Science of human weight regulation

Ready for some simple physiology and biochemistry?

The hypothalamus is a portion of your brain that helps regulates human weight. It is turned on to continuously feed, signaling to increase hunger and decrease satiety. In order to offset this evolutionary mechanism, the gastrointestinal tract sends satiety hormones to the brain to signal it stop eating when food is in the intestines and fat cells send hormones to the brain to tell the brain to stop continuous feeding.

There are many hormones involved, but GLP-1(glucagon like peptide-1) has recently come into the spotlight for its significant weight regulation potential. GLP-1 is naturally secreted upon the ingestion of food. It signals to the pancreas to enhance glucose-dependent insulin secretion and decrease postprandial glucagon secretion, it signals to the liver to reduce hepatic glucose output, it signals to the stomach to slow gastric emptying and it signals to the brain to promote satiety and reduce hunger.

Medications like semaglutide and tirzepatide, which are classified as glucagon-like peptide-1 receptor agonists, when used in conjunction with diet and exercise, can cause significant weight loss and a reduced risk of cancer, diabetes and heart disease in people who are obese or overweight.