Satiety

Satiety is the sensation of having eaten enough. Nutrition science splits it into satiation — what makes you stop eating during a meal — and satiety proper, which is how long you stay comfortably full afterwards. Both are driven by stomach stretch, by gut hormones including GLP-1, PYY and cholecystokinin, and by leptin signalling from fat tissue.

It matters because for most people the hard part of a calorie deficit is hunger, not arithmetic. Foods that deliver more fullness per calorie make the same deficit substantially easier to hold, which is why protein, fibre and high-volume whole foods do so much practical work in a diet.

In practice this is also the mechanism the GLP-1 medicines act on — they amplify a satiety signal the body already uses. Understanding satiety as a physiological signal rather than a willpower test changes how you design a diet.

Sources

• Reflections on the discovery of GLP-1 as a satiety hormone: implications for obesity therapy and future directions; PMID 38890501