Why Some People Have More Willpower to Avoid Overeating

New research just published in the Journal of Neuroscience set out to discover if willpower was somehow related to neurobiology.

The research conducted by a group of researchers led by Hilke Plassmann, INSEAD associate professor of marketing, included four experiments involving 123 people—78 women and 45 men. It is noted that this is a small study. In the first three, participants were placed inside an fMRI scanner, shown photos of food items and asked whether they wanted to consume them, with response options ranging from “strong yes” to “strong no." They were further instructed to base their decisions either on health, tastiness or their own natural inclinations. The items depicted ranged from Brussels sprouts to chocolate chip cookies.

In the fourth experiment, they instructed participants to “indulge” in the food, “distance” themselves from taste-based cravings, or choose as they normally would. In lieu of the yes/no response, the fourth group was told to select the price they would pay to eat the food, on a scale from zero dollars to $2.50.

Analyzing the test subjects’ brain anatomy alongside their food choices, they  found that the level of self-control they exhibited—that is, their ability to focus on health and de-emphasize taste when instructed to do so—was predicted by the grey matter volume (GMV) in two brain regions. Those with higher GMV in the dorsolateral prefrontal cortex (dlPFC) and ventromedial prefrontal cortex (vmPFC) displayed more self-control.

Their theory based on past research as well is that the vmPFC is involved in the integration of various attributes such as healthiness and tastiness into a holistic value signal, and the dlPFC implements the self-control.

The researchers stress that this does not mean that all is lost if your brain acts this way—rather that the GMV is “like a muscle that can be developed with exercise”—that the structure of brain regions can change based on use as well as a host of other circumstances, an adaptive capacity known as “neuroplasticity.” 

Topline is that neurofeedback modalities targeting the vmPFC and dlPFC—if and when they are perfected—could potentially help people with self-control issues improve their eating habits and even help in the treatment of food disorders linked to dysfunctional self-control behavior such as anorexia and binge eating.