(NEW HAVEN, Conn.) -- The ability to fight food cravings may be all in your head, according to a new study published in the Journal of Clinical Investigation.
By manipulating blood sugar levels in study participants and monitoring their brains with functional MRI scanners, researchers from Yale University and the University of Southern California found that obese people had a more difficult time fighting off cravings for high-calorie foods, which could explain why it is difficult for obese people to lose weight.
The researchers showed pictures of high-calorie foods (including French fries and doughnuts) low-calorie foods (including tofu and salads) and non-foods to five obese and nine non-obese study participants.
When blood sugar levels were low in both obese and non-obese participants, the region of the brain associated with reward was activated, triggering a desire to eat high-calorie foods. Once the levels were brought back up to normal in the non-obese group, there was increased activity in the prefrontal cortex, the region of the brain involved in impulse control. The non-obese people were then less interested in the high-calorie foods.
This was not the case for obese participants. Not only was the desire for high-calorie foods more noticeable in their brain activity, but when their blood sugar levels were brought back up to normal, their brains continued to show a craving for high-calorie foods.
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