Efficacy of Commercial Weight Loss Programs on Metabolic Syndrome

Objective Commercial weight loss programs offer consumers a pre‐programmed means of managing weight. However, such programs differ in dietary advice and physical activity recommendations. The aim of this investigation was compare the Curves ® Complete 90‐day Challenge (CC), Weight Watchers ® Points Plus (WW), Jenny Craig ® At Home (JC), and Nutrisystem ® Advance Select™ (NS) on metabolic syndrome (MetS) and weight loss. Methods We examined 133 sedentary overweight women (47±11 yr, 86±14 kg, 35.4±6 kg/m 2 ) randomized into CC (n=29), WW (n=29), JC (n=27), NS (n=28), or control (n=20) for 12‐wks. Body mass and MetS were obtained at baseline and follow‐up (12 w). The primary outcome was MetS expressed as a categorical variable and summed z‐score (zMetS) as a continuous variable. Secondary outcomes included total caloric intake, body mass, respective anthropometry and measured physical activity (PA). Data were analyzed using a chi‐square and general linear model covaried for age and prevalence of MetS at baseline. Data are mean ± SD and mean change ± 95% CI when applicable. Results We observed significant reductions in total energy intake for all treatment groups except Control (−103 kcal, 95% CI, −277, 70): CC (−413 kcal, 95% CI, −573, −254), WW (−531 kcals, 95% CI, −675, −387), JC (−604 kcal, 95% CI, −753, −455), NS (−631 kcal, 95% CI, −778, −485). While post‐hoc analysis showed JC and NS to be greater than CC, weight loss was similar for all groups (−4.0 ± 4.2 kg). At baseline, the prevalence of MetS was: CC (35%), WW (31%), JC (37%), NS (39%) and control (45%). At follow‐up we observed a significant trend (p=0.008) in reduction of MetS prevalence such that CC (14%) and WW (28%) was significantly lower than JC (42%), NS (50%) and control (55%); however, WW was not significantly different than JC, NS, or control. When expressed as zMetS, only the CC group demonstrated a significant reduction in zMetS (−0.11, 95% CI −0.21, −0.004) vs. WW (−0.89, 95% CI −0.18, 0.02), JC (−0.05, 95% CI −0.16, −.06), NS (−0.06, 95% CI −0.16, 0.05) and control (−0.05, 95% CI, −0.18, 0.07). Other than exercise contained within the CC program, no significant changes were otherwise noted in total PA for any treatment group: CC (4645 MET min/week; 95% CI, −1638, 10929), Weight Watchers (−3361 MET min/week; 95% CI, 3208, 2988), Jenny Craig (−448 MET min/week; 95% CI, −6949, 6053), Nutrisystem (−967 MET min/week; 95% CI, −7401, 5468) or Control (5128 MET min/week; 95% CI, −2529, 12785). Conclusions Notwithstanding the minor differences in energy intake favoring JC and NS, each program demonstrated similar amounts of weight loss. However, a significant reduction in MetS was demonstrated only in CC and WW via categorical analysis and CC via zMetS. Thus, despite recommendations by each program to increase PA, the program including a structured fitness routine in conjunction with diet exhibited the greatest impact on changes in MetS.