Objective:
To evaluate the effects of snacking on weight loss and weight maintenance in overweight individuals who followed a meal replacement weight loss plan (Slim·Fast). Secondarily, to determine whether snacking improves other markers of cardiovascular disease risk, including blood pressure, plasma lipoproteins, fasting blood glucose, and insulin.

Method
Researchers followed 100 men and women between the ages of 35 and 55, with a BMI between 25 and 30. Participants were randomly assigned to one of two groups for a 24-week program. The two groups were “meal replacements alone (Slim·Fast)” (MRP), and “meal replacement plus snacks (Slim·Fast plus snacks)” (MRPS). Within these two groups, participants were divided into “Snackers” (S) and “Nonsnackers” (NS). All participants were asked to use a minimum of two Slim·Fast products a day. Those in the MRPS group were told to use Slim·Fast products for both meals and snacks. Those in the non-snacking group were told to use only the Slim·Fast products for meals and Slim·Fast snack bars or other foods (such as fruit or low-calorie yogurt) for their three snacks a day. Those in the MRP group were explicitly told not to consume snacks. Women were instructed to follow a regimen of approximately 1200 calories/day; men, 1500 calories/day. All participants visited the center once a week where they received brief counseling (20 minutes) by a registered dietitian.

Results
There were no significant differences at baseline between patients randomized to the four groups. The only exception was differences in total cholesterol levels (P=0.050) between the snackers (S) receiving MRPS (219.08+-30.60) and the nonsnackers (NS) receiving MRPS (193.60 +-30.83).

All of the groups experienced significant weight loss at 12 and 24 weeks, with no significant differences between the groups. The table below presents weight changes (kg) for the four treatment groups based on completers at each end point.

CONCLUSION:
Findings suggest that an individual’s preference for snacking does not adversely affect their weight loss results. Snackers and nonsnackers alike responded equally well to a meal replacement weight loss regimen whether they received a standard program or one augmented with snacks.

Source:
Weight loss with meal replacement and meal replacement plus snacks: a randomized trial. Poston, WSC et al. Int J Obes. 2005; 29: 1107-1114.