Watching others enjoy good food can cause overeating: study | Health

By Stephen Beech

Watching other people tuck into tasty food may trigger overeating, suggests new research.

Seeing others enjoying a good feed can bring about binge eating – even in the absence of hunger, according to the study.

The findings could help develop new ways of treating eating disorders, say American scientists.

Study senior author Professor Yong Xu said: “This animal model opens the door to developing new treatments that target the brain’s reward system to help prevent or reduce overeating.

“It also supports public health efforts that aim to limit the influence of visual food cues in media and social settings, which could help people better manage their weight and eating habits.”

The research team divided 14 mice into two groups for the study.

One group was either fed or fasted overnight before testing, while the second group was always fed before testing.

The mice were paired based on genetic and parental information and placed in separate but nearby areas to observe each other without physical contact.

The research team measured the amount of food the mice ate hourly for four hours across different test days, using chow, high-fat, and sucrose diets.

In a follow-up experiment, the second group of mice received injections of either 0.1 ml of 9% saline, a D1 dopamine receptor (DRD1) inhibitor, or a D2 dopamine receptor (DRD2) inhibitor 15 minutes before testing, and food intake was measured.

The researchers found that satiated mice that watched their fasted peers eat did not consume more chow or high-fat food.

However, they “significantly” increased their intake of the sucrose diet during the first hour of observation, both in the initial and repeated experiments.

The overeating persisted after saline injections but was suppressed by dopamine receptor inhibitors.

Xu, of Baylor College of Medicine in Houston, Texas, said: “This study shows, in animals, that simply watching another eat – especially palatable food – can cause overeating, even when not hungry.

“It also identifies a specific brain system – dopamine signalling – that helps explain why this happens.”

He added: “This type of behaviour, driven by environmental and social cues, is very relevant in today’s world, where food is abundant and eating shows or food-related social media are common.”

The researchers suggest that recognising the pattern may help people become more aware of overeating, a major factor in obesity, and open the door for new treatments.

The findings were presented at the Endocrine Society’s annual meeting in San Francisco, California.