We’ve all heard it: If you’re overweight, you need to eat less. But we also know that that’s easier said than done. Interestingly, according to new study, the ability to curb the appetite may all be in your head.
According to researchers Dr. Dhillo and colleagues at Imperial College London, it’s the brain that makes us feel hungry and full. Brain activity increases as we anticipate our next meal, and decreases after we’ve eaten. Science has already shown that the hormones PYY and GLP-1 enter the bloodstream soon after eating and seem to play a role in this effect, so Dr. Dhillo and his team conducted a study in which patients took PYY and GLP-1 to see if they would eat less.
The researchers looked at brain activity using MRI scans of patients who were shown images of food in two different scenarios: (1) in a fasting state with a dose of the hormones, before eating and (2) with a full belly before sitting down to a second meal. In both scenarios, they found similar levels of brain activity: A decrease in areas known to control appetite behavior (ie, the hormones sent a signal to the brain similar to the signal sent by a meal). The result? Even though patients had not eaten in the first scenario, the brain activity indicated that they had. When they sat down to their meal, they subsequently ate less.
According to Dr. Dhillo, their results confirm that PYY and GLP-1 are important influencers of fullness and may have potential for treating the obesity epidemic and also encourage healthier eating.