After eating, even when we feel full, many of us still have a desire for more food. This time, the craving is specifically for sweets. What is the reason behind this, and how does the brain respond?
Researchers explain that the body’s desire for sweets after being completely satisfied is “logical” because sugar provides quick energy. After finishing a meal, neurons in the brain send signals to the body indicating fullness. Despite this feeling of fullness, many are puzzled by the persistent urge for sweets.
Unraveling the “Sweet Tooth”:
Recent studies conducted by scientists at the Max Planck Institute for Metabolism Research have shed light on this phenomenon, often referred to as “sweet tooth.” This need is rooted in the brain, where the neurons responsible for signaling satiety are the same ones that trigger cravings for sweets afterward.
In experiments with laboratory rats, researchers found that the sweet tooth urge occurs due to the release of beta-endorphins in the body. Endorphins are chemicals produced by the body that have effects similar to morphine, alleviating pain and inducing feelings of happiness or euphoria.
The researchers emphasize that the craving for sweets after feeling full is logical, as sugar provides rapid energy. When the rats consumed sugar after feeling full, a group of neurons in the brain called POMC released beta-endorphin, which stimulates a reward sensation. This pathway is specifically activated by sugar, not by ordinary or fatty foods.
Interestingly, when the researchers blocked this neural pathway in the brain, the rats refrained from consuming additional sugar. This occurred only with the rats that felt full, not with those that were hungry.
The study didn’t just focus on rats; researchers also conducted brain scans on a group of volunteers who received a sugary solution through their bloodstream. They found that the same area of the brain in humans reacts to sugar in a manner similar to that observed in rats.
Henning Vinslaw, the head of the research group at the Max Planck Institute and supervisor of the study, states: “Sugar is rare in nature, but it provides energy quickly. The brain is programmed to control sugar intake whenever it is available.”
Researchers hope that this study will aid in developing more effective treatments for obesity. Vinslaw notes, “There are already medications that block opioid receptors in the brain. However, weight loss occurs less frequently with appetite suppressant injections. We believe that combining these with other treatments could be highly beneficial. Nonetheless, we need to conduct further investigations on this matter.”
