The Effects of Low-Carbohydrate Diets on Psychosocial Outcomes in Obesity/Overweight: A Systematic Review of Randomized, Controlled Studies

BACKGROUND Little is known about the relative psychosocial effects of carbohydrate reduction in comparison to other weight-loss diets in subjects receiving treatment for obesity/overweight. We, therefore, set out to conduct a systematic review of the psychosocial outcomes of such patients, treated by means of either a low-carbohydrate diet or an isocaloric diet of other macronutrient composition. METHODS Literature searches, study selection, method development, and quality appraisal were performed independently by two authors, and data were synthesized using a narrative approach, in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. RESULTS Eight randomized controlled studies met the inclusion criteria, and their subsequent analysis revealed that improvements in psychological and social outcomes do occur during short- and long-term weight loss programmes, but that low-carbohydrate diets have no greater effect on psychosocial outcomes when compared to diets of different macronutrient composition at either short- or long-term follow-up (one-year). However, the lack of studies with longer duration follow-up, and the absence of data in the adolescent population limit the generalizability of our findings. CONCLUSION The short- and long-term improvements in psychosocial outcomes seen in patients undergoing weight-loss treatment appear to be independent of the macronutrient composition of their diet.