All-inclusive holiday Brits warned over booze and food or risk an ‘obese person’s brain’

Short-term over-consumption of sugar and fat triggers rapid changes in the brain of a healthy person, and they suddenly start thinking and behaving like an obese person, scientists found

Pigging out on holiday grub can leave folk with “obese brain,” boffins warn.

Research has shown over-indulging for just a few days triggers a rapid mind change that makes healthy people behave like fatties. That is why folk struggle to shift weight when they get home from a holiday. The mental impact of tucking into the midnight chocolate buffet can last longer than any physical symptoms.

A new study has found that while holidaymakers may bemoan putting on a few pounds from a week or two of all-inclusive food and drink the real damage is done between the ears.

Short-term over-consumption of sugar and fat triggers rapid changes in the brain of a healthy person. They suddenly start thinking and behaving like an obese person, scientists found.

The brain changes last longer and are slower to return to normal than any impact the food has on the body itself.

Professor Stephanie Kullmann, of the University of Tubingen, Germany, who led the study, said: “The changes in the brain outlasted the timeframe of the consumption. Behaviorally we see that participants show changes in reward behaviour – reduced reward sensitivity.

“This could lead to greater food intake. Our data indicate that the brain and behaviour response resemble that of a person with obesity and changes in the brain seem to occur prior to weight gain.’’

Scientists gave 18 young and healthy men a high-calorie diet filled with sugary and fatty foods for five days – including chocolate bars, brownies, biscuits, salami and crisps. The aim was to increase food intake by 1,500 calories above normal.

The men put on no weight, the study found, but there was a substantial change in their brain thought to have been caused by the diet. Five days of extra sugar and fat was enough to make their brains behave like those of an obese person, the scientists found.

Brain tests were done before, immediately after and a week on from the five-day high-calorie diet and showed changes after eating a poorer diet. The men’s brains had higher levels of resistance to insulin for up to a week after the fatty diet ended compared to a control sample.

Insulin is produced in the body to help turn food into energy. Some insulin goes to the brain to suppress appetite.

Resistance to the hormone in the brain occurs in response to high levels of sugar exposure and can lead to persistent hunger and a lack of feeling full – making it easier to put on weight.

Data from the study showed the changes caused by diet were longer lasting in the brain than in the rest of the body.

While the diet change altered some biological pathways they returned to normal quickly, the scientists found. Whereas the impact of insulin resistance in the brain was still present a week after finishing the fatty diet.

The scientists wrote in the study, published in Nature Metabolism: “The current study demonstrates that brain insulin responsiveness adapts to short-term dietary changes after overconsumption of broadly available sweet and fatty ultra-processed snacks in addition to their regular diet, in healthy weight men, in the absence of changes in body weight, peripheral insulin sensitivity and food craving.”

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