findings have important policy implications for the dissemination of weight-loss interventions into communities with limited resources.
ClinicalTrials.gov number, NCT00912652.
Behavior Therapy; Cost effectiveness; Weight Management Programs; Treatment Outcomes; Dissemination
Physical activity is essential for chronic disease prevention, yet <40% of overweight/obese adults meet national activity recommendations. For time-efficient counseling, clinicians need a brief easy-to-use tool that reliably and validly assesses a full range of activity levels, and most importantly, is sensitive to clinically meaningful changes in activity. The Stanford Leisure-Time Activity Categorical Item (L-Cat) is a single item comprised of six descriptive categories ranging from inactive to very active. This novel methodological approach assesses national activity recommendations as well as multiple clinically relevant categories below and above recommendations, and incorporates critical methodological principles that enhance psychometrics (reliability, validity, sensitivity to change).
We evaluated the L-Cat’s psychometrics among 267 overweight/obese women asked to meet national activity recommendations in a randomized behavioral weight-loss trial.
The L-Cat had excellent test-retest reliability (κ=0.64, P<.001) and adequate concurrent criterion validity; each L-Cat category at 6 months was associated with 1059 more daily pedometer steps (95% CI 712–1407, β=0.38, P<.001) and 1.9% greater initial weight loss at 6 months (95% CI −2.4 to −1.3, β=−0.38, P<.001). Of interest, L-Cat categories differentiated from each other in a dose-response gradient for steps and weight loss (Ps<.05) with excellent face validity. The L-Cat was sensitive to change in response to the trial’s activity component. Women increased one L-Cat category at 6 months (M=1.0±1.4, P<.001); 55.8% met recommendations at 6 months whereas 20.6% did at baseline (P<.001). Even among women not meeting recommendations at both baseline and 6 months (n=106), women who moved ≥1 L-Cat categories at 6 months lost more weight than those who did not (M=−4.6%, 95% CI −6.7 to −2.5, P<.001).
Given strong psychometrics, the L-Cat has timely potential for clinical use such as tracking activity changes via electronic medical records especially among overweight/obese populations unable or unlikely to reach national recommendations.
obesity; physical activity; assessment; psychometrics; sensitivity to change
Social support could be a powerful weight-loss treatment moderator or mediator but is rarely assessed. We assessed the psychometric properties, initial levels, and predictive validity of a measure of perceived social support and sabotage from friends and family for healthy eating and physical activity (eight subscales). Overweight/obese women randomized to one of two 6-month, group-based behavioral weight-loss programs (N=267; mean BMI 32.1±3.5; 66.3% White) completed subscales at baseline, and weight loss was assessed at 6 months. Internal consistency, discriminant validity, and content validity were excellent for support subscales and adequate for sabotage subscales; qualitative responses revealed novel deliberate instances not reflected in current sabotage items. Most women (>75%) “never” or “rarely” experienced support from friends or family. Using non-parametric classification methods, we identified two subscales—support from friends for healthy eating and support from family for physical activity—that predicted three clinically meaningful subgroups who ranged in likelihood of losing ≥5% of initial weight at 6 months. Women who “never” experienced family support were least likely to lose weight (45.7% lost weight) whereas women who experienced both frequent friend and family support were more likely to lose weight (71.6% lost weight). Paradoxically, women who “never” experienced friend support were most likely to lose weight (80.0% lost weight), perhaps because the group-based programs provided support lacking from friendships. Psychometrics for support subscales were excellent; initial support was rare; and the differential roles of friend versus family support could inform future targeted weight-loss interventions to subgroups at risk.
Obesity; social support; weight loss; obesity treatment; research methodology; psychometrics
To examine the contributions of frequency, consistency, and comprehensiveness of dietary self-monitoring to long-term weight change.
Design and Methods
Participants included 220 obese women (mean±SD, age=59.3±6.1 years; BMI=36.8±4.9 kg/m2) who achieved a mean loss of -10.39±5.28% from baseline during 6 months of behavioral treatment and regained 2.30±7.28% during a 12-month extended-care period. The contributions of cumulative frequency (total number of food records) of self-monitoring, consistency across time (number of weeks with ≥3 records), and comprehensiveness of information recorded were examined as predictors of weight regain in a hierarchical linear regression analysis The mediating role of adherence to daily caloric intake goals was tested using a bootstrapping analysis.
The association between high total frequency of self-monitoring and reduced weight regain was moderated by weekly consistency of self-monitoring, p=.004; increased frequency produced beneficial effects on weight change only when coupled with high consistency (>3 days/week). There was no impact of comprehensiveness on weight change, p>.05. The favorable effect of high frequency/high consistency self-monitoring on weight change was partially mediated by participants’ success in meeting daily caloric intake goals (p< .001).
The combination of high frequency plus high consistency of dietary self-monitoring improves long-term success in weight management.
obesity treatment; weight maintenance; behavior modifications; behavioral strategies; dietary adherence
This 56-week, randomized, placebo-controlled trial examined the efficacy and safety of naltrexone plus bupropion as an adjunct to intensive behavior modification (BMOD). A total of 793 participants (BMI = 36.5 ± 4.2 kg/m2) was randomly assigned in a 1:3 ratio to: (i) placebo + BMOD (N = 202); or (ii) naltrexone sustained-release (SR, 32 mg/day), combined with bupropion SR (360 mg/day) plus BMOD (i.e., NB32 + BMOD; N = 591). Both groups were prescribed an energy-reduced diet and 28 group BMOD sessions. Co-primary end points were percentage change in weight and the proportion of participants who lost ≥5% weight at week 56. Efficacy analyses were performed on a modified intent-to-treat population (ITT; i.e., participants with ≥1 postbaseline weight while taking study drug (placebo + BMOD, N = 193; NB32 + BMOD, N = 482)). Missing data were replaced with the last observation obtained on study drug. At week 56, weight loss was 5.1 ± 0.6% with placebo + BMOD vs. 9.3 ± 0.4% with NB32 + BMOD (P < 0.001). A completers analysis revealed weight losses of 7.3 ± 0.9% (N = 106) vs. 11.5 ± 0.6% (N = 301), respectively (P < 0.001). A third analysis, which included all randomized participants, yielded losses of 4.9 ± 0.6 vs. 7.8 ± 0.4%, respectively (P < 0.001). Significantly more NB32 + BMOD- vs. placebo + BMOD-treated participants lost ≥5 and ≥10% of initial weight, and the former had significantly greater improvements in markers of cardiometabolic disease risk. NB32 + BMOD was generally well tolerated, although associated with more reports of nausea than placebo + BMOD. The present findings support the efficacy of combined naltrexone/bupropion therapy as an adjunct to intensive BMOD for obesity.
Although behavioral weight-loss interventions produce short-term weight loss, long-term maintenance remains elusive. This randomized trial examined whether learning a novel set of “stability skills” before losing weight improved long-term weight management. Stability skills were designed to optimize individuals’ current satisfaction with lifestyle and self-regulatory habits while requiring the minimum effort and attention necessary.
Overweight/obese women (N = 267) were randomly assigned to one of two 6-month interventions and assessed at baseline, 6, 12, and 18 months. Maintenance First women participated first in an 8-week stability skills maintenance module, then in a standard 20-week behavioral weight-loss program. Weight Loss First women participated first in a standard 20-week behavioral weight-loss program, then in a standard 8-week problem-solving skills maintenance module. There was no intervention staff contact during the 12-month follow-up (6–18 months).
As designed, Maintenance First participants lost the same percent of initial weight during the 6-month intervention period as Weight Loss First participants (M = −8.6%, SD = 5.7 vs. M = −9.1%, SD = 6.9, t = −0.6, p = .52). However, Maintenance First participants regained significantly less weight during the 12-month follow-up (6–18 months) than Weight Loss First participants (M = 3.2 lbs, SD = 10.4 vs. M = 7.3 lbs, SD = 9.9, t = 3.3, p = .001, d = 0.4).
Learning stability skills before losing weight was successful for maintaining weight loss without intervention staff contact during follow-up. These results can inform the study design of future innovative interventions. Trial Registration: ClinicalTrials.gov-NCT00626457.
Obesity; weight loss; weight maintenance; long-term; weight stability; randomized trial
Limitations in mobility are common among older adults with cardiovascular and cardiometabolic disorders and have profound effects on health and well-being. With the growing population of older adults in the United States, effective and scalable public health approaches are needed to address this problem. Our goal was to determine the effects of a physical activity and weight loss intervention on 18-month change in mobility among overweight or obese older adults in poor cardiovascular health.
The study design was a translational, randomized controlled trial of physical activity (PA) and weight loss (WL) on mobility in overweight or obese older adults with cardiovascular disease (CVD) or at risk for CVD. The study was conducted within the community infrastructure of Cooperative Extension Centers. Participants were randomized to 1 of 3 interventions: PA, WL+PA, or a successful aging (SA) education control arm. The primary outcome was time to complete a 400-m walk in seconds (400MWT).
A significant treatment effect (P=.002) and follow-up testing revealed that the WL+PA group improved their 400MWT (adjusted mean [SE], 323.3 [3.7] seconds) compared with both PA (336.3 [3.9] seconds; P=.02) and SA (341.3 [3.9] seconds; P<.001). Participants with poorer mobility at baseline benefited the most (P<.001).
Existing community infrastructures can be effective in delivering lifestyle interventions to enhance mobility in older adults in poor cardiovascular health with deficits in mobility; attention should be given to intervening on both weight and sedentary behavior since weight loss is critical to long-term improvement in mobility.
Obesity is a risk factor for breast cancer recurrence and death. Women who reside in rural areas have higher obesity prevalence and suffer from breast cancer treatment-related disparities compared to urban women. The objective of this 5-year randomized controlled trial is to compare methods for delivering extended care for weight loss maintenance among rural breast cancer survivors. Group phone-based counseling via conference calls addresses access barriers, is more cost-effective than individual phone counseling, and provides group support which may be ideal for rural breast cancer survivors who are more likely to have unmet support needs. Women (n = 210) diagnosed with Stage 0 to III breast cancer in the past 10 years who are ≥ 3 months out from initial cancer treatments, have a BMI 27–45 kg/m2, and have physician clearance were enrolled from multiple cancer centers. During Phase I (months 0 to 6), all women receive a behavioral weight loss intervention delivered through group phone sessions. Women who successfully lose 5% of weight enter Phase II (months 6 to 18) and are randomized to one of two extended care arms: continued group phone-based treatment or a mail-based newsletter. During Phase III, no contact is made (months 18 to 24). The primary outcome is weight loss maintenance from 6 to 18 months. Secondary outcomes include quality of life, serum biomarkers, and cost-effectiveness. This study will provide essential information in how to reach rural survivors in future efforts to establish weight loss support for breast cancer survivors as a standard of care.
breast cancer; obesity; behavioral weight control; rural; quality of life
The current study examined racial/ethnic differences in patterns of weight loss and regain in response to an initial behavioral weight loss intervention followed by an extended-care maintenance program.
We analyzed data from 224 women (African-American n = 43, Caucasian n = 181) from rural communities who participated in an initial 6-month lifestyle intervention for obesity and were then randomized to a face-to-face, telephone, or educational/control extended-care condition.
African-American participants lost less weight during the initial phase of treatment than Caucasian participants (mean ± SE = −6.8 ± .80 vs. −10.7 ± .38 kg, respectively, p = .003). Investigating weight change during month 6 to month 18, we found a significant interaction between race/ethnicity and the provision of an extended-care program. Caucasian participants randomized to either of two extended-care programs regained less weight than those assigned to the control condition (1.2 ± .58 and 4.2 ± .79 kg, respectively, p = .003), but the provision of extended care did not influence weight regain among African-American participants (1.9 ± 1.12 and 1.34 ± 2.04 kg, respectively, p = .815).
Collectively, these findings suggest that although African-American participants lost less weight during the initial phase of treatment, they exhibited better long-term weight-loss maintenance than Caucasian participants. Further, while the provision of extended care successfully enhanced weight maintenance among Caucasian participants, African-American participants maintained their initial weight losses regardless of extended care.
Weight Loss; Weight Regain; Race; Racial Difference; Lifestyle Intervention
Rural counties in the U.S. have higher rates of obesity, sedentary lifestyle, and associated chronic diseases than non-rural areas, yet the management of obesity in rural communities has received little attention from researchers.
To compare 2 extended-care programs for weight management with an education control group.
Design, Setting, and Participants
234 obese women from rural communities who completed an initial 6-month weight-loss program were randomized to extended-care, delivered via telephone counseling or face-to-face sessions, or to an education control group. Cooperative Extension Service offices in six medically underserved rural counties served as venues for the trial. The study was conducted from June 2003 to May 2007.
The extended-care programs entailed problem-solving counseling delivered in 26 biweekly sessions. Control group participants received 26 biweekly newsletters containing weight-control advice.
Main Outcome Measure
Change in weight from randomization.
Mean weight at study entry was 96.4 kg. Mean weight loss during the initial 6-month intervention was 10.0 kg. One year after randomization, participants in the telephone and face-to-face conditions regained less weight (means ± SE = 1.3 ± 0.7 and 1.2 ± 0.6 kg, respectively) than those in the education control group (3.7 ± 0.6 kg; Ps = 0.02 and 0.03). The beneficial effects of extended-care counseling were mediated by greater adherence to behavioral weight-management strategies, and cost analyses indicated that telephone counseling was less expensive than face-to-face intervention.
Extended care delivered either by telephone or face-to-face sessions improved the one-year maintenance of lost weight compared to education alone. Telephone counseling constitutes an effective and cost-efficient option for long-term weight management. Delivering lifestyle interventions via the existing infrastructure of the Cooperative Extension Service represents a viable means of research translation into rural communities with limited access to preventive health services.
ClinicalTrials.gov number, NCT00201006.
To determine if self-reported cynical hostility predicted incident diabetes or increase in number of symptoms associated with metabolic syndrome in postmenopausal women.
Prospective study of a subsample of women (n = 3,658) participating in the Women's Health Initiative Clinical Trial.
Subjects: Postmenopausal women aged 50 to 79 years at baseline who were enrolled in the Women's Health Initiative Dietary Modification Trial, Hormone Trial or both. Measures: The Cynicism subscale of the Cook-Medley Hostility Questionnaire was used to assess cynical hostility at baseline. Incident diabetes was ascertained by self-report of treatment with insulin or oral hypoglycemic medication at one year. Metabolic syndrome was defined based on number of Adult Treatment Panel (ATP) III criteria met at one year. Statistical Analysis: The relationship between baseline cynical hostility and incident diabetes and worsening of metabolic syndrome was assessed from baseline to one year using multivariable Cox proportional hazards models and multivariable logistic regression models, respectively.
Incident diabetes was 36% higher among women in the upper tertile for baseline cynical hostility compared to the lowest tertile (p-trend = 0.05). The odds of a worsening of metabolic syndrome was 27% greater in the highest cynical hostility tertile compared to the lowest tertile (p-trend = 0.04).
Cynical hostility may increase the risk for developing diabetes and worsening of the metabolic syndrome in postmenopausal women.
Diabetes; Metabolic syndrome; Mood; Cynicism; Cynical hostility; Postmenopausal women
Accumulating evidence suggests that both dietary restriction and exercise (DR + E) should be incorporated in weight loss interventions to treat obese, older adults. However, more information is needed on the effects to lower extremity tissue composition—an important consideration for preserving mobility in older adults.
Twenty-seven sedentary women (body mass index: 36.3±5.4kg/m2; age: 63.6±5.6 yrs) were randomly assigned to 6 months of DR + E or a health education control group. Thigh and calf muscle, subcutaneous adipose tissue (SAT), and intermuscular adipose tissue (IMAT) size were determined using magnetic resonance imaging. Physical function was measured using a long-distance corridor walk and knee extension strength.
Compared with control, DR + E significantly reduced body mass (-6.6±3.7kg vs control: -0.05±3.5kg; p < .01). Thigh and calf muscle volumes responded similarly between groups. Within the DR + E group, adipose tissue was reduced more in the thigh than in the calf (p < .04). Knee extension strength was unaltered by DR + E, but a trend toward increased walking speed was observed in the DR + E group (p = .09). Post hoc analyses showed that reductions in SAT and IMAT within the calf, but not the thigh, were associated with faster walking speed achieved with DR + E (SAT: r = -0.62; p = .01; IMAT: r = -0.62; p = .01).
DR + E preserved lower extremity muscle size and function and reduced regional lower extremity adipose tissue. Although the magnitude of reduction in adipose tissue was greater in the thigh than the calf region, post hoc analyses demonstrated that reductions in calf SAT and IMAT were associated with positive adaptations in physical function.
Body composition; Weight loss; Obesity; Aging; Disability.
A key issue in the treatment of obesity in older adults is whether the health benefits of weight loss outweigh the potential risks with respect to musculoskeletal injury.
To compare change in weight, improvements in metabolic risk factors, and reported musculoskeletal adverse events in middle-aged (50–59 years) and older (65–74 years), obese women.
Materials and methods
Participants completed an initial 6-month lifestyle intervention for weight loss, comprised of weekly group sessions, followed by 12 months of extended care with biweekly contacts. Weight and fasting blood samples were assessed at baseline, month 6, and month 18; data regarding adverse events were collected throughout the duration of the study.
Both middle-aged (n = 162) and older (n = 56) women achieved significant weight reductions from baseline to month 6 (10.1 ± 0.68 kg and 9.3 ± 0.76 kg, respectively) and maintained a large proportion of their losses at month 18 (7.6 ± 0.87 kg and 7.6 ± 1.3 kg, respectively); there were no significant differences between the two groups with respect to weight change. Older women further experienced significant reductions in systolic blood pressure, HbA1c, and C-reactive protein from baseline to month 6 and maintained these improvements at month 18. Despite potential safety concerns, we found that older women were no more likely to experience musculoskeletal adverse events during the intervention as compared with their middle-aged counterparts.
These results suggest that older, obese women can experience significant health benefits from lifestyle treatment for obesity, including weight loss and improvements in disease risk factors. Further investigation of the impact of weight loss on additional health-related parameters and risks (eg, body composition, muscular strength, physical functioning, and injuries) in older adults is needed.
lifestyle intervention; adverse events; metabolic risk factors
To examine associations between modifications in parent feeding practices, child diet, and child weight status after treatment and to evaluate dietary mediators.
Design and Methods
Children classified as overweight or obese and 7-11 years old (N=170) completed a 16-session family-based behavioral treatment program (FBT). Anthropometrics (standardized body mass index (zBMI)), Child Feeding Questionnaire, and 24-hr dietary recalls were collected at baseline and post-FBT. Linear regression predicted child zBMI change. Single and multiple mediation tested child dietary modifications as mediators between change in parent feeding practices and child zBMI.
Restrictive parent feeding practices significantly decreased during FBT. Reductions in parent restriction, child weight concern, child total energy intake, and percent energy from fat, and increases in parent perceived responsibility, and child percent energy from protein, predicted reductions in child zBMI. Change in child total energy intake mediated the relation between parent restriction and child zBMI change after accounting for covariates and additional dietary mediators.
FBT is associated with a decrease in parental restriction, which is associated with reductions in child relative weight, which was mediated by a decrease in child energy intake. Teaching parents to reduce children's energy intake without being overly restrictive may improve child weight.
childhood obesity; parents; eating behaviors; weight loss
Behavioral interventions for obesity are commonly delivered in groups, although the effect of group size on weight loss has not been empirically evaluated. This behavioral weight loss trial compared the 6- and 12-month weight changes associated with interventions delivered in a large group (LG) or small groups (SG).
Obese adults (N = 66; mean age = 50 years; mean BMI = 36.5 kg/m2; 47% African American; 86% women) recruited from a health maintenance organization were randomly assigned to: 1) LG treatment (30 members/group), or 2) SG treatment (12 members/group). Conditions were comparable in frequency and duration of treatment, which included 24 weekly group sessions (months 1–6) followed by six monthly extended care contacts (months 7–12). A mixed effects model with unstructured covariance matrix was applied to analyze the primary outcome of weight change while accounting for baseline weight and dependence among participants’ measurements over time.
SG participants lost significantly more weight than LG participants at Month 6 (−6.5 vs. -3.2 kg; p = 0.03) and Month 12 (−7.0 vs. -1.7 kg; p < 0.002). SG participants reported better treatment engagement and self-monitoring adherence at Months 6 and 12, ps < 0.04, with adherence fully mediating the relationship between group size and weight loss.
Receiving obesity treatment in smaller groups may promote greater weight loss and weight loss maintenance. This effect may be due to improved adherence facilitated by SG interactions. These novel findings suggest that the perceived efficiency of delivering behavioral weight loss treatment to LGs should be balanced against the potentially better outcomes achieved by a SG approach.
Weight loss; Group size; Lifestyle intervention; Randomized trial
The 2007 American College of Sports Medicine (ACSM) and the American Heart Association (AHA) physical activity guidelines recommend adults engage in either 150 minutes of moderate intensity or 60 minutes of vigorous intensity physical activity per week to derive health benefits.
In a 6-month clinical trial, we examined whether walking programs of moderate (leisurely-paced) and vigorous (fast-paced) intensity produced improvements in cardiorespiratory fitness as predicted by the ACSM/AHA guidelines.
Participants (N = 155) were instructed to walk 30 minutes per day on 5 or more days per week, at either a moderate or vigorous intensity level (45–55% or 65–75% of maximum heart rate reserve [HRres ], respectively). Within each condition, we categorized participants based on their mean weekly amounts of exercise as reflected in written self-monitoring logs. Fitness was assessed by a maximal graded exercise test at pre- and post-treatment. This trial was conducted in Gainesville, FL between 1999 and 2003.
Mean minutes of walking were related to changes in cardiorespiratory fitness in the vigorous (r = .47; p = < .001) but not moderate intensity condition (r = .07; p = .52). Within the vigorous intensity condition, significantly greater improvements in fitness were achieved by participants with high and medium amounts of accumulated exercise compared with those with low amounts of exercise.
Clinically meaningful improvements in cardiorespiratory fitness were observed in participants who walked a minimum of 60 minutes per week at a fast-pace but not those who walked at a leisurely-pace. These findings support the 2007 ACSM/AHA physical activity recommendations regarding vigorous, but not moderate, intensity physical activity for cardiorespiratory fitness.
walking; exercise intensity; intensity; fitness; physical activity; physical activity guidelines
Few investigations of successful long-term weight loss beyond two years have been conducted, and none has examined weight changes in medically underserved rural populations of older adults. The purpose of this study was to assess long-term weight loss maintenance 3.5 years after the completion of an initial six-month lifestyle intervention for obesity among women aged 50–75 years residing in rural communities.
One hundred and ten obese women with a mean (± standard deviation) age of 60.08 ± 6.17 years and mean body mass index of 36.76 ± 5.10 kg/m2 completed an in-person assessment during which their weight and adherence to behavioral weight management strategies were evaluated.
Participants showed a mean weight reduction of 10.17% ± 5.0% during the initial six- month intervention and regained 6.95% ± 9.44% from the completion of treatment to follow-up assessment 3.5 years later. A substantial proportion of participants (41.80%) were able to maintain weight reductions of 5% or greater from baseline to follow-up. “Successful” participants (those who maintained losses of 5% or greater at follow-up) reported weighing themselves, self-monitoring their intake and calories, planning meals in advance, and choosing lower calorie foods with greater frequency than “unsuccessful” participants (those who lost less than 5%).
Collectively, these findings indicate that a large proportion of participants were able to maintain clinically significant weight losses for multiple years after treatment, and that self-monitoring was a key component of successful long-term weight management.
obesity; weight loss; weight maintenance; lifestyle intervention; rural; health disparities
We propose a nonparametric Bayesian approach to estimate the natural direct and indirect effects through a mediator in the setting of a continuous mediator and a binary response. Several conditional independence assumptions are introduced (with corresponding sensitivity parameters) to make these effects identifiable from the observed data. We suggest strategies for eliciting sensitivity parameters and conduct simulations to assess violations to the assumptions. This approach is used to assess mediation in a recent weight management clinical trial.
This study examined whether improvements in problem-solving abilities mediate the relation between treatment adherence and weight-loss outcome in the behavioral treatment of obesity.
272 women (mean ± SD age = 59.4 ± 6.2 years, BMI = 36.5 ± 4.8) participated in a 6-month lifestyle intervention for obesity. Body weight and problem-solving skills (as measured by the Social Problem Solving Inventory—Revised) were assessed pre- and posttreatment. The completion of self-monitoring logs during the intervention served as the marker of treatment adherence.
At posttreatment, participants lost 8.4 ± 5.8 kg, an 8.8% reduction in body weight. Changes in weight were associated with increased problem-solving skills and with higher levels of treatment adherence. Improvements in problem-solving skills partially mediated the relation between treatment adherence and weight-loss outcome. Moreover, participants with weight reductions > 10% demonstrated significantly greater improvements in problem-solving skills than those with reductions < 5%.
Improvements in problem-solving skills may enable participants to overcome barriers to adherence and thereby enhance treatment-induced weight losses.
Obesity; Weight Loss; Problem-Solving; Adherence; Self-Monitoring
The relative contribution of obesity versus poor fitness to adverse health outcomes and diminished quality of life remains an area of controversy. Indeed, some researchers contend that poor cardiorespiratory fitness represents a greater threat to health and health-related quality of life than excess body weight. We addressed this issue by providing 298 obese 50–75 year-old women with a six-month lifestyle intervention that incorporated a low-calorie eating pattern coupled with an aerobic exercise program consisting of 30 min/day of brisk walking. The results showed that weight loss exhibited a significant individual contribution to improvements in seven of the nine domains of quality of life assessed by the Medical Outcomes Study Short Form (SF-36). With the exception of physical functioning, however, physical fitness did not significantly contribute to improvements beyond the effects weight loss. Moreover, weight loss functioned as a full mediator of the association between increases in physical fitness and improvements in general health, vitality, and change in health relative to the previous year. Collectively, these findings suggest that for treatment-seeking obese individuals, weight loss rather than increased fitness contributes significantly to improvements in health-realted quality of life.
Obesity; Health Related Quality of Life; Physical Fitness; Weight Loss
Rural residents have higher rates of chronic diseases compared to their urban counterparts, and obesity may be a major contributor to this disparity. This study is the first analysis of obesity prevalence in rural and urban adults using body mass index classification with measured height and weight. In addition, demographic, diet, and physical activity correlates of obesity across rural and urban residence are examined.
Analysis of body mass index (BMI), diet, and physical activity from 7,325 urban and 1,490 rural adults in the 2005–2008 National Health and Nutrition Examination Survey (NHANES).
The obesity prevalence was 39.6% (SE = 1.5) among rural adults compared to 33.4% (SE = 1.1) among urban adults (P = .006). Prevalence of obesity remained significantly higher among rural compared to urban adults controlling for demographic, diet, and physical activity variables (odds ratio = 1.18, P = .03). Race/ethnicity and percent kcal from fat were significant correlates of obesity among both rural and urban adults. Being married was associated with obesity only among rural residents, whereas older age, less education, and being inactive was associated with obesity only among urban residents.
Obesity is markedly higher among adults from rural versus urban areas of the United States, with estimates that are much higher than the rates suggested by studies with self-reported data. Obesity deserves greater attention in rural America.
epidemiology; health disparities; obesity; rural; social determinants of health
To compare the costs of parent-only and family-based group interventions for childhood obesity delivered through Cooperative Extension Services in rural communities.
Ninety-three ovenueight or obese children (aged 8 to 14 years) and their parent(s) participated in this randomized controlled trial, which included a 4-month intervention and 6-month follow-up. Families were randomized to either a behavioral family-based intervention (n = 33), a behavioral parent-only intervention (n = 34), or a waitlist control condition (n = 26). Only program costs data for the parent-only and family-based programs are reported here (n = 67). Assessments were completed at baseline, post-treatment (month 4) and follow-up (month 10). The primary outcome measures were total program costs and cost per child for the parent-only and family interventions.
Twenty-six families in the parent-only intervention and 24 families in the family intervention completed all 3 assessments. As reported previously, both intervention programs led to significantly greater decreases in weight status relative to the control condition at month 10 follow-up. There was no significant difference in weight status change between the parent-only and family interventions. Total program costs for the parent-only and family interventions were $13,546 and $20,928, respectively. Total cost per child for the parent-only and family interventions were $521 and $872, respectively.
Parent-only interventions may be a cost-effective alternative treatment for pediatric obesity, especially for families in medically underserved settings.