Abstract: Reinforcing Relative Value (RRV) of food and impulsivity are associated with energy intake and obesity. This study investigated the degree to which changes in RRV and impulsivity independently or interactively predict changes in body weight and composition in women with overweight or obesity engaged in either fast or slow weight loss programs. Body weight, body composition, impulsivity (Barratt Impulsiveness Scale), and RRV snack (computerized Behavioural Choice Task) were measured at baseline and post-intervention in 30 women with obesity undergoing either slow (n = 14, –500 kcal/ day, 20 weeks) or fast (n = 16, –1000 kcal/day, 10 weeks) weight reduction. No group time effects were noted on body composition, impulsivity, or RRV, so participants from both groups were pooled for analysis. Multiple regression analyses indicated that none of the impulsivity variables predicted weight or fat mass (FM) loss. However, DRRV snack predicted DFM (r =0.40, p = 0.046), whereby greater increases in RRV snack were associated with less FM loss. The results indicate that different rates of weight loss do not differentially affect RRV snack or impulsivity traits. However, changes in RRV snack predicted FM loss, suggesting that dietary interventions that either mitigate increases or foster reductions in the RRV snack may yield greater reductions in adiposity. Trial Registration clinicaltrials.gov identifier: NCT04866875.
Senior Scientist, CHEO Research Institute