The Brain-Obesity Connection: How Stress and High-Calorie Intake Fuel Overeating and Cravings for Sweets

A study has found that eating high-calorie foods while suffering from chronic stress increases the risk of obesity due to changes in certain parts of the brain that lead to food cravings and the desire for sweet foods.

The Australian Institute of Gaban Medical Research has revealed that chronic stress and high-calorie food intake caused by it cause changes in a specific area of ​​the brain (lateral stem), which can lead to obesity, according to mouse experiments.

The brain’s lateral habenula is an area involved in turning off the brain’s reward response switch. This area is activated in the short term so that you don’t overeat when you eat high-calorie, high-fat foods. However, under long-term and chronic stress, this area remains silent, activating reward signals and inducing food to be eaten for pleasure. In other words, they no longer respond to satiety regulatory signals, so they eat comfort food (healing food) relentlessly.

Dr. Kenny Chi Kin Ip, the first author of the study, said, “High-calorie snacks such as sweets can be a good mood changer when you are stressed in the short term, but in the long term, stress can change your brain significantly. This can easily lead to excessive weight gain and obesity.”

Chronic stress disables the brain’s natural response to satiety, which constitutes a reward circuit that constantly calls for cravings. Because of this, most people under stress eat much more than usual and crave foods high in sugar, fat and calories.

The research team investigated how mice responded to food when they were under chronic stress to determine the cause of overeating and high-calorie eating habits. As a result, mice fed a high-fat diet while suffering from chronic stress gained twice as much body weight as mice fed a high-fat diet without chronic stress. It turns out that at the heart of weight gain is a specific molecule (NPY). This molecule is produced naturally by the brain in response to stress.

In addition, mice fed a high-fat diet while suffering from chronic stress drank three times more sweet water (water with sucralose) than mice fed a high-fat diet without chronic stress. Sucralose is a sweetener that is 600 times sweeter than sugar and has no calories. This means that chronic stress creates a particularly strong craving for sweet and savory foods.

The research team blocked certain molecules from activating brain cells in the lateral stem of mice fed a high-fat diet under chronic stress. As a result, they found that the mice ate less recreational food and gained less weight. The results of this study (Critical role of lateral habenula circuits in the control of stress-induced palatable food consumption) were published in the international journal Neuron.