Comparison of Commercially‐Available Portion Controlled Weight Loss Programs with a Self‐Directed Diet: A Randomized Clinical Trial

Abstract

The aim of this randomized, four‐arm parallel study was to examine changes in body weight and related outcomes over a 16‐week period in response to three different commercially‐available structured weight loss programs, each compared to a self‐directed diet. Subjects included predominantly white (77.0%) overweight/obese men (n = 38) and women (n = 123), with a mean age of 50.2 y, body weight of 93.4 kg, and body mass index (BMI) of 33.5 kg/m2. The 161 subjects were randomly assigned (stratified by BMI and age) to a self‐directed Dietary Approaches to Stop Hypertension (DASH) diet, or one of three different Nutrisystem programs providing pre‐packaged portion controlled foods and shakes: 1) My Way; 2) Turbo 10; or 3) a Nutrisystem program modeled after the DASH diet (NS‐DASH). Daily energy intake targets were 1200 kcal/d for women and 1500 kcal/d for men, except for the first week of Turbo 10, during which subjects targeted 1000 kcal/d. Key outcomes included changes in body weight, body composition via dual‐energy x‐ray absorptiometry (DXA), and total body circumference (waist, hip, chest, arm, and thigh) at 4 and 16 weeks. Data from the 158 subjects that completed at least one post‐randomization visit were included in an intent‐to‐treat analysis. Each group had a significant decrease in body weight from baseline at 4 weeks [mean difference from baseline (95% confidence interval, CI) in kg]: self‐directed = −1.3 (−2.0, −0.6); My Way = −3.1 (−3.8, −2.4); Turbo 10 = −3.8 (−4.5, −3.1); NS‐DASH −3.4 (−4.0, −2.7); p < 0.05 for all] and at 16 weeks [self‐directed = −1.8 (−2.9, −0.8); My Way = −6.0 (−7.4, −4.5); Turbo 10 = −5.9 (−7.5, −4.3); NS‐DASH − 6.0 (−7.6, −4.5); p < 0.05 for all]. Significant reductions in total fat mass were also observed in each group at 4 weeks [mean difference from baseline (95% CI) in kg]: self‐directed = −0.7 (−1.2, −0.1); My Way = −1.9 (−2.5, −1.3); Turbo 10 = −1.9 (−2.4, −1.3); NS‐DASH −1.8 (−2.3, −1.4); p < 0.05 for all] and at 16 weeks [self‐directed = −1.2 (−2.1, −0.4); My Way = −4.5 (−5.8, −3.3); Turbo 10 = −4.4 (−5.7, −3.1); NS‐DASH −4.1 (−5.2, −3.0); p < 0.05 for all]. Similarly, total body circumference was significantly reduced at 4 weeks [mean difference from baseline (95% CI) in cm]: self‐directed = −3.7 (−5.6, −1.7); My Way = −9.4 (−11.5, −7.3); Turbo 10 = −10.7 (−12.5, −9.0); NS‐DASH −9.0 (−11.1, −6.9); p < 0.05 for all] and at 16 weeks [self‐directed = −5.8 (−9.0, −2.6); My Way = −17.2 (−21.7, −12.7); Turbo 10 = −16.9 (−21.5, −12.3); NS‐DASH −14.3 (−18.3, −10.2)]. The reductions in body weight, total fat mass, and total body circumference associated with each Nutrisystem intervention at 4 and 16 weeks were larger than corresponding changes in response to the self‐directed diet (p < 0.05 for each comparison). Additionally, more subjects in the My Way (56.1%), Turbo 10 (57.9%), and NS‐DASH (61.0%) groups lost ≥ 5% of initial body weight, compared to subjects assigned to the self‐directed diet (13.2%) (p < 0.001 ). In conclusion, each Nutrisystem intervention resulted in greater weight loss, body fat loss, and reduction in total body circumference compared to a self‐directed DASH diet over a 16‐week study period.Support or Funding InformationFunded by Nutrisystem, Inc.