Intentional weight loss and changes in symptoms of depression: a systematic review and meta-analysis.

OBJECTIVE: Obesity is related to increased risk of several health complications, including depression. Many studies have reported improvements in mood with weight loss, but results have been equivocal. The present meta-analysis examined changes in symptoms of depression that were reported in trials of weight loss interventions. Between-groups comparisons of different weight loss methods (for example, lifestyle modification, diet-alone and pharmacotherapy) were examined, as were within-group changes for each treatment type. METHOD: MEDLINE was searched for articles published between 1950 and January 2009. Several obesity-related terms were intersected with terms related to depression. Results were filtered to return only studies of human subjects, published in English. Of 5971 articles, 394 were randomized controlled trials. Articles were excluded if they did not report mean changes in weight or symptoms of depression, included children or persons with psychiatric disorders (other than depression), or provided insufficient data for analysis. Thirty-one studies (n=7937) were included. Two authors independently extracted a description of each study treatment, sample characteristics, assessment methods and changes in weight and symptoms of depression. Treatments were categorized as lifestyle modification, non-dieting, dietary counseling, diet-alone, exercise-alone, pharmacotherapy, placebo or control interventions. RESULTS: Random effects models found that lifestyle modification was superior to control and non-dieting interventions for reducing symptoms of depression, and marginally better than dietary counseling and exercise-alone programs. Exercise-alone programs were superior to controls. No differences were found for comparisons of pharmacologic agents and placebos. Within-group analyses found significant reductions in symptoms of depression for nearly all active interventions. A meta-regression found no relationship between changes in weight and changes in symptoms of depression in lifestyle modification interventions. CONCLUSIONS: On average, obese individuals in weight loss trials experienced reductions in symptoms of depression. Future studies should examine incidence and resolution of clinically significant depressive disorders with weight loss interventions.

Targeting dietary fat or glycemic load in the treatment of obesity and type 2 diabetes: a randomized controlled trial.

AIMS: To compare the effects of lifestyle modification programs that prescribe low-glycemic load (GL) vs. low-fat diets in a randomized trial. METHODS: Seventy-nine obese adults with type 2 diabetes received low-fat or low-GL dietary instruction, delivered in 40-week lifestyle modification programs with identical goals for calorie intake and physical activity. Changes in weight, HbA(1c), and other metabolic parameters were compared at weeks 20 and 40. RESULTS: Weight loss did not differ between groups at week 20 (low-fat: -5.7±3.7%; low-GL: -6.7±4.4%, p=.26) or week 40 (low-fat: -4.5±7.5%; low-GL: -6.4±8.2%, p=.28). Adjusting for changes in antidiabetic medications, subjects on the low-GL diet had larger reductions in HbA(1c) than those on the low-fat diet at week 20 (low-fat: -0.3±0.6%; low-GL: -0.7±0.6%, p=.01), and week 40 (low-fat: -0.1±1.2%; low-GL: -0.8±1.3%; p=.01). Groups did not differ significantly on any other metabolic outcomes (p≥.06). CONCLUSIONS: Results suggest that targeting GL, rather than dietary fat, in a low-calorie diet can significantly enhance the effect of weight loss on HbA(1c) in patients with type 2 diabetes.

Attrition from randomized controlled trials of pharmacological weight loss agents: a systematic review and analysis.

Clinical trials of obesity treatments have been limited by substantial dropout. Participant-level variables do not reliably predict attrition, and study-level variables have not yet been examined. We searched MEDLINE and identified 24 large randomized controlled trials of weight loss medications. These trials were comprised of 23 placebo and 32 drug groups. Two authors independently extracted the following for each treatment group: (i) treatment received; (ii) design characteristics (inclusion of a lead-in period, selection of participants with weight-related comorbidities, study location and number of study visits); (iii) sample characteristics (sample size, % female, and mean baseline age and body mass index); and (iv) attrition (total, adverse event [AE]-related and non-AE-related) at 1 year. The primary outcome was total attrition, which was significantly related to treatment (i.e. 34.9%, 28.6%, 28.3% and 35.1% in placebo, orlistat, sibutramine and rimonabant groups, respectively, P < 0.0001). In adjusted multivariable models, total attrition was significantly lower in groups that completed a pre-randomization lead-in period than in those that did not (29.1% vs. 39.9%, P < 0.01). Gender also was significantly related to total attrition; groups with more women had higher dropout (P < 0.01). The pattern was similar for predicting non-AE-related attrition. Findings suggest ways to design studies that maximize retention.

The role of patients' expectations and goals in the behavioral and pharmacological treatment of obesity.

OBJECTIVE: To investigate weight loss expectations and goals among obese treatment seekers and to examine the relationships of these expectations and goals to treatment outcomes. METHOD: Participants were 180 obese men and women (age 43.8+/-10.1 years; body mass index 37.6+/-4.2 kg/m(2)) who received one of four-year-long treatments that combined behavioral and pharmacological methods. Before treatment, they reported the amount of weight they realistically expected to lose after 4, 12, 26 and 52 weeks of treatment, as well as their ultimate weight loss goals. Expectations and goals were compared across treatment groups and examined in relation to previous weight loss efforts, weight loss and regain in treatment, attrition, satisfaction with treatment and mood. RESULTS: Participants in all treatment groups expected reductions at week 52 that were significantly greater than the 5-15% of initial weight they were told was realistic and significantly more than they had ever lost before. Weight loss expectations were unrelated to achieved weight loss in all groups but one, in which greater expectations were associated with greater losses. Failure to meet weight loss expectations for the first 26 weeks of treatment was related to lower satisfaction ratings, but was not related to weight regain or attrition over the next 26 weeks. Symptoms of depression were reduced from baseline, regardless of whether participants achieved or failed to achieve their expected weight losses. CONCLUSION: Across groups, we observed no negative consequences of having (and failing to meet) unrealistic expectations for weight loss.