Weight loss with meal replacement and meal replacement plus snacks: a randomized trial

OBJECTIVE: To evaluate whether snacking would improve weight loss and weight maintenance in overweight individuals within the context of a structured meal replacement (MR) weight loss program. DESIGN: A prospective 24 week, 2 (snacking vs nonsnacking) x 2 (MR vs meal replacement augmented with snacks (MRPS)) randomized trial. Participants were instructed to limit their total daily intake to 1200 (women) or 1500 (men) kcals. Those receiving the MR program were instructed not to snack while those in the MRPS program were told to snack three times per day. SUBJECTS: A total of 100 participants were block-randomized, based on prestudy snacking status ( high vs low), to receive a standard meal replacement program ( MR) or MRPS. MEASUREMENTS: Weight, height, blood pressure, lipid fractions, glucose, and insulin were assessed at the baseline, 12-, and 24 weeks. RESULTS: Completers analysis at 24 weeks demonstrated a significant time effect ( F( 1,46) 44.6, P < 0.001), indicating that all participants lost significant amounts of weight regardless of group assignment. An intention-to-treat model resulted in similar results. By week 24, the average weight loss across groups was 4.6 kg. There also were significant improvements across all groups among completers for systolic blood pressure (P = 0.047), cholesterol (P = 0.001), LDL (P = 0.001), glucose ( P = 0.004), and insulin (P = 0.001) at week 12, and glucose (P = 0.001) and insulin at week 24 (P = 0.003). CONCLUSIONS: Our results suggest that a participant's preferences for snacking did not affect their response to treatment. Snackers and nonsnackers responded equally well whether they received a standard meal replacement program or one augmented with snacks.