Protein is often a crucial component of weight-loss plans because of its ability to provide satiety over the course of several hours. A study published in the July 2012 issue of Cell provides further insight into how the body digests proteins and how they trigger greater levels of appetite suppression than either carbohydrates or fat. A team of researchers from Inserm, CNRS and the Université Clause Bernard Lyon 1 has pinpointed the mechanisms that create the sensations of fullness in the hours following a protein-rich meal, potentially paving the way for the medical community to improve the lives of their overweight or obese patients. Essentially, dietary proteins trigger a two-part chain reaction within the nervous system that generates an appetite-suppressing message in the intestine. Specific receptors in the portal vein nervous system, located at the outlet of the intestine, are inhibited by oligo-peptides produced during protein digestion. The receptors send a message to the brain, which then sends a return message triggering glucose synthesis in the intestinal mucosa. The intestine sends the message via neuropeptides “to suppress appetite” back to the parts of the brain that control food intake. Previous studies had already shown that the consumption of dietary protein triggers glucose synthesis in the intestine, resulting in the appetite-suppressing signal that is sent to the brain, generating the feeling of fullness. The challenge now is to determine how to act on the receptors that control the sensation of fullness without inadvertently making them insensitive. According to lead author Gilles Mithieux, “A means of activating them 'moderately' must be found, thus retaining their long-term beneficial effects on controlling food intake.” (Cell, 2012)