The effect of transcranial direct current stimulation along with a hypocaloric diet on weight loss in excessive weight people: A pilot randomized clinical trial

Background & aims The dorsolateral prefrontal cortex plays an important role in the desire to eat and food intake regulation and may be a target for transcranial direct current stimulation (tDCS) to promote weight loss. Our aim was to test the effect of repeated, active tDCS along with a hypocaloric diet (HD) on weight loss in overweight adults. Methods This was a randomized, placebo-controlled, double-blind pilot study conducted in Porto Alegre, Brazil. Twenty-eight overweight adults were selected to receive 4-week (20 sessions, t0 to t20; 5 weekdays) fixed-dose tDCS along with an HD. Subjects were randomly assigned to active (AG) or sham (SG) tDCS groups. The primary outcome was weight loss as determined via body weight measurements at baseline (t0), weekly (t5, t10, t15, and t20), and after the intervention (tF). A visual analogue scale was used to assess desire to eat at t0 and at tF. Registered under ClinicalTrials.gov Identifier no. NCT02683902. Results Although there was a greater weight loss in the AG (mean -4.5 kg [95%CI: -9.4, 0.5]) than in the SG (-2.3 kg [-5.0, 0.3]), this difference was not statistically significant. However, the AG showed a significant reduction in the desire for sweet foods (P = 0.005). Conclusions Although this pilot study did not show that repeated tDCS is able to optimize weight loss, it was able to reduce the desire to eat sweet foods. These findings suggest that a protocol with a larger sample size could determine whether tDCS may be an adjunctive treatment of obesity.