Multisession transcranial direct current stimulation and aerobic exercise synergistically improve food craving symptoms, impulsivity, and cognitive flexibility in women with overweight and obesity : a randomized controlled trial

Abstract

Background: We explored the potential synergistic effects of combining multisession anodal transcranial direct current stimulation (a-tDCS) with chronic aerobic exercise (AE) on food cravings (FC), impulsivity (IMP), risky decision-making (RDM), and cognitive flexibility (CF) in women with overweight or obesity exhibiting food craving symptoms. Methods: Thirty-six women with overweight or obesity and symptoms of food craving (age: 26±6,4 years) were randomly allocated into three groups using permuted block randomization (n = 12 each): (1) a-tDCS + AE, (2) Sham + AE, and (3) Control (no intervention). During Phase 1, the a-tDCS + AE group received five consecutive sessions of a-tDCS, while the Sham + AE group received sham tDCS. In Phase 2, both the a-tDCS + AE and Sham + AE groups completed three sessions of moderate-intensity continuous aerobic exercise per week for four weeks. Outcome measures, including food cravings (FC) and cognitive flexibility (CF), were assessed at baseline, after five days of tDCS, and after four weeks of AE. Follow-up measurements for FC and CF were also conducted one month post-intervention. Results: FC was lower in the a-tDCS + AE group compared to Sham + AE and Control groups in Phase 1 (Cohen’s d = 1.4 and 1.9, respectively). In Phase 2, a-tDCS + AE and Sham + AE groups showed lower FC than the Control group (d = 3.8 and d = 2.8, respectively), and a-tDCS + AE also showed a lower FC compared to the Sham + AE group (d = 1.5). FC remained lower in the a-tDCS + AE group compared to Sham + AE and Control groups at follow-up (d = 1.7 and d = 2.4, respectively). CF was higher in the a-tDCS + AE compared to Sham + AE and Control groups (d = 2.1 and d = 1.4, respectively) and in the sham + AE (d = 1.0) compared to control in Phase 2. At follow-up, CF was higher only in the a-tDCS + AE group compared to the Control (d = 1.2). IMP scores were higher in the a-tDCS + AE group compared to the other groups in Phases 1 (d = 1.0 and d = 1.4) and 2 (d = 5.4 and d = 1.9). RDM was higher in the a-tDCS + AE compared to the Control group in phase 2 (d = 1.3). Conclusions: Multisession a-tDCS combined with four weeks of moderate AE synergistically reduces food cravings and improves related variables to a greater extent than AE alone, with sustained effects, in women with overweight or obesity and symptoms of food craving. Trial registration: This study was registered in the Iranian Registry of Clinical Trials (IRCT id: IRCT20210617051606N7; Registration date: 04.02.2023).