Analysis of efficacy and cost effectiveness of popular weight loss and fitness programs

Methods 127 sedentary women (47±11 yr, 45.8±5% body fat, 35.4±5 kg/m) were randomized to participate in a no diet or exercise control group (C) or the Curves Complete 90-day Challenge (CC), Weight Watchers Points Plus (WW), Jenny Craig (JC), or Nutrisystem Advance SelectTM (NS) weight loss programs for 12-wks. Participants in the diet groups were encouraged to exercise (WW, JC, NS) while those in the CC group participated in a structured circuit-style resistance training (3 d/wk) and walking (3/d wk) program. Program and food cost were calculated for a random sample of 1 week for 10 participants for each group. Food costs were estimated based on determining the cost of purchasing foods described in diet logs reported by the participants. These costs were averaged and applied to each subject for the duration of the study. The cost per day (C 4.7±2.2, CC 6.4±1.6, WW 4.9±1.4, JC 2.2±1.1, NS 1.8±1.1 $/day), was used to calculate an average 90 day food cost (C 422±198, CC 579±147, WW 438±130, JC 200±101, NS 162±103 $/90day). This was added to the program participation costs (C 0, CC 300, WW 120, JC 2,400, NS 900 $/90day) to estimate a total cost (C 422±198, CC 879±147, WW 558±130, JC 2,600±101, NS 1,062±103 $/90day) per program. Measurements were taken for body composition, fitness, and health measures. The changes in these variables were then divided by the overall cost for each program to establish the cost effectiveness for each program. Changes from baseline after 12-wks intervention for weight, waist circumference, hip circumference, bone mineral content, fat mass, fat-free mass, and peak oxygen uptake were analyzed by one-way ANOVA.