Meal replacements, reduced energy density eating, and weight loss maintenance in primary care patients: a randomized...

To compare the presence or absence of meal replacements (MRs) and an energy density (ED) intervention to facilitate weight loss maintenance.

A total of 238 overweight primary care patients (mean body mass index = 39.5 kg/m(2) ) began the study; 132 completed the 12-week weight loss phase. Participants were randomly assigned to one of four maintenance conditions formed by crossing the presence or absence of MRs (MR+/MR-) and of the ED program (ED+/ED-) during a subsequent 9-month maintenance phase. Follow-up assessments occurred 1 and 2 years after treatment termination.

Participants initially lost 6.1 kg. Analyses of variance based on weight change from the beginning of the maintenance phase to the 2-year follow-up produced a significant interaction. All groups except ED+/MR- regained substantial weight during follow-up; the ED+/MR- group regained significantly less weight than the control group at both follow-up assessments. No significant effects of treatment were found for several variables that were expected to mediate these outcomes.

Because weight losses achieved in lifestyle change programs for obesity are rarely maintained, the superior outcome achieved by the ED+/MR- condition is notable. Nonetheless, methodological issues and inability to identify a potential mediator of this outcome make replication of this finding essential.