Neuromodulation directed at the prefrontal cortex of subjects with obesity reduces snack food intake and hunger in a randomized trial

Abstract

Obesity is associated with reduced activation in the left dorsolateral prefrontal cortex (DLPFC), a region of the brain that plays a key role in the support of self-regulatory aspects of eating behavior and inhibitory control. Transcranial direct current stimulation (tDCS) is a noninvasive technique used to modulate brain activity. We tested whether repeated anodal tDCS targeted at the left DLPFC (compared with sham tDCS) has an immediate effect on eating behavior during ad libitum food intake, resulting in weight change, and whether it might influence longer-term food intake-related appetite ratings in individuals with obesity. In a randomized parallel-design study combining inpatient and outpatient assessments over 31 d, 23 individuals with obesity [12 men; mean ± SD body mass index (BMI; in kg/m): 39.3 ± 8.42] received 15 sessions of anodal (i.e., enhancing cortical activity) or sham tDCS aimed at the left DLPFC. Ad libitum food intake was assessed through the use of a vending machine paradigm and snack food taste tests (SFTTs). Appetite was evaluated with a visual analog scale (VAS). Body weight was measured. We examined the effect of short-term (i.e., 3 sessions) and long-term (i.e., 15 sessions) tDCS on these variables. Relative to sham tDCS, short-term anodal tDCS did not influence ad libitum intake of food from the vending machines. Accordingly, no effect on short-term or 4-wk weight change was observed. In the anodal tDCS group, compared with the sham group, VAS ratings for hunger and the urge to eat declined significantly more ( = 0.01 and = 0.05, respectively), and total energy intake during an SFTT was relatively lower in satiated individuals ( = 0.01), after long-term tDCS. Short-term anodal tDCS of the left DLPFC did not have an immediate effect on ad libitum food intake or thereby weight change, relative to sham tDCS. Hunger and snack food intake were reduced only after a longer period of anodal tDCS in individuals with obesity. This trial was registered at clinicaltrials.gov as NCT00739362.

Real-time fMRI neurofeedback training to improve eating behavior by self-regulation of the dorsolateral prefrontal cortex: A randomized controlled trial in overweight and obese subjects

“…This pattern was reflected by a reduction in the number of "yes" decisions for high-calorie food items that received very high palatability ratings. Taken together, these results, which are in line with beneficial effects on eating behavior of transcranial direct current stimulation of dlPFC activity in obese subjects (Gluck et al, 2015;Heinitz et al, 2017;Montenegro et al, 2012), suggest improved self-control during food choices after the neurofeedback intervention in our obese and overweight individuals. While we did not observe significant correlations between selfregulation performance in individual training ROIs with pre-post differences in body weight, body fat, or behavioral outcomes, the strong correlation between the decrease in palatability ratings and functional connectivity-derived dlPFC-right insula regulation provides a direct link between training-induced neural changes and improvements in food intake control.…”

Obesity and Related Type 2 Diabetes: A Failure of the Autonomic Nervous System Controlling Gastrointestinal Function?

“…The left dorsolateral prefrontal cortex (DLPFC), which is part of the dorsal cognitive fronto-striatal circuit, exerts cognitive control over food intake [38]. Obesity is associated with a reduced activation of this brain region [61]. Its postprandial activation is significantly inferior in the obese compared to in the lean [62].…”

Brain stimulation for treatment of obesity: will stimulating the prefrontal cortex reduce overeating?

“…The primary findings reported in Heinitz et al (3) are that stimulating the neurons in the left DLPFC reduced snack intake and self-reported hunger after an extended 4-wk stimulation period compared with sham treatment. However, no change was reported immediately after 3 sessions of tDCS on 3-d ad libitum intake assessed with a validated vending machine protocol.…”

“…Second, do we understand the role of the DLPFC in driving overconsumption? Heinitz et al (3) found no effect on 3-d ad libitum food intake assessed by a validated vending machine paradigm. The foods included in the vending machine were those that had "intermediate" preference ratings as indicated by a food preference questionnaire.…”

“…Despite these findings, we do not know if low neuronal firing in this region is a cause or consequence of obesity. The reasonable hypothesis made by Heinitz et al (3) is that stimulating the left DLPFC will enhance dietary self-control and, as a result, reduce overconsumption. However, this assumes that low DLPFC activity is a cause of overeating.…”