Ard JR, Lewis KH, Rothberg A, Auriemma A, Coburn Sl, Cohen SS, Loper J, Matarese L, Pories WJ, Periman S. 2019. Effectiveness of a total meal replacement program (OPTIFAST® program) on weight loss: Results from the OPTIWIN study. Obesity (Silver Spring) 27(1):22-29.
Objective: The aim of this study was to test the effectiveness of the OPTIFAST program (OP), a total meal
replacement dietary intervention, compared with a food-based (FB) dietary plan for weight loss.
Methods: Participants with BMI 30 to 55 kg/m2, age 18 to 70 years old, were randomized to OP or FB die-
tary and lifestyle interventions for 26 weeks, followed by a weight-maintenance phase. Outcomes were
percent change in body weight (%WL) from baseline to weeks 26 and 52, associated changes in body com-
position (using dual energy x-ray absorptiometry), and adverse events. Primary analysis used repeated-
measures multivariable linear mixed models to compare outcomes between groups in a modified
intention-to-treat fashion (mITT).
Results: A total of 273 participants (83% of randomized; 135 OP, 138 FB) made up the mITT population.
Mean age was 47.1 ± 11.2 years; 82% were female and 71% non-Hispanic white. Baseline BMI was 38.8 ± 5.9
kg/m2. At 26 weeks, OP %WL was 12.4% ± 0.6% versus 6.0% ± 0.6% in FB (P < 0.001). At 52 weeks, OP
%WL was 10.5% ± 0.6% versus 5.5% ± 0.6% in FB (P < 0.001). Fat mass loss was greater for OP; lean mass
loss was proportional to total weight loss. There was no difference in serious adverse event rates between
Conclusions: Compared with an FB approach, OP was more effective with greater sustained weight loss.