The research: The ‘key’ to long-term diet success has been found

Many people who have dieted from time to time are well aware of the “yo-yo effect” or “weight rebound”, and usually quickly regain the weight after the diet is over.

A change in the communication of neurons

Researchers from the Max Planck Institute for the Study of Metabolism and Harvard Medical School believe they have found the reason why millions of people around the world have lost the “battle” with scales in the long run. As they saw through experiments on mice, the connectivity of neurons in the brain changes during the diet. In particular, the neurons that regulate the feeling of hunger receive stronger signals, causing the experimental animals to consume a lot of food after the diet ends and quickly regain weight.

for drug development

According to the researchers, these findings, published in the journal Cell Metabolism, could lead to the development of drugs that block the transmission of powerful hunger signals and ultimately help maintain low weight after a diet.

“So far, most of the focus has been on the short-term effects of dieting. We wanted to see what changes in the brain are in the long term after the diet,” explained study leader Henning Wencelau from the Max Planck Institute for the Study of Metabolism.

AgRP “key” neurons

Dr. Wencelao and his colleagues put mice on a diet and observed which brain circuits showed changes due to reduced food intake. They focused in particular on a group of neurons in the hypothalamus called AgRP neurons, which are known to control hunger.
The researchers showed that the neural pathways that excite AgRP neurons send enhanced signals when the animals are on a diet. This significant brain change can even be detected long after the diet has ended.

Prevent weight gain

The scientists were also able to selectively suppress in mice the neural pathways that activate AgRP neurons. This resulted in less weight regain after the diet.

“The new findings may provide us with an opportunity to reduce the yo-yo effect,” noted Dr. Fenselau and concluded: “Our long-term goal is to find treatments for people to help maintain weight loss after dieting. To achieve this, we will continue to explore how we can block the mechanisms that control amplification. The neural signals of hunger are in humans, too.”