Effectiveness of a Medifast meal replacement program on weight, body composition and cardiometabolic risk factors in overweight and obese adults: a multicenter systematic retrospective chart review study

BACKGROUND: Recent medical guidelines emphasize the importance of actively treating overweight and obesity with diet and lifestyle intervention to achieve ≥5 % weight loss in a 6-month period. Commercial programs offer one approach provided there is evidence of their efficacy and safety. This study was conducted to evaluate the effectiveness of the Medifast® 4 & 2 & 1 Plan™ on weight loss, body composition and cardiometabolic risk factors in overweight and obese adults. METHODS: A systematic retrospective chart review of 310 overweight and obese clients following the Medifast 4 & 2 & 1 Plan at one of 21 Medifast Weight Control Centers® was conducted. Data were recorded electronically and key data points were independently verified. The primary endpoint was change from baseline body weight at 12 weeks. Within group paired t-tests were used to examine changes from baseline in a completers population. Differences between gender and age subgroups were examined using bivariate t-tests and mixed model regression analyses. RESULTS: For the primary endpoint at 12 weeks, body weight among completers (n = 185) was reduced by a mean of 10.9 ± 5.6 kg (-10.1 %, p < 0.0001), and at 24 weeks (n = 81) mean weight was reduced by 16.0 ± 7.9 kg (-14.3 %). At 12 and 24 weeks, 85 % and 96 % of those remaining on the plan, respectively, had lost ≥5 % of their baseline body weight. Lean mass was preserved to within 5 % of baseline throughout the 24 weeks, and fat mass represented ≥80 % of the body weight lost from 12 weeks onward. Men, women, seniors (≥65 years), and non-seniors (<65 years) all had significant weight reductions with preservation of lean mass. Significant improvements in blood pressure, pulse and waist-to-hip ratio were observed. Mean weight regain among the subset who entered a formal maintenance phase was <2 % during an average follow-up of 34 weeks. The meal plan was well tolerated, and program adherence was >85 %. CONCLUSIONS: The 4 & 2 & 1 Plan used at Medifast Weight Control Centers was effective for weight loss, preservation of lean mass and improvement in cardiometabolic risk factors. The plan was generally well tolerated in a broad population of overweight and obese adults. #NCT02150837. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12937-015-0062-8) contains supplementary material, which is available to authorized users.