The study was conducted by researchers at the University of Waterloo, Ontario, Canada. It included healthy young women that were selected because they reported strong and frequent cravings for chocolate and potato chips. These calorie-dense snack foods referred to as appetitive - are often implicated in the development of obesity.
The women were shown pictures of these foods to stimulate cravings. They also received a type of magnetic stimulation called continuous theta-burst stimulation to decrease activity in the dorsolateral prefrontal cortex (DLPFC) which studies suggest plays an active role in regulating food cravings.
According to the report: After stimulation of the dorsolateral prefrontal cortex, young women experience increased cravings for high-calorie snacks and eat more of those foods when given the opportunity. Following the theta-burst stimulation, the women reported stronger food cravings specifically for appetitive milk chocolate and potato chips. During a subsequent taste test they consumed more of these foods rather than alternative less-appetitive foods such as soda crackers and dark chocolate.
These findings shed a light on the role of the dorsolateral prefrontal cortex in food cravings specifically reward anticipation, which is the consumption of appealing high caloric foods and the relation between self-control and food consumption, says senior author Peter Hall, PhD. Stimulation to weaken DLPFC activity was also associated with lower performance on a test inhibitory control strength known as the Stroop Test. Decreased DLPFC activity appeared to be associated with increased reward sensitivity it made the participants more sensitive to the rewarding properties of palatable high-caloric foods.
The results also:
- highlight the role of executive function in governing dietary self-restraint, say the researchers. Executive function, which involves the DLPFC, refers to a set of cognitive functions that enable top-down control of action, emotion and thought.
- provide at the basic neurobiological level, direct evidence that the DLPFC is involved in one specific aspect of food cravings: reward anticipation. People with weak executive function may lack the dietary self-control necessary to regulate snack food consumption in the modern obesogenic environment. Faced with constant cues and opportunities to consume energy-dense foods, such individuals may be more likely to become overweight or obese.
- suggest that interventions aimed at enhancing or preserving DLPFC function may help to prevent obesity and related diseases. In conditions such as type 2 diabetes where healthy dietary habits are essential for effective disease control, interventions focused on enhancing DLPFC activity, through aerobic exercise and other means, may result in increased dietary self-control and subsequently improve disease management, Hall added.