2023-06-19 13:43:43
Intestines talk to the brain
When we ingest food, the intestines send signals to the brain to indicate that there is food in the digestive tract. This keeps us from overeating.
But one research at Yale University in Connecticut, USA shows that this signal exchange leads to changes in brain activity in lean people, but hardly works in obese people.
The difference in brain activity may explain why it is so difficult for some people to lose weight and maintain it.
Tasting with fat and sugar
Using an intravenous drip, the researchers studied the effect of introducing sugar or fat directly into the digestive tract of 28 slim subjects (BMI of 25 or less) and 30 obese subjects (BMI of 30 or more). Immediately afterwards, they measured brain activity with functional magnetic resonance imaging (fMRI).
In the slim participants, there was reduced activity in several brain regions in response to both fat and sugar. But they measured no changes in brain activity in the obese participants.
“This surprised us. We thought there would be a measurable difference between lean and obese people, but we didn’t realize there was no change at all in brain activity in the obese,” said Mireille Serlie, a professor of medicine at the Yale School of Medicine, who led the study. led.
Your brain rewards you
Together with the research team, she decided striatum closer look: a part of the brain that is connected to our reward system, which is partly controlled by the neurotransmitter dopamine.
She used fMRI to see how the brain reacted to sugar and fat respectively. In slim participants, both sugar and fat led to decreased activity in two parts of the striatum. In obese participants, only sugar changed activity — and only in one part of the striatum.
In other words, their bodies were significantly less able to respond to food intake.
No change after weight loss
It became especially interesting when the obese people were asked to follow a 12-week weight-loss program. The participants who managed to lose at least 10 percent weight were then reassessed.
Surprisingly, the weight loss did not positively affect the brain’s ability to respond to food intake.
The researchers will use this new knowledge to investigate why some people have such difficulty controlling their eating behaviour.
“We need to identify the point at which the brain begins to lose its ability to regulate food intake, and what causes it. If we know where and when this happens, we can better intervene preventively,’ explains Mireille Serlie.
#people #control #eating #behavior