Weight-Loss Outcomes: A Systematic Review and Meta-Analysis of Weight-Loss Clinical Trials with a Minimum 1-Year Follow-Up

Minneapolis Heart Institute, Minneapolis, Minnesota, United States
Journal of the American Dietetic Association (Impact Factor: 3.92). 11/2007; 107(10):1755-67. DOI: 10.1016/j.jada.2007.07.017
Source: PubMed


To assist health professionals who counsel patients with overweight and obesity, a systematic review was undertaken to determine types of weight-loss interventions that contribute to successful outcomes and to define expected weight-loss outcomes from such interventions.
A search was conducted for weight-loss-focused randomized clinical trials with >or=1-year follow-up. Eighty studies were identified and are included in the evidence table.
The primary outcomes were a measure of weight loss at 6, 12, 24, 36, and 48 months. Eight types of weight-loss interventions-diet alone, diet and exercise, exercise alone, meal replacements, very-low-energy diets, weight-loss medications (orlistat and sibutramine), and advice alone-were identified. By using simple pooling across studies, subjects mean amount of weight loss at each time point for each intervention was determined.
Efficacy outcomes were calculated by meta-analysis and provide support for the pooled data. Hedges' gu was combined across studies to obtain an average effect size (and confidence level).
A mean weight loss of 5 to 8.5 kg (5% to 9%) was observed during the first 6 months from interventions involving a reduced-energy diet and/or weight-loss medications with weight plateaus at approximately 6 months. In studies extending to 48 months, a mean 3 to 6 kg (3% to 6%) of weight loss was maintained with none of the groups experiencing weight regain to baseline. In contrast, advice-only and exercise-alone groups experienced minimal weight loss at any time point.
Weight-loss interventions utilizing a reduced-energy diet and exercise are associated with moderate weight loss at 6 months. Although there is some regain of weight, weight loss can be maintained. The addition of weight-loss medications somewhat enhances weight-loss maintenance.

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Available from: Nicolaas P Pronk, Oct 06, 2015
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    • "African-American women have the highest prevalence of obesity compared with any other subgroup, with 56.6% classified as obese, defined as a body mass index (BMI) ≥ 30 kg/m 2 , compared with 32.8% of their white counterparts [1]. In general, behavioral weight loss interventions have been successful in reducing weight among obese adults (e.g., [2] [3] [4]). According to the National Institute of Health clinical guidelines, behavioral weight loss interventions featuring diet (decreased energy intake), physical activity (increased energy expenditure ), and behavioral therapy (behavior modification) components typically result in approximately 5–10% weight loss after 6 months of intervention [2] [5] [6]. "
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