Purpose: Repeated weight loss followed by weight gain may cause women to become metabolically efficient and therefore regain weight after dieting. The aim of this study is to investigate what effect long term weight cycling has on metabolic function and eating behaviour in a normal weight population.
Method: Subjects were matched for body composition and grouped by previous weight fluctuates (weight cyclers) versus those who have remained weight stable (non-weight cyclers). Indirect calorimetry, 7-day nutritional intake and activity, three-factor eating questionnaire and a DEXA scan were performed.
Results: There were no significant differences in resting metabolism, however the weight cyclers were lower (4.8 ± 1.0 versus 5.0 ± 1.1 MJ/day). Restrained eating and disinhibition were different between non-weight cyclers (3.9 ± 2.9; 5.1 ± 2.2) and weight cyclers (6.7 + 3.7, p=0.04; 7.8 ± 3.7, p=0.03; respectively). Self reported daily activity was higher (p=0.03) in the weight cyclers (1.7 ± 0.2) than the non-weight cyclers (1.5 ± 0.2).
Conclusions: Resting metabolic rate did not differ between groups, however will power, resistance to eating cues and daily activity levels did. Therefore, in order for subjects who have dieted to obtain the same body composition they must have compensatory psychological and physical behaviours.