Neuromodulation targeted to the prefrontal cortex induces changes in energy intake and weight loss in obesity

Abstract

Objective: Obesity is associated with decreased activity in the prefrontal cortex. Transcranial direct current stimulation (tDCS) modifies cortical excitability and may facilitate improved control of eating. The energy intake (EI) and body weight in subjects who received cathodal versus sham (study 1) and subsequent anodal versus sham (study 2) tDCS aimed at the left dorsolateral prefrontal cortex (LDLPFC) were measured.

Methods: Nine (3m, 6f) healthy volunteers with obesity (94 ± 15 kg [M ± SD]; 42 ± 8 y) were admitted as inpatients for 9 days to participate in a double-blind, randomized, placebo-controlled crossover experiment. Study 1: following 5 days of a weight-maintaining diet, participants received cathodal or sham tDCS (2 mA, 40 min) on three consecutive mornings and then ate ad libitum from a computerized vending machine, which recorded EI. Weight was measured daily. Study 2: participants repeated the study, maintaining original assignment to active (this time anodal) and sham.

Results: Participants tended to consume fewer kilocalories per day (P = 0.07), significantly fewer kilocalories from soda (P = 0.02) and fat (P = 0.03), and had a greater % weight loss (P = 0.009) during anodal versus cathodal tDCS.

Conclusions: The results indicated a role for the LDLPFC in obesity and food intake. This proof of concept study suggested, for the first time, the potential application of anodal tDCS to facilitate weight loss.

Conflict of interest statement

Conflict of Interest: The authors declare no conflict of interest.

© 2015 The Obesity Society.

Figures

Figure 1. Change in energy intake after cathodal (Study 1) and anodal (Study 2) stimulation

1. Participants who received active tDCS tended to consume fewer total kcal/d (Δ= −692±632 kcal/day, p=0.07, Figure 1a) during anodal vs. cathodal stimulation and as % of WMEN (Δ= −23±25 %, p=0.11, Figure 1B) during anodal vs. cathodal stimulation

2. Participants who received active tDCS consumed significantly fewer kcals from fat (Δ= −337±234 kcal/day, p=0.03, Figure 1C) and soda (Δ= −66±42 kcal/day, p=0.02, Figure 1D) but not from total carbohydrates (Δ= −719±850 kcal/day, p=0.13, Figure 1E) during anodal compared to cathodal stimulation

Figure 2. % body weight change after cathodal (study 1) and anodal (study 2) stimulation

% weight change was significantly different following the 3 day ad libitum intake period after anodal vs. cathodal stimulation (study 1: +0.6 ± 1.2% vs. study 2: −0.2 ± 1.5%; Δ= −0.9 ± 0.4%, p=0.009)