Weight Loss Maintenance Trial Research Articles

Weight loss history as a predictor of weight loss: results from Phase I of the weight loss maintenance trial

Weight loss history as a predictor of weight loss: results from Phase I of the weight loss maintenance trial

Sex hormone changes during weight loss and maintenance in overweight and obese postmenopausal African-American and non-African-American women

IntroductionChanges in sex hormones with weight loss might have implications for breast cancer prevention but have not been examined extensively, particularly in African-American (AA) women.MethodsWe conducted a prospective study of 278 overweight/obese postmenopausal women (38% AA) not taking hormone therapy within the Weight Loss Maintenance Trial. All participants lost at least 4 kg after a 6-month weight-loss phase and attempted to maintain weight loss during the subsequent 12 months. We evaluated the percentage changes in estrone, estradiol, free estradiol, testosterone, free testosterone, androstenedione, dehydroepiandrosterone sulfate and sex hormone-binding globulin (SHBG) using generalized estimating equations.ResultsIn all study phases, AA women had higher levels of estrogen and testosterone concentrations, independent of adiposity. On average, participants lost 7.7 kg during the weight-loss phase, and concentrations of estrone (-5.7%, P = 0.006), estradiol (-9.9%, P <0.001), free estradiol (-13.4%, P <0.0001), and free testosterone (-9.9%, P <0.0001) decreased, while the SHBG concentration (16.2%, P <0.001) increased. Weight change did not significantly affect total testosterone or other androgen concentrations. Compared with non-AA women, AA women experienced less change in estrogens per kilogram of weight change (that is, per 1 kg weight loss: estrone, -0.6% vs. -1.2%, P-interaction = 0.10; estradiol, -1.1% vs. -1.9%, P-interaction = 0.04; SHBG, 0.9% vs. 1.6%, P-interaction = 0.006; free estradiol, -1.4% vs. -2.1%, P-interaction = 0.01).ConclusionTo the best of our knowledge this is the first study to examine and compare the effects of intentional weight loss and maintenance on a panel of sex hormones in AA women and non-AA women. Although speculative, these data suggest hormonal differences may contribute to different racial patterns of breast cancer incidence and mortality and encourage further investigations to understand the long-term effects of weight loss on sex hormones in obese postmenopausal women.Trial RegistrationClinicalTrials.gov: NCT00054925

Predictors of Long‐Term Weight Loss in Adults With Modest Initial Weight Loss, by Sex and Race

Effective weight management interventions could reduce race-sex disparities in cardiovascular disease (CVD), yet little is known about factors associated with successful weight loss maintenance in race-sex subgroups. In the Weight Loss Maintenance trial (WLM), overweight/obese (BMI 25-45 kg/m(2)) adults who lost ≥4 kg in a 6-month behavioral weight loss intervention (phase I) were randomized into one of three 30-month maintenance interventions (phase II). To investigate predictors in subgroups, randomized groups were combined for this analysis. Of 1,685 phase I participants, 1,032 (61%) entered phase II, including 12% black men (BM), 26% black women (BW), 25% white men (WM), and 37% white women (WW). Weight change over the 36-month study ranged from -2.3% (95% confidence interval = -3.1 to -1.5%) in BW to -4.5% (95% confidence interval = -5.7 to -4.0%) in WM, the result of differential weight loss during phase I. Within race, men lost significantly more weight than women, but within sex group, weight loss did not differ significantly between races. Although participants regained weight during phase II, regain did not differ by race-sex group, and mean weight at the end of the study was significantly lower than phase I entry weight for each subgroup. In regression models, phase I weight loss predicted overall 36-month weight loss in all race-sex groups. Healthy dietary pattern at entry, improvement in dietary pattern, or both were predictive in three of four race-sex groups. Few other variables other than initial weight loss and dietary pattern were predictive. Future research should identify additional modifiable influences on long-term maintenance after a modest weight loss.

Weight loss history as a predictor of weight loss: results from Phase I of the weight loss maintenance trial

Past studies have suggested that weight loss history is associated with subsequent weight loss. However, questions remain whether method and amount of weight lost in previous attempts impacts current weight loss efforts. This study utilized data from the Weight Loss Maintenance Trial to examine the association between weight loss history and weight loss outcomes in a diverse sample of high-risk individuals. Multivariate regression analysis was conducted to determine which specific aspects of weight loss history predict change in weight during a 6-month weight loss intervention. Greater weight loss was predicted by fewer previous weight loss attempts with assistance (p=0.03), absence of previous dietary/herbal weight loss supplement use (p=0.01), and greater maximum weight loss in previous attempts (p<0.001). Future interventions may benefit from assessment of weight loss history and tailoring of interventions based on past weight loss behaviors and outcomes.

Interactive computer-based interventions for weight loss or weight maintenance in overweight or obese people.

The World Health Organization (WHO) estimates that the number of obese or overweight individuals worldwide will increase to 1.5 billion by 2015. Chronic diseases associated with overweight or obesity include diabetes, heart disease, hypertension and stroke. To assess the effects of interactive computer-based interventions for weight loss or weight maintenance in overweight or obese people. We searched several electronic databases, including CENTRAL, MEDLINE, EMBASE, CINAHL, LILACS and PsycINFO, through 25 May 2011. We also searched clinical trials registries to identify studies. We scanned reference lists of included studies and relevant systematic reviews. Studies were included if they were randomized controlled trials or quasi-randomized controlled trials that evaluated interactive computer-based weight loss or weight maintenance programs in adults with overweight or obesity. We excluded trials if the duration of the intervention was less than four weeks or the loss to follow-up was greater than 20% overall. Two authors independently extracted study data and assessed risk of bias. Where interventions, control conditions, outcomes and time frames were similar between studies, we combined study data using meta-analysis. We included 14 weight loss studies with a total of 2537 participants, and four weight maintenance studies with a total of 1603 participants. Treatment duration was between four weeks and 30 months. At six months, computer-based interventions led to greater weight loss than minimal interventions (mean difference (MD) -1.5 kg; 95% confidence interval (CI) -2.1 to -0.9; two trials) but less weight loss than in-person treatment (MD 2.1 kg; 95% CI 0.8 to 3.4; one trial). At six months, computer-based interventions were superior to a minimal control intervention in limiting weight regain (MD -0.7 kg; 95% CI -1.2 to -0.2; two trials), but not superior to infrequent in-person treatment (MD 0.5 kg; 95% -0.5 to 1.6; two trials). We did not observe consistent differences in dietary or physical activity behaviors between intervention and control groups in either weight loss or weight maintenance trials. Three weight loss studies estimated the costs of computer-based interventions compared to usual care, however two of the studies were 11 and 28 years old, and recent advances in technology render these estimates unlikely to be applicable to current or future interventions, while the third study was conducted in active duty military personnel, and it is unclear whether the costs are relevant to other settings. One weight loss study reported the cost-effectiveness ratio for a weekly in-person weight loss intervention relative to a computer-based intervention as USD 7177 (EUR 5678) per life year gained (80% CI USD 3055 to USD 60,291 (EUR 2417 to EUR 47,702)). It is unclear whether this could be extrapolated to other studies. No data were identified on adverse events, morbidity, complications or health-related quality of life. Compared to no intervention or minimal interventions (pamphlets, usual care), interactive computer-based interventions are an effective intervention for weight loss and weight maintenance. Compared to in-person interventions, interactive computer-based interventions result in smaller weight losses and lower levels of weight maintenance. The amount of additional weight loss, however, is relatively small and of brief duration, making the clinical significance of these differences unclear.

Impact of Participant and Interventionist Race Concordance on Weight Loss Outcomes

We have previously shown that racial composition of behavioral intervention groups does not affect achieved weight loss. However, it is unclear if the race of the interventionist affects intervention outcomes. The objective of this analysis is to estimate the impact of race concordance between participant and interventionist on weight change in the initial weight loss phase (phase 1) of the Weight Loss Maintenance trial (WLM).A total of 1,685 overweight or obese adults (body mass index [BMI] 25–45 kg/m2) who were taking medication for hypertension and/or dyslipidemia participated in Phase I of the WLM trial. All participants received a 6-month intensive behavioral intervention in groups of 15–20 facilitated by a trained interventionist. The main outcome is change in weight at 6 months.Participants were on average 55 years of age, 67% female and 44% AA. Three of seventeen interventionists were AA, 14 were non-AA. Seventy-three percent of participants shared race concordance with the interventionist. There was a small but statistically significant difference in weight change of participants who were the same race as the interventionist (−5.84 kg, SE 0.17) compared to those who were not race concordant (−5.04 kg, SE 0.33), a difference of 0.8kg, (p= 0.04). The impact of concordance on weight change differed by race (i.e., interaction of race and concordance was significant, p= 0.02).In a post-hoc analysis of a group-based behavioral intervention, race concordance for Non-AA participants was associated with slightly greater weight loss. Race concordance was not associated with weight loss for AA participants.

Dietary Intakes Associated with Successful Weight Loss and Maintenance during the Weight Loss Maintenance Trial

Background Dietary components effective in weight maintenance efforts have not been adequately identified. Objective To determine the effects of changes in dietary consumption on weight loss and maintenance during the Weight Loss Maintenance clinical trial. Design Weight Loss Maintenance was a randomized controlled trial. Successful weight loss participants who completed Phase I of the trial and lost 4 kg were randomized to one of three maintenance intervention arms in Phase II and followed for an additional 30 months. Participants/setting The multicenter trial was conducted from 2003 through 2007. This substudy included 828 successful weight loss participants. Methods The Block Food Frequency Questionnaire (FFQ) was used to assess nutrient intake levels and food group servings. Carbohydrates, proteins, fats, dietary fiber, fruit/vegetable, and dairy servings were utilized as predictor variables. The FFQ was collected on all participants at study entry (beginning of Phase I). Those randomized to Phase II completed the FFQ at three additional time points: randomization (beginning of Phase II), 12 months, and 30 months. Intervention The main intervention focused on long-term maintenance of weight loss using the Dietary Approaches to Hypertension diet. This substudy examined if changes to specific dietary variables were associated with weight loss and maintenance. Statistical analyses performed Linear regression models that adjusted for change in total energy examined the relationship between changes in dietary intake and weight for each time period. Site, age, race, sex, and a race–sex interaction were included as covariates. Results Participants who substituted protein for fat lost, on average, 0.33 kg per 6 months during Phase I ( P<0.0001) and 0.07 kg per 6 months during Phase II ( P<0.0001) per 1% increase in protein. Increased intake of fruits and vegetables was associated with weight loss in Phases I and II: 0.29 kg per 6 months ( P<0.0001) and 0.04 kg per 6 months ( P=0.0062), respectively, per 1-serving increase. Substitution of carbohydrates for fat and protein for carbohydrates were associated with weight loss during both phases. Increasing dairy intake was associated with significant weight loss during Phase II (−0.17 kg per 6 months per 1-serving increase, P=0.0002), but not during Phase I. Dietary fiber revealed no significant findings. Conclusions Increasing fruits, vegetables, and low-fat dairy may help achieve weight loss and maintenance.

Dietary Strategies for Successful Weight Loss and Maintenance: More Evidence Required

Evaluation of the effects of dietary interventions for weight loss on usual food intakes of individuals participating in clinical trials provides an opportunity to identify eating habits that are amenable to change, and to observe how closely these changes align with the intervention’s original dietary prescription. This hinges on a number of assumptions. First, that the study investigators adequately reported the details of the dietary intervention, in terms of the initial key nutrition goals and targets about which the participants were educated. Second, that the changes in dietary intake were measured with sufficient accuracy. Third, that adherence to the prescribed intervention was considered and that the data had appropriate statistical treatment. Inadequate description of dietary intervention components can make it impossible to differentiate between prescribed approaches. For example a systematic review by Avenell and colleagues (1) found that, based on the limited published dietary intervention details within the Methods section of study protocols, it was not possible to discriminate between those that had prescribed a 600 kcal/day deficit vs those that had prescribed a low-fat diet without a stringent energy reduction. Their meta-analysis included 12 randomized controlled trials and indicated that prescribing a low-fat diet to achieve a daily energy deficit or prescribing a 600 kcal/day deficit leads to a similar median weight reduction of 4.5 kg (95% confidence interval 5.7 to 3.4 kg) after 12 months (1). Studies that report dietary intake changes secondary to weight loss interventions tend to focus on total energy and/or macronutrient profiles only, rather than describing changes in intakes of food groups, such as type of or number of daily servings of bread; milk; fruit; vegetables; or energy-dense, nutrient-poor foods. For example, in a systematic review of interventions to treat obesity in children (2), only 11 of 37 randomized controlled trials published any details related to change in dietary intake. Of those, seven reported changes in macronutrient intake profiles, four reported changes at an aggregated food group level (based on a traffic light system where red foods were energy-dense and nutrient-poor and green foods were nutrient-dense and lower in kilojoules), and just one reported food group intake changes at the level of fruit and vegetables and high-fat/high-sugar food intakes (2). Reports of actual consumption by those who are successful in achieving weight loss or subsequent weight loss maintenance are less commonly available. Yet, this information is what dietetics practitioners and their clients want to know and what would assist practitioners in recommending various approaches to treatment. The article by Champagne and colleagues (3) provides a welcome examination of dietary intake changes associated with successful initial weight loss and subsequent weight loss maintenance. Studies such as this address a gap in the evidence base for dietetics practice. Addressing this omission will allow dietetics practitioners to offer evidence-informed, practical dietary advice to individuals seeking weight management advice. As part of the discussion on evidence-based diet and food-based recommendations for weight loss and weight loss maintenance, the concept of what is deemed a successful weight outcome, and the predictors of this success, need to be considered. These factors are discussed by Champagne and colleagues in this issue of the Journal (3). The investigators examined changes in dietary intake across 3 years within a weight loss and weight loss maintenance trial, as well as evidence on changes in diet and food intake during weight loss and weight loss maintenance from other trials, before drawing a conclusion on current evidence on weight loss and weight loss maintenance food-based recommendations.

Branched-chain amino acid levels are associated with improvement in insulin resistance with weight loss.

Insulin resistance (IR) improves with weight loss, but this response is heterogeneous. We hypothesised that metabolomic profiling would identify biomarkers predicting changes in IR with weight loss. Targeted mass spectrometry-based profiling of 60 metabolites, plus biochemical assays of NEFA, β-hydroxybutyrate, ketones, insulin and glucose were performed in baseline and 6 month plasma samples from 500 participants who had lost ≥4 kg during Phase I of the Weight Loss Maintenance (WLM) trial. Homeostatic model assessment of insulin resistance (HOMA-IR) and change in HOMA-IR with weight loss (∆HOMA-IR) were calculated. Principal components analysis (PCA) and mixed models adjusted for race, sex, baseline weight, and amount of weight loss were used; findings were validated in an independent cohort of patients (n = 22). Mean weight loss was 8.67 ± 4.28 kg; mean ∆HOMA-IR was -0.80 ± 1.73, range -28.9 to 4.82). Baseline PCA-derived factor 3 (branched chain amino acids [BCAAs] and associated catabolites) correlated with baseline HOMA-IR (r = 0.50, p < 0.0001) and independently associated with ∆HOMA-IR (p < 0.0001). ∆HOMA-IR increased in a linear fashion with increasing baseline factor 3 quartiles. Amount of weight loss was only modestly correlated with ∆HOMA-IR (r = 0.24). These findings were validated in the independent cohort, with a factor composed of BCAAs and related metabolites predicting ∆HOMA-IR (p = 0.007). A cluster of metabolites comprising BCAAs and related analytes predicts improvement in HOMA-IR independent of the amount of weight lost. These results may help identify individuals most likely to benefit from moderate weight loss and elucidate novel mechanisms of IR in obesity.

Development and Implementation of a Tailored Self-assessment Tool in an Internet-based Weight Loss Maintenance Program

Background: Using the Internet to replicate client/counselor interactions provides a tremendous opportunity to disseminate interventions at relatively low cost per participant. However, there are substantial challenges with this approach. The Weight Loss Maintenance Trial (WLM) compared two long-term weight-maintenance interventions: (1) a personal contact arm and (2) an Internet arm, to a third self-directed control arm. The Internet arm focused on use of an interactive website for support of long-term weight maintenance. This paper describes a highly interactive self-assessment tool developed for use in the WLM trial Internet intervention arm.Methods: The Tailored Self-Assessment (TSA) website tool was an interactive resource for those WLM participants assigned to the Internet arm to review their personal weight-management progress and make choices about future weight-management actions. The TSA was highly tailored and ended with a suggested list of personalized action plans. While the participant could complete the TSA at any time, criteria-based reminder messages prompted participation.Results: The TSA was one of 27 interactive tools on the WLM website. Over the course of the 28 months, the TSA was completed 800 times by the 348 randomized participants. Fifty-three percent of the participants (185/348) used the TSA at least once (range: 0, 110) and 72% of the 185 participants who did complete the TSA at least once, completed it more than once.Conclusion: The Internet has great potential to impact health behavior by attempting to replicate personal counseling. We learned that while development is complex and appears costly, tailored strategies based on client feedback are likely worthwhile and should be formally tested.

Obesity reduction black intervention trial (ORBIT): 18-month results.

Obesity is a chronic condition that is prevalent in black women. The Obesity Reduction Black Intervention Trial (ORBIT) was a randomized controlled weight loss and weight-loss maintenance (WLM) trial. Participants (N = 213) were randomized to the intervention or control groups in August 2005 and September 2006. Follow-up data were collected 6 and 18 months after randomization. The main outcome was change in weight and BMI from baseline to 18 months. The mean weight at baseline was 104.9 kg, and the mean weight loss in the intervention group at 6 months was 3.0 kg and a gain of 0.2 kg in the control group (mean difference between groups in weight change at 6 months, adjusting for baseline weight and cohort, -3.27 kg; 95% confidence interval (CI), -4.50 to -2.05 kg; P < 0.001). Both groups gained weight between 6 and 18 months (mean 1.0 kg in the intervention group and 0.1 kg in the control group). However, intervention participants lost significantly more weight than control participants during the 18-month intervention (adjusted mean difference between groups at 18 months, -2.83 kg; 95% CI, -4.71 to -0.95; P = 0.003). At 18 months, intervention participants were more likely than control participants to have lost at least 5% of baseline weight (24% vs. 12%, P < 0.04). Our results indicate that the ORBIT program did promote weight loss and weight-loss maintenance. However, the results also clearly illustrate there is more to learn about what will contribute to meaningful weight loss and maintenance in this population.

Associations of Internet Website Use With Weight Change in a Long-term Weight Loss Maintenance Program

BackgroundThe Weight Loss Maintenance Trial (WLM) compared two long-term weight-maintenance interventions, a personal contact arm and an Internet arm, with a no-treatment control after an initial six-month Phase I weight loss program. The Internet arm focused on use of an interactive website for support of long-term weight maintenance. There is limited information about patterns of website use and specific components of an interactive website that might help promote maintenance of weight loss.ObjectiveThis paper presents a secondary analysis of the subset of participants in the Internet arm and focuses on website use patterns and features associated with long-term weight maintenance.MethodsAdults at risk for cardiovascular disease (CVD) who lost at least 4 kilograms in an initial 20-week group-based, behavioral weight-loss program were trained to use an interactive website for weight loss maintenance. Of the 348 participants, 37% were male and 38% were African American. Mean weight loss was 8.6 kilograms. Participants were encouraged to log in at least weekly and enter a current weight for the 30-month study period. The website contained features that encouraged setting short-term goals, creating action plans, and reinforcing self-management habits. The website also included motivational modules, daily tips, and tailored messages. Based on log-in and weight-entry frequency, we divided participants into three website use categories: consistent, some, and minimal.ResultsParticipants in the consistent user group (n = 212) were more likely to be older (P = .002), other than African American (P = .02), and more educated (P = .01). While there was no significant difference between website use categories in the amount of Phase I change in body weight (P = .45) or income (P = .78), minimal website users (n = 75) were significantly more likely to have attended fewer Phase I sessions (P = .001) and had a higher initial body mass index (BMI) (P < .001). After adjusting for baseline characteristics including initial BMI, variables most associated with less weight regain included: number of log-ins (P = .001), minutes on the website (P < .001), number of weight entries (P = .002), number of exercise entries (P < .001), and sessions with additional use of website features after weight entry (P = .002).ConclusionParticipants defined as consistent website users of an interactive behavioral website designed to promote maintenance of weight loss were more successful at maintaining long-term weight loss.Trial RegistrationNCT00054925; http://clinicaltrials.gov/ct2/show/NCT00054925 (Archived by WebCite at http://www.webcitation.org/5rC7523ue)

Development and implementation cost analysis of telephone- and Internet-based interventions for the maintenance of weight loss

The Weight Loss Maintenance Trial (WLM) was a multicenter, randomized trial comparing two weight loss maintenance interventions, a personal contact (PC) program with primarily telephone-based monthly contacts, and an Internet-based program (interactive technology, IT), to a self-directed control group, among overweight or obese individuals at high cardiovascular risk. This study describes implementation costs of both interventions as well as IT development costs. Resources were micro-costed in 2006 dollars from the primary perspective of a sponsoring healthcare system considering adopting an extant intervention, rather than developing its own. Costs were discounted at 3 percent annually. Length of trial participation was 30 months (randomization during February-November 2004). IT development costs were assessed over 36 months. Univariate and multivariate, including probabilistic, sensitivity analyses were performed. Total discounted IT development costs over 36 months were $839,949 ($2,414 per IT participant). Discounted 30-month implementation costs for 342 PC participants were $537,242 ($1,571 per participant), and for 348 IT participants, were $214,879 ($617 per participant). Under all plausible scenarios, PC implementation costs exceeded IT implementation costs. Costs of implementing and operating an Internet-based intervention for weight loss maintenance were substantially less than analogous costs of an intervention using standard phone and in-person contacts and are of a magnitude that would be attractive to many health systems, subject to demonstration of cost-effectiveness.

Reliability of RT3 Accelerometers among Overweight and Obese Adults

Accurate and reliable measurement of physical activity plays an important role in assessing effective lifestyle interventions for obesity. This study examined reliability of accelerometer-based estimates of physical activity levels of overweight and obese adults before and after a lifestyle weight loss program. Participants were overweight and obese (body mass index = 25-45 kg x m) members (n = 1592; 67% female, 42% African American) of the multicenter weight loss maintenance trial. They wore RT3 accelerometers during waking hours for 7 d at baseline and after a 6-month weight loss intervention that included diet and physical activity recommendations. Moderate-to-vigorous physical activity (MVPA) and MVPA occurring in bouts >or=10 min (bout MVPA) were assessed. At baseline, wear time minimums of 10 and 6 h.d resulted in similar average minutes per day of MVPA (18.3 and 18.0 min) and MVPA bout minutes per day (6.9 and 6.7 min). Similar wear times occurred after the weight loss intervention for MVPA (27.0 and 26.8 min) and bout MVPA (15.1 and 15.0 min). Reliability measurements by intraclass correlation (ICC) were larger for 4 versus 2 d x wk minimum wear time for both MVPA and bout MVPA (4-d ICC = 0.27-0.44 and 2-d ICC = 0.19-0.38), but there was little increase in ICC comparing 4 (ICC = 0.27-0.44) and 7 d x wk (ICC = 0.30-0.46). Longer wear time requirements did not result in significant increases in reliability. Using 4 d of data with >or=6 h x d of wear time optimized the balance between ICC and participant burden in overweight and obese adults before and after a weight loss intervention. Future investigations using accelerometers to estimate MVPA in overweight and obese samples can consider requiring less monitor wear time.

Successful Weight‐loss Maintenance in Relation to Method of Weight Loss

This study examined the relation between method of weight loss and long-term maintenance among successful weight losers enrolled in a weight-loss maintenance trial. Participants were 186 adults (mean age = 51.6 +/- 10.7 years, mean BMI = 28.6 +/- 4.7 kg/m(2)) enrolled in the STOP Regain trial who had lost at least 10% of their body weight in the past 2 years using a very low-calorie diet (VLCD; n = 24), commercial program (n = 95), or self-guided approach (n = 67). Participants were randomized to a weight-maintenance intervention delivered face to face or over the internet or to a newsletter control condition, and followed for 18 months. At study entry, individuals who had used a VLCD had achieved a weight loss of 24% of their maximum weight within the past 2 years compared to 17% achieved by those who had used a commercial program or self-guided approach (P < 0.001). However, individuals who had used a VLCD regained significantly more weight than the other two groups and by 6 months, there were no significant differences in overall percent weight loss (i.e., initial weight loss and maintenance) between VLCD, commercial, and self-guided methods. In contrast, individuals who had used a self-guided approach maintained their weight losses from baseline through 18 months. The large initial weight losses achieved by individuals who had used a VLCD were not maintained over time, whereas individuals who had used a self-guided approach maintained their initial weight losses with the greatest success. The generalizability of these findings is limited by the sizeable weight losses achieved by study participants.

Design considerations and rationale of a multi-center trial to sustain weight loss: the Weight Loss Maintenance Trial.

The Weight Loss Maintenance Trial (WLM) is a multi-center, randomized, controlled trial that compares the effects of two 30-month maintenance interventions, i.e., Personal Contact (PC) and Interactive Technology (IT) to a self-directed usual care control group (SD), in overweight or obese individuals who are at high risk for cardiovascular disease. This paper provides an overview of the design and methods, and design considerations and lessons learned from this trial. All participants received a 6-month behavioral weight loss program consisting of weekly group sessions. Participants who lost 4 kg were randomized to one of three conditions (PC, IT, or SD). The PC condition provided monthly contacts with an interventionist primarily via telephone and quarterly face-to-face visits. The IT condition provided frequent, individualized contact through a tailored, website system. Both the PC and IT maintenance programs encouraged the DASH dietary pattern and employed theory-based behavioral techniques to promote maintenance. Design considerations included choice of study population, frequency and type of intervention visits, and choice of primary outcome. Overweight or obese persons with CVD risk factors were studied. The pros and cons of studying this population while excluding others are presented. We studied intervention contact strategies that made fewer demands on participant time and travel, while providing frequent opportunities for interaction. The primary outcome variable for the trial was change in weight from randomization to end of follow-up (30 months). Limits to generalizability are discussed. Individuals in need of weight loss strategies may have been excluded due to barriers associated with internet use. Other participants may have been excluded secondary to a comorbid condition. This paper highlights the design and methods of WLM and informs readers of discussions of critical issues and lessons learned from the trial.

Weight Loss During the Intensive Intervention Phase of the Weight-Loss Maintenance Trial

To improve methods for long-term weight management, the Weight Loss Maintenance (WLM) trial, a four-center randomized trial, was conducted to compare alternative strategies for maintaining weight loss over a 30-month period. This paper describes methods and results for the initial 6-month weight-loss program (Phase I). Eligible adults were aged > or =25, overweight or obese (BMI=25-45 kg/m2), and on medications for hypertension and/or dyslipidemia. Anthropomorphic, demographic, and psychosocial measures were collected at baseline and 6 months. Participants (n=1685) attended 20 weekly group sessions to encourage calorie restriction, moderate-intensity physical activity, and the DASH (dietary approaches to stop hypertension) dietary pattern. Weight-loss predictors with missing data were replaced by multiple imputation. Participants were 44% African American and 67% women; 79% were obese (BMI> or =30), 87% were taking anti-hypertensive medications, and 38% were taking antidyslipidemia medications. Participants attended an average of 72% of 20 group sessions. They self-reported 117 minutes of moderate-intensity physical activity per week, kept 3.7 daily food records per week, and consumed 2.9 servings of fruits and vegetables per day. The Phase-I follow-up rate was 92%. Mean (SD) weight change was -5.8 kg (4.4), and 69% lost at least 4 kg. All race-gender subgroups lost substantial weight: African-American men (-5.4 kg +/- 7.7); African-American women (-4.1 kg +/- 2.9); non-African-American men (-8.5 kg +/- 12.9); and non-African-American women (-5.8 kg +/- 6.1). Behavioral measures (e.g., diet records and physical activity) accounted for most of the weight-loss variation, although the association between behavioral measures and weight loss differed by race and gender groups. The WLM behavioral intervention successfully achieved clinically significant short-term weight loss in a diverse population of high-risk patients.

Weight Loss During the Intensive Intervention Phase of the Weight-Loss Maintenance Trial

Weight Loss During the Intensive Intervention Phase of the Weight-Loss Maintenance Trial

Long-term pharmacotherapy for obesity and overweight.

Worldwide prevalence rates of obesity and overweight are rising and safe and effective treatment strategies are urgently needed. A number of anti-obesity agents have been studied in short-term clinical trials, but long-term efficacy and safety need to be established. To assess/compare the effects and safety of approved anti-obesity medications in clinical trials of at least one-year duration. MEDLINE, EMBASE, the Cochrane Controlled Trials Register, the Current Science Meta-register of Controlled Trials, and reference lists of original studies and reviews were searched. Date of last search was December 2002. Drug manufacturers and two obesity experts were contacted in to detect unpublished trials. No language restrictions were imposed. Double-blind, randomised controlled weight loss and weight maintenance trials of approved anti-obesity agents that 1) enrolled adult overweight or obese patients, 2) included a placebo control group or compared two or more anti-obesity drugs 3) used an intention-to-treat analysis, and 4) had a minimum follow-up period of one year. Abstracts and pseudo-randomised trials were not included. Two reviewers independently assessed all potentially relevant citations for inclusion and methodological quality. The primary outcome measure was weight loss. Of the eight anti-obesity agents investigated, only orlistat and sibutramine trials met inclusion criteria. Eleven orlistat weight loss studies (four of which reported a second year weight maintenance phase) and five sibutramine studies (three weight loss and two weight maintenance trials) were included. Attrition rates averaged 33% during the weight loss phase of orlistat trials and 43% in sibutramine studies. All patients received lifestyle modification as a co-intervention. Compared to placebo, orlistat-treated patients lost 2.7 kg (95% CI: 2.3 kg to 3.1 kg) or 2.9% (95% CI: 2.3 % to 3.4%) more weight and patients on sibutramine experienced 4.3 kg (95% CI: 3.6 kg to 4.9 kg) or 4.6% (95% CI: 3.8% to 5.4%) greater weight loss. The number of patients achieving ten percent or greater weight loss was 12% (95% CI: 8% to 16%) higher with orlistat and 15% (95% CI: 4% to 27%) higher with sibutramine therapy. Weight loss maintenance results were similar. Orlistat caused gastrointestinal side effects and sibutramine was associated with small increases in blood pressure and pulse rate. Studies evaluating the long-term efficacy of anti-obesity agents are limited to orlistat and sibutramine. Both drugs appear modestly effective in promoting weight loss; however, interpretation is limited by high attrition rates. Longer and more methodologically rigorous studies of anti-obesity drugs that are powered to examine endpoints such as mortality and cardiovascular morbidity are required to fully evaluate any potential benefit of such agents.

Long-term pharmacotherapy for obesity and overweight.

Worldwide prevalence rates of obesity and overweight are rising and safe and effective treatment strategies are urgently needed. A number of anti-obesity agents have been studied in short-term clinical trials, but long-term efficacy and safety need to be established. To assess/compare the effects and safety of approved anti-obesity medications in clinical trials of at least one-year duration. MEDLINE, EMBASE, the Cochrane Controlled Trials Register, the Current Science Meta-register of Controlled Trials, and reference lists of original studies and reviews were searched. Date of last search was December 2002. Drug manufacturers and two obesity experts were contacted in to detect unpublished trials. No language restrictions were imposed. Double-blind, randomised controlled weight loss and weight maintenance trials of approved anti-obesity agents that 1) enrolled adult overweight or obese patients, 2) included a placebo control group or compared two or more anti-obesity drugs 3) used an intention-to-treat analysis, and 4) had a minimum follow-up period of one year. Abstracts and pseudo-randomised trials were not included. Two reviewers independently assessed all potentially relevant citations for inclusion and methodological quality. The primary outcome measure was weight loss. Of the eight anti-obesity agents investigated, only orlistat and sibutramine trials met inclusion criteria. Eleven orlistat weight loss studies (four of which reported a second year weight maintenance phase) and five sibutramine studies (three weight loss and two weight maintenance trials) were included. Attrition rates averaged 33% during the weight loss phase of orlistat trials and 43% in sibutramine studies. All patients received lifestyle modification as a co-intervention. Compared to placebo, orlistat-treated patients lost 2.7 kg (95% CI: 2.3 kg to 3.1 kg) or 2.9% (95% CI: 2.3 % to 3.4%) more weight and patients on sibutramine experienced 4.3 kg (95% CI: 3.6 kg to 4.9 kg) or 4.6% (95% CI: 3.8% to 5.4%) greater weight loss. The number of patients achieving ten percent or greater weight loss was 12% (95% CI: 8% to 16%) higher with orlistat and 15% (95% CI: 4% to 27%) higher with sibutramine therapy. Weight loss maintenance results were similar. Orlistat caused gastrointestinal side effects and sibutramine was associated with small increases in blood pressure and pulse rate. Studies evaluating the long-term efficacy of anti-obesity agents are limited to orlistat and sibutramine. Both drugs appear modestly effective in promoting weight loss; however, interpretation is limited by high attrition rates. Longer and more methodologically rigorous studies of anti-obesity drugs that are powered to examine endpoints such as mortality and cardiovascular morbidity are required to fully evaluate any potential benefit of such agents.