Maybe it’s not your stomach that is causing you to eat too much. Maybe it’s your brain.
Researchers at Rutgers Robert Wood Johnson Medical School in New Jersey said the lack of a specific hormone in the brain may cause some people to overeat. Their study was published today in the journal Cell Reports.
The researchers said their findings could change the focus of the causes of obesity and lead to new treatments.
But others cautioned that the study only looks at one aspect of overeating and does not take other important factors into consideration.
More Hormone, Less Food
In the study, researchers reduced levels of a hormone called glucagon-like peptide-1 (GLP-1) in the central nervous system of some laboratory mice. The mice with reduced levels of the hormone ate “beyond their need for calories” and consumed more high-fat food.
When scientists boosted hormone levels, the mice ate less and lost their preference for the high-fat choices.
The GLP-1 peptides are small sequences of amino acids. They’re supposed to tell the brain when we’ve eaten enough to sustain us. This allows the central nervous system to adapt to outside environments and control how much a body consumes, according to the researchers.
The GLP-1 hormone slows communications between neurons that would clamp down on reward behaviors such as overeating.
“These are the same areas of the brain that control other addictive behaviors like drug and alcohol abuse and nicotine addiction,” senior author Zhiping Pang, Ph.D., said in a press statement. “We believe that our work has broad implications in understanding how GLP-1 functions to influence motivational behaviors.”
The Causes of Overeating
The Rutgers scientists acknowledge there are other reasons why people overeat, but they said targeting these neurons might be a more effective way to curb obesity than current treatments.
“Overeating, which causes obesity, can be considered a food addiction, a neuropsychiatric disorder,” said Pang. “By finding out how the central nervous system regulates food intake behavior via GLP-1 signaling, we may be able to provide more targeted therapy with fewer side effects.”
But experts at the Global Obesity Prevention Center at the Johns Hopkins Bloomberg School of Public Health have tossed up a caution flag.
They said that just because a hormone change can cause overeating does not mean that most overeating is caused by hormones.
“Many other system causes may be leading to people eating more than they should, ranging from stress at work or school to peer pressure to cultural influences to advertising to the surrounding food environment,” said Dr. Bruce Lee, director of the center.
The Food and Drug Administration recently approved an injectable drug called Saxenda (liraglutide), which mimics the GLP-1 hormone, for the treatment of chronic weight management. However, the medication can cause serious side effects including pancreatitis, gallbladder disease, and kidney problems.
So at least for now, those trying to lose weight may be better off trying to focus on the social reasons for their overeating.