Effect of meal replacement on metabolic risk factors in overweight and obese subjects.

AIM

Our objective was to assess alterations in metabolic risk factors, body weight, fat mass and hormonal parameters following 6 weeks of lifestyle intervention with increased physical activity and either a meal-replacement regimen or a low calorie diet.

RESEARCH METHODS AND PROCEDURES

90 overweight or obese subjects (age 47 +/- 7.5 years, weight 90.6 +/- 11.3 kg, BMI 31.5 +/- 2.3) were included in this randomized controlled clinical trial. Subjects in the fat-restricted low-calorie-diet group (LCD-G; n = 30) received 2 dietary counseling sessions and instructions on how to increase physical activity. Subjects in the meal-replacement-diet group (MRD-G; n = 60) received the same lifestyle education and were instructed to replace 2 daily meals by a low-calorie high soy-protein drink.

RESULTS

Subjects in the MRD-G lost significantly more weight (6.4 vs. 3.1 kg, p < 0.01) and fat mass (5.1 vs. 2.8 kg, p < 0.01) than the LCD-G. Most metabolic risk parameters were reduced in both the MRD-G and the LCD-G; however, subjects in the MRD-G showed a higher reduction in waist circumference (6.1 vs. 1.8 cm, p < 0.01) and a larger decrease in triglycerides (-19.6 vs. +12.5 mg/dl, p < 0.01). The prevalence of the metabolic syndrome was reduced in subjects in the MRD-G only (-12%, p < 0.05) compared to an unchanged risk score in the LCD-G. The reductions in leptin (18.2 vs. 6.97 ng/ml) and insulin (4.92 vs. 0.58 microU/ml) were only significant in the MRD-G (p < 0.01).

DISCUSSION

Our data suggest that even over a short period of time, a meal-replacement diet is more effective in reducing metabolic risk factors, insulin, and leptin, and in improving anthropometric measures than a fat-restricted low-calorie diet.