Images of high-calorie food create craving

Viewing images of high-fat foods and drinking sweetened beverages lights up the appetite and reward centres in the brain.

“Studies have shown that advertisements featuring food make us think of eating, but our research looked at how the brain responds to food cues and how that increases hunger and desire for certain foods,” said Kathleen Page, the principal study investigator.

“This stimulation of the brain’s reward areas may contribute to overeating and obesity, and has important public health implications,” said Page, professor of clinical medicine at the Keck School of Medicine at University of Southern California.

Page and colleagues used functional magnetic resonance imaging (fMRI) to measure the brain responses of obese, Hispanic adolescent women aged between 15 and 25 years, according to a California statement.

Women were chosen because prior research indicates they were more responsive to food cues; the study group was narrowed to Hispanic women because of the high risk of obesity and type 2 diabetes in the community.

The women’s brain responses were scanned twice as they looked at pictures of high-calorie foods, such as hamburgers, cookies, and cakes, and low-calorie foods such as fruits and vegetables. After seeing the high-calorie and low-calorie groupings, the participants rated their hunger and desire for sweet or savoury foods on a scale from one to 10.

Halfway through the scans, the women drank 50 gm of glucose — equivalent to a can of soda — and another time, they drank 50 gm of fructose. Glucose and fructose are the main components of table sugar and high-fructose corn syrup.

“We hypothesised that the reward areas in the women’s brains would be activated when they were looking at high-calorie foods, and that did happen,” said Page.

“What we didn’t expect was that consuming the glucose and fructose would increase their hunger and desire for savoury foods.”

The researchers also noted that fructose stimulated more hunger and desire in the participants’ brains than glucose did.

These findings were presented at the Endocrine Society’s annual meeting in Houston, Texas.