Weight loss maintenance in relation to locus of control: The MedWeight study

Locus of control, i.e. the degree of an individual's belief on the control of his/her life, has been related to many health outcomes, including weight loss in overweight/obese individuals. No information is available on the impact of locus of control in maintaining weight loss. We aimed to investigate the effect of locus of control in weight loss maintenance and explore potential associations with lifestyle factors. Study participants included 239 individuals (41% males) who had lost at least 10% of body weight in the past and either maintained the loss (maintainers: weight maintenance of at least 10% of initial weight) or regained it (regainers). Locus of control was defined by a relevant multi-dimensional scale; participants were categorised to internals and externals, based on "internal" and "others" sub-scales. A significant interaction was found between locus of control and weight loss maintenance status (p < 0.001), with internals being more likely to be maintainers. Regainers had a more external orientation, compared to maintainers. Weight loss methods differ between groups, with internals reporting loosing weight by themselves more frequently, while externals reporting loosing weight mainly with the aid of an expert. Weight cycling of 2-3 kg in a typical year was reported more frequently in internals. Total and vigorous physical activity, as well as total hobbies score were associated with an internal profile, while sedentary activities with an external profile. No differences were found in dietary intake between internals and externals. Our results suggest that weight loss maintenance is associated with an internal locus of control. Individualised treatment, according to locus of control, may increase weight loss maintenance rates in former overweight/obese individuals.