by Laura Cuppini
Stress, combined with a high-calorie diet, leads to a preference for sweet and highly palatable foods, thus promoting weight gain
Stress, especially if prolonged, can lead to wrong food choices, with the risk of ending up overweight. This is demonstrated by a study by the Garvan Institute of Medical Research in Darlinghurst (Australia), published in the journal Neuron. According to the authors, stress coupled with high-calorie comfort food creates changes in the brain that lead to overeating, increases cravings for sweet and highly palatable foods, and can lead to excessive weight gain. This happens because stress overrides the brain’s natural response to satiety by interfering with the activity of an area called the lateral habenula. Our study shows that stress can cancel out a brain response that limits the desire to eat, thus favoring the search for a continuous reward in food – said Herbert Herzog, senior author of the study -. Chronic stress, combined with a high-calorie diet, can push you to prefer sweet and highly palatable foods. Our research highlights how crucial a healthy diet is during times of stress.
The experiment
There are those who are less hungry in times of stress, but most people eat more than usual and choose products rich in calories, sugars and fats. To understand the origins of these food choices, the Australian team studied in mice how different brain areas respond to chronic stress, in the face of various diets. We found that an area known as the lateral habenula, normally involved in shutting down the brain’s response to reward, was active in mice fed a short-term high-fat diet. However, when the mice were chronically stressed, this part of the brain remained silent, allowing reward signals to remain active, no longer responding to satiety regulatory signals, explained first author Chi Kin Ip. We found that stressed mice fed a high-fat diet gained twice as much weight as unstressed mice fed the same diet. According to the researchers it all depends on the neuropeptide Y (Npy), which the brain produces naturally in response to stress. When the researchers blocked the activation of lateral habenula cells in stressed mice that ate a high-fat diet, the mice ate less food, resulting in less weight gain.
Water with sweetener
The researchers then performed a further test, allowing the mice to choose whether to drink water or water to which a sweetener (sucralose) had been added. Stressed mice fed a high-fat diet consumed three times as much sweetener as mice fed only a high-fat diet, suggesting that stress not only triggers greater reward when eats, but specifically pushes to desire sweet and palatable foods – commented Herzog -. In contrast, we did not see this preference for sugar water in stressed mice on a regular diet. In stressful situations we tend to consume a lot of energy and the feeling of reward can be calming: in these cases it is useful to receive an energy boost from food. But, if sustained, stress seems to change the equation, prompting long-term unhealthy eating. Therefore, according to the researchers, stress is a regulator of eating habits that can override the brain’s natural ability to balance energy needs. This work underlines how much stress can compromise a healthy energy metabolism – concluded Herzog -. If you suffer from prolonged stress, it is crucial to eat a healthy diet and avoid junk food.”
June 26, 2023 (change June 26, 2023 | 08:17)
© breaking latest news