Effectiveness of Non-Invasive Brain Stimulation (NIBS) in Overeating and Increased Body Mass Index (BMI): An Umbrella Review.

This review of reviews aims to investigate the effectiveness of non-invasive brain stimulation (NIBS) methods, i.e., transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), in reducing elevated body mass index (BMI) and overeating behavior (food cravings, binge eating, increased food consumption). Systematic reviews and meta-analyses in the English language were included. A search was conducted in PubMed and EMBASE until January 2024. The quality of all included reviews was assessed using the "A Measurement Tool to Assess Systematic Reviews" (AMSTAR-2). Quality assessment and data extraction were conducted by two independent reviewers, while all reviewers participated equally in article synthesis. Twenty-four systematic reviews were included, most of which show promising results regarding the effectiveness of NIBS on overeating and increased BMI . For weight reduction, rTMS is more effective, and tDCS can improve food cravings and food consumption. However, the critically low quality of most included studies and the heterogeneity of the intervention parameters are strong limitations against drawing any safe conclusions. More studies are needed with stable NIBS parameters.