Researchers at the Garvan Institute of Medical Research in Sydney have found that the relationship between stress and overeating, especially high-calorie comfort food, leads to weight gain. This study revealed that stress suppresses the brain’s natural response to satiety, particularly in the lateral habenula region of the brain, triggering persistent reward signals that promote the intake of highly palatable foods. Furthermore, they identified the molecule NPY, which is naturally produced by the brain in response to stress, as a central player in this process.
Scientists have found that when a high-calorie diet is combined with stress, the brain’s reward signals for food intake increase, leading to weight gain. They attribute this to the molecule NPY produced under stress and to suppression of the satiety response in the lateral habenula part of the brain. The study emphasizes maintaining a healthy diet to prevent overeating during times of stress.
High-calorie snacks can seem soothing when you’re stressed. However, this combination has an unhealthy downside. Scientists in Sydney say that stress combined with high-calorie “comfort” foods can make you eat more, increase cravings for sweet and savory foods, and trigger changes in your brain that lead to excessive weight gain. is said to be caused by
A team at the Garvan Institute of Medicine found that stress overrides the brain’s natural response to satiety, triggering non-stop reward signals that encourage eating more palatable foods. This occurs in a part of the brain called the lateral habenula nucleus, which, when activated, usually dampens these reward signals.
“Our findings reveal that stress can override the natural brain response that reduces the pleasure derived from eating. “It means that we can obtain a high-quality product,” said Professor Herzog, a senior author of the study and a visiting fellow at the Garvan Institute.
“When chronic stress is combined with a high-calorie diet, we tend to eat more and more and prefer sweet, highly palatable foods, which can promote weight gain and obesity.” This study highlights how important a healthy diet is during times of stress.”
The study was published in a journal neuron.
From brain stress to weight gain
Some people eat less when they’re stressed, but most people eat more than they normally would and choose high-calorie foods high in sugar and fat.
To understand the causes of these dietary habits, the researchers used mouse models to investigate how different regions of the brain respond to chronic stress under different diets.
“We have found that the region known as the lateral habenula nucleus, which is normally involved in switching off the brain’s reward response, is activated in mice given a short-term high-fat diet to protect the animals from overeating. However, when mice were chronically stressed, this part of the brain remained silent, allowing reward signals to remain active and encouraging eating for pleasure. It stops responding to satiety-regulating signals,” explains Dr. Kenny Chee Kin Yip, lead author of Garvan. Institute.
“We found that mice stressed with a high-fat diet gained twice as much weight as unstressed mice fed the same diet.”
Researchers have discovered that at the heart of weight gain is a molecule called NPY, which the brain produces naturally in response to stress. When researchers found that NPY blocked activation of brain cells in the lateral habenula nucleus of stressed mice fed a high-fat diet, the mice consumed less comfort food and consequently lost weight. .
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The researchers then conducted a “sucralose preference test,” asking the mice to choose between drinking water or artificially sweetened water.
“Mice stressed with a high-fat diet consumed three times more sucralose than mice fed only a high-fat diet, suggesting that stress activates more rewards when eating. not only, but also trigger cravings, especially for sweet and savory foods,” says the professor. Herzog.
“Importantly, we did not see this preference for sweetened water in stressed mice on a normal diet.”
Stress Disrupts Healthy Energy Balance
“In stressful situations, it is easy to expend a lot of energy, and the feeling of reward can be soothing. Experience seems to change the equation and encourage eating that is bad for you in the long run,” says Herzog.
The researchers say their findings identify stress as a key dietary regulator that can override the brain’s natural ability to balance energy needs.
“This study highlights how stress can impair healthy energy metabolism,” says Herzog. “This is a reminder to avoid a stressful lifestyle, and if you’re dealing with long-term stress, it’s important to try to eat healthy and stay away from junk food. ”
REFERENCES: “Critical role of the lateral habenula nuclear circuit in the regulation of stress-induced palatable food intake” Chi Kin Ip, Jemma Rezitis, Yue Qi, Nikita Bajaj, Julia Koller, Aitak Farzi, Yan-Chuan Shi, Ramon Tasan, By Lei Zhang and Herbert Herzog, 8 June 2023, neuron.
DOI: 10.1016/j.neuron.2023.05.010
This study was supported by the National Health and Medical Research Council (project grant 1066809). Professor Herzog is a Co-Professor at the St. Vincent Clinical School of Medicine and Health, Sydney, New South Wales. Dr. Kenny Chi Kin Ip is Co-Lecturer at the School of Medicine and Health, St. Vincent Clinical School, UNSW Sydney.
