Objective: To examine changes in biomarkers of disease risk after 51 months of reduced energy intake and sustained weight loss.
Research methods and procedures: This study was conducted as a prospective, randomized, two-arm, parallel intervention for 12 weeks followed by a prospective, single-arm, 4-year trial in a university-based hospital clinic. One hundred patients were randomly assigned to one of two dietary interventions for 3 months. Group A was prescribed an energy-restricted diet of 1200 to 1500 kcal/d, and group B was prescribed an isocaloric diet, whereby two of three meals were replaced with nutrient-fortified liquid meal replacements. After 3 months, the patients were prescribed the same caloric reduction and used once-daily replacements for the succeeding 4 years. Body weight and blood pressure were checked monthly. Biomarkers of disease risk were measured after 3, 9, 15, 27, and 51 months.
Results: During the 3-month weight-loss period, body weight was reduced by 1.5 +/- 0.4% and 7.8 +/- 0.5% (mean +/- SEM) for groups A and B, respectively. After 4 years, 75% of the patients were evaluated. Total mean weight loss was 3.3 +/- 0.8% and 8.4 +/- 0.8% for groups A and B, respectively. Both groups of patients showed significant improvement in glucose, insulin, triacylglycerol, and systolic blood pressure. Cholesterol concentrations were reduced in patients with high initial cholesterol levels and maintenance of a 7% weight loss.
Discussion: Providing a structured meal plan with liquid meal replacements is an effective treatment for obese subjects. Long-term maintenance of weight loss with meal replacements improves biomarkers of disease risk.