Effects of diet cycling on weight loss and resting energy expenditure in women participating in the Curves® fitness program

This study examined the efficacy of cycling diet phases in order to promote weight loss and maintenance of REE. 44 sedentary women (34±7 yrs, 89±19 kg; 43±5% body fat) were assigned to a high carbohydrate (HC, n=25) or high protein (HP, n=19) diet group. During the first 30‐days, subjects consumed 1,200 kcals/d for 1‐wk followed by ingesting 1,500 kcals/d for 3‐wks. Subjects then followed a 2,200 kcals/d maintenance diet for 4 wks and then repeated the 30‐day diet. Diets were 45% CHO, 30% PRO, and 25% F or 45% PRO, 30% CHO, and 25% F. Subjects participated in the Curves circuit training program 3‐d/wk and walked for 30‐min 3‐d/wk. Data were analyzed by repeated measures ANOVA and are presented as means ± SD changes from baseline after 1, 2, & 3 months for the HC and HP groups, respectively. Significant time effects (p=0.001) were observed in weight loss and fat loss with no differences between types of diets in weight loss (HC −3.7±4.3, −5.4±5.5, −7.2±7.6; HP −5.8±4.9, −7.3±5.8, −8.9±6.6, lbs Q p=0.12) and fat loss (HC −3.1±3.5, −5.0±4.4, −5.4±4.9; HP −3.5±3.6, −5.6±4.6, −7.0±5.1 lbs, p=0.33). Mean REE values declined and rebounded over time (Q p=0.01) with no differences between groups (HC −0.92±2.5, −0.83±3.1, −0.33±3.0; HP −0.39±2.1, −0.76±2.4, 0.09±2.4 kcal/kg/d, p=0.78). Results suggest that following 30‐day cycles of dieting/maintenance can promote weight loss while maintaining REE.