6-month Weight Loss Research Articles

Neighborhood factors and six-month weight change among overweight individuals in a weight loss intervention.

The purpose of this study was to examine the neighborhood environment and the association with weight change among overweight/obese individuals in the first six months of a 12-month weight loss intervention, EMPOWER, from 2011 to 2015. Measures of the neighborhood environment included neighborhood racial composition, neighborhood income, and neighborhood food retail stores density (e.g., grocery stores). Weight was measured at baseline and 6 months and calculated as the percent weight change from baseline to 6 months. The analytic sample (N = 127) was 91% female and 81% white with a mean age of 51 (± 10.4) years. At 6 months, the mean weight loss was 8.0 kg (± 5.7), which was equivalent to 8.8% (± 6%) of baseline weight. Participants living in neighborhoods in which 25–75% of the residents identified as black had the greatest percentage of weight loss compared to those living in neighborhoods with < 25% or > 75% black residents. No other neighborhood measures were associated with weight loss. Future studies testing individual-level behavioral weight loss interventions need to consider the influence of neighborhood factors, and how neighborhood-level interventions could be enhanced with individual-level interventions that address behaviors and lifestyle changes.

Acceptance-based versus standard behavioral treatment for obesity: Results from the mind your health randomized controlled trial.

To evaluate the efficacy, as well as potential moderators and mediators, of a revised acceptance-based behavioral treatment (ABT) for obesity, relative to standard behavioral treatment (SBT). Participants with overweight and obesity (n = 190) were randomized to 25 sessions of ABT or SBT over 1 year. Primary outcome (weight), mediator, and moderator measurements were taken at baseline, 6 months, and/or 12 months, and weight was also measured every session. Participants assigned to ABT attained a significantly greater 12-month weight loss (13.3% ± 0.83%) than did those assigned to SBT (9.8% ± 0.87%; P = 0.005). A condition by quadratic time effect on session-by-session weights (P = 0.01) indicated that SBT had a shallower trajectory of weight loss followed by an upward deflection. ABT participants were also more likely to maintain a 10% weight loss at 12 months (64.0% vs. 48.9%; P = 0.04). No evidence of moderation was found. Results supported the mediating role of autonomous motivation and psychological acceptance of food-related urges. Behavioral weight loss outcomes can be improved by integrating self-regulation skills that are reflected in acceptance-based treatment, i.e., tolerating discomfort and reduction in pleasure, enacting commitment to valued behavior, and being mindfully aware during moments of decision-making.

MILEPOST Multicenter Randomized Controlled Trial: 12-Month Weight Loss and Satiety Outcomes After pose SM vs. Medical Therapy.

Pose SM is an endolumenal weight-loss intervention in which suture anchors are placed endoscopically in the gastric fundus/distal gastric body. Observational studies of pose have shown safe, effective weight loss. Twelve-month results of a randomized controlled trial comparing weight loss and satiety after pose vs. conventional medical therapy are reported. Subjects with classes I-II obesity were randomized in a 3:1 ratio to pose or diet/exercise guidance only (control). Pose subjects received gastric fundus and distal body suture-anchor plications with diet/exercise counseling. Total body (%TBWL) and excess weight loss (%EWL) were assessed at 6 and 12months. Analysis of covariance (ANCOVA) was used to analyze 12-month %TBWL. Satiety changes were assessed at 6 and 12months. From November 2013 to July 2014, 44 subjects were randomized (34, 77.3% female; mean age, 38.3±10.7years; body mass index, 36.5±3.4kg/m2) to pose (n=34) or control (n=10) groups in three centers. Mean pose procedure time was 51.8±14.5min; pose subjects received a mean 8.8±1.3 fundal and 4.2±0.7 distal body plications. Twelve-month TBWL: pose, 13.0% (EWL, 45.0%), n=30 vs. control group, 5.3% (18.1%), n=9; significant mean difference, 7.7% (95% CI 2.2, 13.2; p<0.01). Pose subjects showed significant reductions in satiety parameters (p<0.001); controls experienced reduced caloric intake and satiety volume (p<0.05). No serious device- or procedure-related adverse events occurred. In a randomized controlled trial at 12months, pose-treated subjects had significantly greater weight loss than those treated with diet/exercise guidance alone. At 6 and 12months, pose subjects showed significant reduction in satiety parameters. clinicaltrials.gov identifier # NCT01843231.

Efficacy of First-Time Intragastric Balloon in Weight Loss: a Systematic Review and Meta-analysis of Randomized Controlled Trials.

The intragastric balloon (IGB) is an adjunctive treatment for obesity. This meta-analysis aimed to evaluate the efficacy and safety of IGB treatment by reviewing randomized controlled trials (RCTs). A total of 20 RCTs involving 1195 patients were identified. Weight loss results before and after 3months were analyzed separately. The weight loss results of patients with and without IGB treatment were compared. Our meta-analysis calculated the following significant effect sizes: 1.59 and 1.34kg/m2 for overall and 3-month BMI loss, respectively; 14.25 and 11.16% for overall and >3-month percentage of excess weight loss, respectively; 4.6 and 4.77kg for overall and 3-month weight loss, respectively; and 2.81, 1.62, and 4.09% for overall, 3-month, and >3-month percent of weight loss, respectively. A significant effect size was calculated that favored fluid-filled IGBs over air-filled IGBs. Flatulence (8.75 vs. 3.89%, p=0.0006), abdominal fullness (6.32 vs. 0.55%, p=0.001), abdominal pain (13.86 vs. 7.2%, p=0.0001), abdominal discomfort (4.37 vs. 0.55%, p=0.006), and gastric ulcer (12.5 vs. 1.2%, p<0.0001) were significantly more prevalent among IGB patients than among non-IGB control patients. No mortality was reported from IGB treatment. IGB treatment, in addition to lifestyle modification, is an effective short-term modality for weight loss. However, there is not sufficient evidence confirming its safety or long-term efficacy.

Intermuscular adipose tissue and thigh muscle area dynamics during an 18-month randomized weight loss trial

It remains unclear whether intermuscular adipose tissue (IMAT) has any metabolic influence or whether it is merely a marker of abnormalities, as well as what are the effects of specific lifestyle strategies for weight loss on the dynamics of both IMAT and thigh muscle area (TMA). We followed the trajectory of IMAT and TMA during 18-mo lifestyle intervention among 278 sedentary participants with abdominal obesity, using magnetic resonance imaging. We measured the resting metabolic rate (RMR) by an indirect calorimeter. Among 273 eligible participants (47.8 ± 9.3 yr of age), the mean IMAT was 9.6 ± 4.6 cm(2) Baseline IMAT levels were directly correlated with waist circumference, abdominal subdepots, C-reactive protein, and leptin and inversely correlated with baseline TMA and creatinine (P < 0.05 for all). After 18 mo (86.3% adherence), both IMAT (-1.6%) and TMA (-3.3%) significantly decreased (P < 0.01 vs. baseline). The changes in both IMAT and TMA were similar across the lifestyle intervention groups and directly corresponded with moderate weight loss (P < 0.001). IMAT change did not remain independently associated with decreased abdominal subdepots or improved cardiometabolic parameters after adjustments for age, sex, and 18-mo weight loss. In similar models, 18-mo TMA loss remained associated with decreased RMR, decreased activity, and with increased fasting glucose levels and IMAT (P < 0.05 for all). Unlike other fat depots, IMAT may not represent a unique or specific adipose tissue, instead largely reflecting body weight change per se. Moderate weight loss induced a significant decrease in thigh muscle area, suggesting the importance of resistance training to accompany weight loss programs.

A Test of Social Cognitive Theory to Explain Men's Physical Activity During a Gender-Tailored Weight Loss Program.

Physical inactivity is a leading contributor to the burden of disease in men. Social-cognitive theories may improve physical activity (PA) interventions by identifying which variables to target to maximize intervention impact. This study tested the utility of Bandura's social cognitive theory (SCT) to explain men's PA during a 3-month weight loss program. Participants were 204 overweight/obese men (M [SD] age = 46.6 [11.3] years; body mass index = 33.1 [3.5] kg/m2). A longitudinal, latent variable structural equation model tested the associations between SCT constructs (i.e., self-efficacy, outcome expectations, intention, and social support) and self-reported moderate-to-vigorous PA (MVPA) and examined the total PA variance explained by SCT. After controlling for Time 1 cognitions and behavior, the model fit the data well (χ2 = 73.9, degrees of freedom = 39, p < .001; normed χ2 = 1.9; comparative fit index = 0.96; standardized root mean residual = 0.059) and explained 65% of the variance in MVPA at Time 2. At Time 2, self-efficacy demonstrated the largest direct and total effects on MVPA (βdirect = .45, p < .001; βtotal = .67, p = .002). A small-to-medium effect was observed from intention to MVPA, but not from outcome expectations or social support. This study provides some evidence supporting the tenets of SCT when examining PA behavior in overweight and obese men. Future PA and weight loss interventions for men may benefit by targeting self-efficacy and intention, but the utility of targeting social support and outcome expectations requires further examination.

The Effect of Self-Efficacy on Behavior and Weight in a Behavioral Weight-Loss Intervention.

To determine whether eating self-efficacy (ESE) and physical activity self-efficacy (PASE) are predictive of dietary intake, physical activity, and weight change within a behavioral weight-loss intervention, and whether dietary intake and physical activity mediate relationships between self-efficacy and weight change. The study sample included 246 participants from a randomized trial with complete data on study variables at 12 months. ESE, PASE, calories consumed, minutes of moderate-to-vigorous physical activity (MVPA), and weight were measured at baseline, 6, and 12 months. ESE at baseline was associated with 12-month percent weight loss (PWL), and was mediated by average calories consumed at 6 and 12 months. Change in ESE from baseline to 6 months was associated with calories consumed at 12 months and 12-month percent weight loss, but the mediated relationship was not significant. Baseline PASE was not associated with average MVPA at 6 and 12 months or 12-month PWL, but change in PASE from baseline to 6 months was associated with 12-month PWL through its effect on MVPA at 12 months. Increases in ESE and PASE during the active phase of the intervention are predictive of dietary intake, physical activity and weight loss at later points, but further research should include explorations of the reciprocal relationship between behavior and self-efficacy to better inform intervention strategies that target self-efficacy and promote behavior change. (PsycINFO Database Record

Impact of newer self-monitoring technology and brief phone-based intervention on weight loss: A randomized pilot study.

Despite the proliferation of newer self-monitoring technology (e.g., activity monitors and smartphone apps), their impact on weight loss outside of structured in-person behavioral intervention is unknown. A randomized, controlled pilot study was conducted to examine efficacy of self-monitoring technology, with and without phone-based intervention, on 6-month weight loss in adults with overweight and obesity. Eighty participants were randomized to receive standard self-monitoring tools (ST, n = 26), technology-based self-monitoring tools (TECH, n = 27), or technology-based tools combined with phone-based intervention (TECH + PHONE, n = 27). All participants attended one introductory weight loss session and completed assessments at baseline, 3 months, and 6 months. Weight loss from baseline to 6 months differed significantly between groups P = 0.042; there was a trend for TECH + PHONE (-6.4 ± 1.2 kg) to lose more weight than ST (-1.3 ± 1.2 kg); weight loss in TECH (-4.1 ± 1.4 kg) was between ST and TECH + PHONE. Fewer ST (15%) achieved ≥5% weight losses compared with TECH and TECH + PHONE (44%), P = 0.039. Adherence to self-monitoring caloric intake was higher in TECH + PHONE than TECH or ST, Ps < 0.05. These results suggest use of newer self-monitoring technology plus brief phone-based intervention improves adherence and weight loss compared with traditional self-monitoring tools. Further research should determine cost-effectiveness of adding phone-based intervention when providing self-monitoring technology.

Effects of vitamin D supplementation during weight loss on sex hormones in postmenopausal women.

The aim of the study was to compare the effects of vitamin D3 supplementation versus placebo on serum sex hormones in postmenopausal women completing a 12-month diet + exercise weight loss program. Two hundred eighteen overweight or obese women (50-75 y) with serum 25-hydroxyvitamin D at least 10 to less than 32 ng/mL ("insufficient") were randomized to either weight loss + 2,000 IU/day oral vitamin D3, or to weight loss + daily placebo. Serum sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone were measured by radioimmunoassay before randomization and at 12 months. Mean changes were compared between groups (intent-to-treat) using generalized estimating equations. The 12-month changes in sex hormone-binding globulin, estrone, total, free, and bioavailable estradiol, and testosterone did not differ between groups (all P > 0.05). However, a greater increase in serum 25-hydroxyvitamin D was associated with a greater increase in sex hormone-binding globulin (Ptrend = 0.01), and larger decreases in free and bioavailable estradiol (Ptrend = 0.04, Ptrend = 0.03, respectively). In post-hoc analyses, we compared women randomized to vitamin D whose serum 25-hydroxyvitamin D remained insufficient (n = 38), to women who became replete (25-hydroxyvitamin D ≥32 ng/mL; n = 53). Replete women showed greater reductions in bioavailable estradiol (-1.8 vs -0.7 pg/mL), free testosterone (-0.8 vs -0.3 pg/mL), and bioavailable testosterone (-1.8 vs -0.6 ng/dL), and a greater increase in sex hormone-binding globulin (10.6 vs 4.7 nmol/L) (all P < 0.05), even after adjusting for differences in total 12-month weight loss. Overall, 12-month changes in sex hormone did not differ between groups. However, vitamin D repletion was associated with greater reductions in sex hormones during weight loss, with a possible dose-dependent effect. Future studies should test higher doses and target circulating 25-hydroxyvitamin D levels when measuring such effects.

Mobile Technology for Vegetable Consumption: A Randomized Controlled Pilot Study in Overweight Adults.

BackgroundMobile apps present a potentially cost-effective tool for delivering behavior change interventions at scale, but no known studies have tested the efficacy of apps as a tool to specifically increase vegetable consumption among overweight adults.ObjectiveThe purpose of this pilot study was to assess the initial efficacy and user acceptability of a theory-driven mobile app to increase vegetable consumption.MethodsA total of 17 overweight adults aged 42.0 (SD 7.3) years with a body mass index (BMI) of 32.0 (SD 3.5) kg/m2 were randomized to the use of Vegethon (a fully automated theory-driven mobile app enabling self-monitoring of vegetable consumption, goal setting, feedback, and social comparison) or a wait-listed control condition. All participants were recruited from an ongoing 12-month weight loss trial (parent trial). Researchers who performed data analysis were blinded to condition assignment. The primary outcome measure was daily vegetable consumption, assessed using an adapted version of the validated Harvard Food Frequency Questionnaire administered at baseline and 12 weeks after randomization. An analysis of covariance was used to assess differences in 12-week vegetable consumption between intervention and control conditions, controlling for baseline. App usability and satisfaction were measured via a 21-item post-intervention questionnaire.ResultsUsing intention-to-treat analyses, all enrolled participants (intervention: 8; control: 9) were analyzed. Of the 8 participants randomized to the intervention, 5 downloaded the app and logged their vegetable consumption a mean of 0.7 (SD 0.9) times per day, 2 downloaded the app but did not use it, and 1 never downloaded it. Consumption of vegetables was significantly greater among the intervention versus control condition at the end of the 12-week pilot study (adjusted mean difference: 7.4 servings; 95% CI 1.4-13.5; P=.02). Among secondary outcomes defined a priori, there was significantly greater consumption of green leafy vegetables, cruciferous vegetables, and dark yellow vegetables (adjusted mean difference: 2.6, 1.6, and 0.8 servings; 95% CI 0.1-5.0, 0.1-3.2, and 0.3-1.4; P=.04, P=.04, and P=.004, respectively). Participants reported positive experiences with the app, including strong agreement with the statements “I have found Vegethon easy to use” and “I would recommend Vegethon to a friend” (mean 4.6 (SD 0.6) and 4.2 (SD 0.8), respectively, (on a 5-point scale).ConclusionsVegethon demonstrated initial efficacy and user acceptability. A mobile app intervention may be useful for increasing vegetable consumption among overweight adults. The small sample size prevented precise estimates of effect sizes. Given the improved health outcomes associated with increases in vegetable consumption, these findings indicate the need for larger, longer-term evaluations of Vegethon and similar technologies among overweight adults and other suitable target groups.Trial RegistrationClinicalTrials.gov NCT01826591; https://clinicaltrials.gov/ct2/show/NCT01826591 (Archived by WebCite at http://www.webcitation.org/6hYDw2AOB)

Associations Between Sleep and Changes in Activity and Barriers to Healthy Eating Following a 12-month Behavioral Weight Loss Intervention

Associations Between Sleep and Changes in Activity and Barriers to Healthy Eating Following a 12-month Behavioral Weight Loss Intervention

Intermuscular Adipose Tissue, Muscle Quality and Physical Function Following Weight loss in Overweight Older Women

PURPOSE: Exercise and diet-induced weight loss are recommended to improve physical function in overweight and obese older adults, but the physiologic factors associated with improvements in physical function are unclear. This study examined the effects of exercise and weight loss on thigh composition, muscle quality and physical function, and the relationships between changes in these outcomes, in overweight and obese older women. METHODS: Twenty-five overweight/obese (BMI = 29.0 ± 3.2 kg/m2) postmenopausal (age = 68.5 ± 3.8 y) women completed a 6-month exercise and weight loss intervention designed to facilitate a 10% loss of initial body weight. The intervention was comprised of a) three 75-minute sessions per week that integrated cardiorespiratory, resistance, and balance training and b) recommendations to reduce energy intake by ~500 kcal/d. Whole-body composition was measured via dual-energy X-ray absorptiometry and thigh composition was determined using magnetic resonance imaging. Muscle quality (N-m/cm2) was defined as isokinetic knee torque divided by thigh muscle cross-sectional area. Physical function was measured using the 6-minute walk and 30-s chair stand. RESULTS: At 6 months, overall weight loss was 7.6 ± 3.1 kg (−9.9 ± 3.9%, p < 0.01). There was a 16.3 ± 8.8% reduction in thigh intermuscular adipose tissue (−2.9 ± 2.0 cm2, p < 0.01) and 18.0 ± 7.7% decrease in subcutaneous adipose tissue (-18.3 ± 8.4 cm2, p < 0.01), while muscle area did not change (-1.0 ± 2.7 cm2, p = 0.12). Muscle quality (+0.11 ± 0.20 N-m/cm2, p < 0.01) and measures of physical function improved (+9.7-58.7%, p < 0.01). Reduction in thigh intermuscular adipose tissue was the strongest independent predictor of a change in performance on the 30-s chair stand (standardized β = −0.80, p < 0.01) accounting for 34% of the variance. In contrast, change in muscle quality was the strongest independent predictor of change in 6-minute walk distance (β = 0.48, p < 0.05) accounting for 24% of the variance. CONCLUSIONS: Changes in intermuscular adipose tissue and muscle quality are both independent predictors of improved physical function following exercise and weight loss in overweight/obese older women; however, their relative importance may vary according to the functional task. Funded in part by The Beef Checkoff: co-PIs; Evans & Johnson

Metformin-Sustained Weight Loss and Reduced Android Fat Tissue At 12 Months In Empowir (Enhance The Metabolic Profile Of Women With Insulin Resistance): A Double Blind, Placebo-Controlled, Randomized Trial of Normoglycemic Women with Midlife Weight Gain

To assess 12-month body weight (BW) and body composition changes in normoglycemic women with midlife weight gain, after dietary and pharmacologic interventions targeting hyperinsulinemia. EMPOWIR (Enhance the Metabolic Profile of Women With Insulin Resistance; NCT00618072) was a double-blind, placebo-controlled, 12-month trial of women with >20-pound weight gain, normal glucose tolerance test, and increased area-under-the-curve insulin. Subjects (mean ± SD, 46.7 ± 6.5 years of age; body mass index, 30.8 ± 2.8 kg/m(2); 50% white) attended 4 nutrition workshops to introduce a novel carbohydrate-modified diet (CMD) and were then randomized to one of three arms for 6 months (phase 1): CMD alone (D), or in combination with metformin (M), or metformin + rosiglitazone (MR), with rerandomization of the D group to one of the active treatment arms (phase 2, months 7 through 12). Repeated measure analysis of variance was used to assess BW at baseline, 6 months, and 12 months in 32 subjects with 12-month data; paired t tests compared baseline and 12-month dual-energy X-ray absorptiometry-derived body composition. Mean (±SD) BW decreased significantly at 12 months in the M arm: 85.1 ± 8.5 kg to 79.8 ± 9.0 kg (P = .0003), with 54% of variance in weight over time explained by M treatment. Mean (±SD) percent android fat decreased significantly in the M and D arms: 53.5 ± 4.8% to 49.3 ± 7.6% (P = .010) and 52.9 ± 6.2% to 48.1 ± 8.7% (P = .021). In combination with a novel carbohydrate modified diet, metformin enhanced 12-month weight loss and improved body composition in ethnically diverse normoglycemic, hyperinsulinemic women with midlife weight gain. These findings suggest that EMPOWIR's easily implemented dietary interventions, alone and in combination with pharmacotherapies that target hyperinsulinemia, merit additional investigation in larger, long-term studies.

A 6-month telephone-based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension.

SummaryObjectivesThe purpose of this paper is to measure the change in body weight after a 6‐month telephone‐based weight loss intervention in overweight and obese subjects with idiopathic intracranial hypertension (IIH) and mild visual loss randomized to receive either acetazolamide or placebo.MethodsOne hundred sixty‐five subjects with IIH, aged 29.1 ± 7.5 (mean ± SD) and BMI 39.9 + 8.3 kg/m2, enrolled at 38 academic and private practice sites in North America, participated in this trial. This was a randomized, double‐masked, placebo‐controlled trial of acetazolamide in subjects with IIH and mild visual loss. All participants received a reduced‐sodium, weight‐reduction diet and a 6‐month telephone‐based weight loss intervention. Six‐month changes from baseline in body weight, perimetric mean deviation as assessed by automated perimetry and quality of life using the National Eye Institute Visual Function Questionnaire 25 and the 36‐item Short Form Health Survey were measured.ResultsMean percent weight change at 6 months was −5.9% ± 6.7% of initial body weight overall, −3.5% ± 5.9% in the placebo group and −7.8% ± 6.8% in the acetazolamide group. Weight change was not associated with changes in either mean deviation or quality of life scores.ConclusionPatients with IIH and mild visual loss assigned to either acetazolamide or placebo, all of whom received a 6‐month telephone‐based weight loss intervention, lost an average of 5.9% of initial body weight, consistent with NHLBI guidelines of 5% to 10% of body weight loss for clinically significant health benefit.

Can early weight loss, eating behaviors and socioeconomic factors predict successful weight loss at 12- and 24-months in adolescents with obesity and insulin resistance participating in a randomised controlled trial?

BackgroundLifestyle interventions in adolescents with obesity can result in weight loss following active intervention but individual responses vary widely. This study aimed to identify predictors of weight loss at 12- and 24-months in adolescents with obesity and clinical features of insulin resistance.MethodsAdolescents (n = 111, 66 girls, aged 10–17 years) were participants in a randomised controlled trial, the RESIST study, examining the effects of two diets differing in macronutrient content on insulin sensitivity. Eighty-five completed the 12-month program and 24-month follow-up data were available for 42 adolescents. Change in weight was determined by BMI expressed as a percentage of the 95th percentile (BMI95). The study physician collected socioeconomic data at baseline. Physical activity and screen time, and psychological dimensions of eating behavior were self-reported using the validated CLASS and EPI-C questionnaires, respectively. Stepwise multiple regressions were conducted to identify models that best predicted change in BMI95 at 12- and 24-months.ResultsMean BMI95 was reduced at 12-months compared with baseline (mean difference [MD] ± SE: -6.9 ± 1.0, P < 0.001) but adolescents had significant re-gain from 12- to 24-months (MD ± SE: 3.7 ± 1.5, P = 0.017). Participants who achieved greater 12-month weight loss had: greater 3-month weight loss, a father with a higher education, lower baseline external eating and parental pressure to eat scores and two parents living at home. Participants who achieved greater 24-month weight loss had: greater 12-month weight loss and a lower baseline emotional eating score.ConclusionsEarly weight loss is consistently identified as a strong predictor of long-term weight loss. This could be because early weight loss identifies those more motivated and engaged individuals. Patients who have baseline factors predictive of long-term weight loss failure may benefit from additional support during the intervention. Additionally, if a patient does not achieve early weight loss, further support or transition to an alternate intervention where they may have increased success may be considered.Trial registrationAustralian New Zealand Clinical Trial Registration Number (ACTRN) 12608000416392 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=83071

Energy intake highs and lows: how much does consistency matter in weight control?

Behavioural weight control programmes recommend adherence to daily energy intake goals, yet also allow for flexibility in intake across days. Evidence is lacking as to whether intake consistency is important for weight control. The current study explored the relation between day-to-day intake consistency and weight loss in the context of behavioural weight loss treatment and examined the relationship between variability in intake and several factors known to be associated with weight control success. Participants (N = 283) enrolled in a 12-month behavioural weight loss programme completed 24-h recalls of dietary intake and psychological measures. At the end of treatment, low intake variability and greater weight loss were associated, but variability was not predictive of weight loss independent of mean intake in continuous analyses. Interestingly, participants who met the programme goal of ≥10% weight loss had less intake variability compared to those who lost <10%, although groups did not differ significantly on mean intake. Results suggest that daily intake consistency may facilitate successful weight loss for some. Additionally, autonomous motivation for weight management and cognitive dietary restraint were inversely related to end-of-treatment intake variability. Additional research is needed to examine whether recommendations to limit intake variability during behavioural weight loss treatment improve long-term weight control.

The impact of continued intervention on weight: Five-year results from the weight loss maintenance trial.

In the Weight Loss Maintenance (WLM) Trial, a personal contact (PC) intervention sustained greater weight loss relative to a self-directed (SD) group over 30 months. This study investigated the effects of continued intervention over an additional 30 months and overall weight change across the entire WLM Trial. WLM had 3 phases. Phase 1 was a 6-month weight loss program. In Phase 2, those who lost ≥4 kg were randomized to a 30-month maintenance trial. In Phase 3, PC participants (n = 196, three sites) were re-randomized to no further intervention (PC-Control) or continued intervention (PC-Active) for 30 more months; 218 SD participants were also followed. During Phase 3, weight increased 1.0 kg in PC-Active and 0.5 kg in PC-Control (mean difference 0.6 kg; 95% CI:-1.4 to 2.7; P = 0.54). Mean weight change over the entire study was -3.2 kg in those originally assigned to PC (PC-Combined) and -1.6 kg in SD (mean difference -1.6 kg; 95% CI:-3.0 to -0.1; P = 0.04). After 30 months of the PC maintenance intervention, continuation for another 30 months provided no additional benefit. However, across the entire study, weight loss was slightly greater in those originally assigned to PC.

Abstract MP92: Changes in Objective and Subjective Sleep Parameters Following a 12-month Behavioral Weight Loss Intervention and Their Relationship to Weight Change

Introduction: Despite increased recognition of the influence of sleep on weight loss, lifestyle interventions have paid little attention to sleep and its change with intervention. Moreover, available evidence on the relevance of sleep in weight loss interventions has been limited to self-reported sleep data. The purpose of these analyses was to examine the influence of a 12-mo behavioral weight loss intervention on objective and subjective sleep parameters and to evaluate whether changes in sleep were related to weight loss. Hypothesis: We hypothesized that objective and subjective sleep measures would improve following the intervention and that improved sleep would be associated with greater weight loss. Methods: A sample of 127 adults (89% female, 84% Caucasian, 51.8±9.7 y, 34.0±4.5 kg/m2) participated in a 12-mo standard behavioral weight loss intervention that included 24 group sessions. Sleep was assessed objectively at baseline and 12 mo with 5-7 days of actigraphy (Philips Actiwatch 2). Measures included total sleep time (total time spent asleep), sleep efficiency (percentage of time asleep while in bed), and the Fragmentation Index (restlessness during sleep). Subjective sleep quality was assessed with the Pittsburgh Sleep Quality Index (PSQI), yielding a global PSQI score (overall sleep quality) and individual PSQI factors (perceived sleep quality, sleep efficiency, daytime disturbance) were evaluated. Weight outcomes included the percentage of baseline weight lost at 12 mo and whether clinically significant weight loss (≥10%) was achieved. Analyses (repeated measures ANOVA, multiple linear regression, and binary logistic regression) were adjusted for age, sex, and race. Results: The mean 12-mo weight loss was 9.1±8.1%, with 43% achieving at least 10% weight loss. No actigraphic sleep measures significantly changed from baseline to 12 mo. Overall sleep quality significantly improved over the 12 mo (6.4±3.6 to 5.9±3.1 [P=.02]), as did the PSQI factors of perceived sleep quality (P=.05) and sleep efficiency (P=.03). Baseline to 12-mo improvements in the Fragmentation Index and PSQI perceived sleep quality were associated with greater weight loss (β=.22 [P=.03] and β=.29 [P&lt;.01]). Blunted improvements in the Fragmentation Index and the PSQI perceived sleep quality factor were associated with reduced odds of achieving at least 10% weight loss (OR=0.89 [P=.02] and OR=0.20 [P&lt;.01]). No other sleep measures were associated with weight loss outcomes. Conclusions: Following a behavioral intervention that resulted in clinically significant weight loss, only subjective sleep quality was improved. However, weight loss was optimized among adults whose sleep fragmentation decreased and sleep quality improved. Whether augmenting behavioral weight loss interventions with sleep-focused content would lead to greater weight loss remains to be determined.

The Influence of Health Literacy on Reach, Retention, and Success in a Worksite Weight Loss Program.

To examine if employee health literacy (HL) status moderated reach, retention, and weight outcomes in a worksite weight loss program. The study was a two-group cluster randomized controlled weight loss trial. The study was conducted in 28 worksites. Subjects comprised 1460 employees with a body mass index >25 kg/m(2). Two 12-month weight loss interventions targeted diet and physical activity behaviors: incentaHEALTH (INCENT; incentivized individually targeted Internet-based intervention) and Livin' My Weigh (LMW; less-intense quarterly newsletters). A validated three-item HL screening measure was self-completed at baseline. Weight was objectively assessed with the Health Spot scale at baseline and 12-month follow-up. The impact of HL on program effectiveness was assessed through fixed-effect parametric models that controlled for individual (i.e., age, gender, race, ethnicity, income, education) and worksite random effects. Enrolled employees had significantly higher HL status [13.54 (1.68)] as compared to unenrolled [13.04 (2.17)] (p < .001). This finding was consistent in both interventions. Also, HL moderated weight loss effects (beta = .66; SE = 027; p = .014) and losing >5% weight (beta = -1.53; SE = .77; p < .047). For those with lower baseline HL, the INCENT intervention produced greater weight loss outcomes compared to LMW. The HL level of employees retained was not significantly different from those lost to follow-up. HL influences reach and moderates weight effects. These findings underscore the need to integrate recruitment strategies and further evaluate programmatic approaches that attend to the needs of low-HL audiences.

Abstract P3-08-01: Randomized controlled trial of weight loss vs. usual care on telomere length in women with breast cancer: The lifestyle, exercise and nutrition (LEAN) study

Abstract PURPOSE: Some studies suggest that telomere shortening due to repeated cell divisions may be associated with increased breast cancer risk and mortality. Obesity is also associated with increased breast cancer risk and mortality. Few studies have examined telomere length as a potential mechanism/biomarker mediating the obesity-breast cancer association. One study published of a diet, physical activity and support intervention in prostate cancer patients found a positive association between lifestyle changes and relative lengthening of telomeres, and another study of weight loss in healthy postmenopausal women observed no effect of weight loss on leukocyte telomere length. The purpose of our study was to examine the effect of a 6-month diet- and exercise-induced weight loss intervention vs. usual care on telomere length in 100 breast cancer survivors. METHODS: 100 breast cancer survivors with BMI≥25 kg/m2 were randomly assigned to a weight loss counseling intervention with either telephone or in-person counseling (n = 67) or usual care group (n=33). Weight loss counseling included eleven 30-minute counseling sessions over 6 months, focusing on reducing caloric intake, increasing physical activity and behavioral therapy. Body composition (height, weight, and DEXA scans), physical activity and diet were measured at baseline and 6-months. Fasting blood samples were also collected at baseline and 6 months. Relative telomere length (T/S: telomere length/single copy of gene albumin) was measured by quantitative-polymerase chain reaction (qPCR) done on buffy coat extracted genomic DNA. Mean baseline to 6-month changes were compared between groups (intent-to-treat) using generalized estimating equations and Pearson correlation coefficients. RESULTS: Baseline characteristics were similar for women randomized to each group. Women were 59±7 years, with BMI 33.1±6.6 kg/m2 and were 2.9±2.1 years from diagnosis; 91% were non-Hispanic white, and 51% were diagnosed with Stage I breast cancer. Average 6-month weight loss was 6.2% and 2.0% for weight loss and usual care groups, respectively (p=0.0004). At baseline, higher % body fat was associated with shorter T/S (r = -0.31, P=0.012). After 6 months, women randomized to weight loss experienced a 4% T/S lengthening compared to a 5% T/S shortening in the usual care group (P=0.10) (Table 1). Effect of weight loss vs. usual care on leukocyte telomere lengthLEAN VariableUsual Care Weight Loss Group TelomereNMeanSDNMeanSDBaseline330.850.26630.750.216 Month Change26-0.040.21540.030.18 (-5%) (+4%)p=.10SD=Standard Deviation CONCLUSION: Our results indicate that higher % body fat is associated with shorter leukocyte telomere length, and weight loss was associated with an increase in leukocyte telomere length, suggesting that telomere length may be a mechanism mediating the relationship between obesity and breast cancer risk and mortality. Citation Format: Sanft T, Lu L, Harrigan M, Cartmel B, Zhou Y, Chagpar A, Pusztai L, Irwin M. Randomized controlled trial of weight loss vs. usual care on telomere length in women with breast cancer: The lifestyle, exercise and nutrition (LEAN) study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-08-01.