Modulating food craving-related neural oscillations using tACS: study protocol for a randomized sham-controlled trial

Abstract

Introduction: Food addiction is characterized by heightened craving and impaired inhibitory control, contributing to compulsive eating and obesity. Existing behavioral and pharmacological interventions often fail to achieve lasting effects. Transcranial alternating current stimulation (tACS), by modulating neural oscillations and connectivity, offers a novel, non-invasive approach for regulating craving-related neural circuits.

Objectives: This study aims to evaluate the effects of fixed-frequency tACS targeting the dorsal lateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC), and insula on food cravings, inhibitory control, and related neural oscillations. The trial will assess whether tACS can reduce craving intensity and enhance inhibitory performance in individuals with varying degrees of food addiction severity.

Methods: We will conduct a randomized, double-blind, sham-controlled trial involving 175 participants aged 20-55 years, stratified by food addiction status (FA+ vs. FA-) using the Yale Food Addiction Scale (YFAS 2.0). Participants will receive tACS at alpha (10 Hz) or theta (6 Hz) frequency over the DLPFC, ACC, or insula for seven consecutive days. Electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) will be conducted pre- and post-intervention. Primary outcomes include changes in craving intensity and inhibitory control. Secondary outcomes include alterations in neural oscillations and functional connectivity.

Discussion: We hypothesize that theta-tACS over the ACC and insula will enhance inhibitory control and interoceptive awareness, while alpha-tACS over the DLPFC will improve top-down regulatory processes. This protocol aims to clarify the neural mechanisms underlying food cravings and evaluate tACS as a promising intervention for compulsive eating.

Keywords: DLPFC; anterior cingulate cortex; fMRI; food craving; insula; tACS.

FIGURE 1

Overview of the study timeline, including screening, intervention, and follow-up phases. This schematic illustrates the flow of participant activities and data collection across all phases of the study. Screening and baseline evaluations (Day 0) include eligibility verification, informed consent, structural MRI, and administration of behavioral questionnaires (YFAS 2.0, T-FCQ, CESD-R). The intervention phase (Days 1–7) involves daily tACS, with EEG performed on Days 1, 5, and 7, and behavioral assessments (S-FCQ, FCI, Go/No-Go task) performed on Days 1, 5, and 8. An fMRI will be performed post-tACS on Day 2. Post-intervention imaging (fMRI) and follow-up behavioral measures occur on Day 8. A follow-up assessment on Day 15 evaluates potential sustained effects and adverse events.