Meal replacements in the treatment of adolescent obesity: a randomized controlled trial

Abstract

Use of meal replacements (MRs) in lifestyle modification programs (LMPs) for obese adults significantly increases weight loss, compared with prescription of an isocaloric conventional diet (CD). This 12-month randomized trial examined 113 obese adolescents (mean ± s.d. age of 15.0 ± 1.3 years and BMI of 37.1 ± 5.1 kg/m2) who were assigned to a LMP, combined with meal plans of 1300-1500 kcal/day of CD (self-selected foods) or MR (three SlimFast shakes, one prepackaged meal, five vegetable/fruit servings). After month 4 (phase 1), participants originally treated with MR were unmasked to their phase 2 (months 5-12) random assignment: continued use of MR (i.e., MR+MR) or transitioned to CD (i.e., MR+CD). Participants initially treated with CD in phase 1, continued with CD (i.e., CD). All three groups were treated for an additional 8 months (phase 2). Regression models were used to evaluate percentage change in BMI from baseline to month 4 (phase 1), months 5-12 (phase 2), and baseline to month 12. At month 4, participants assigned to MR (N = 65) achieved a mean (±s.e.) 6.3 ± 0.6% reduction in BMI, compared to a significantly (P = 0.01) smaller 3.8 ± 0.8% for CD participants (N = 37). In phase 2, BMI increased significantly (P < 0.001) in all three conditions, resulting in no significant (P = 0.39) differences between groups in percentage change in BMI at month 12. Across groups, mean reduction in BMI from baseline to month 12 was 3.4 ± 0.7% (P < 0.01). Use of MR significantly improved short-term weight loss, compared with CD, but its continued use did not improve maintenance of lost weight.

Conflict of interest statement

None of the authors has any conflicts of interest to declare.

Figures

Figure 1. Consort diagram

Consort diagram showing the flow of participants through each stage of the randomized trial. During Phase 1, participants were randomized to either conventional diet or meal replacement with maintenance condition masked. During Phase 2, the maintenance conditions were unmasked for participants originally assigned to meal replacement and participants either returned to conventional foods or continued use of meal replacements for months 5–12. The three groups at Month 12 were CD, MR/CD, and MR/MR.

Figure 2. Percentage Reduction in Initial BMI at Month 4 and Month 12

Percentage reduction in initial BMI at month 4 included participants treated by CD or MR. Percentage reduction in initial BMI at month 12 included participants treated by CD (circle), MR/CD (triangle), or MR/MR (square). The three treatment groups were CD (conventional diet); MR/CD (meal replacement in months 1–4 followed by conventional diet in months 5–12); and MR/MR (meal replacement in months 1–4 followed by meal replacement in months 5–12). Participants in MR had significantly greater weight losses at month 4 compared to CD. However, participants who were in the two MR conditions did not achieve significantly greater weight losses than those in the CD condition at month 12.