Does intraduodenal fat infusion increase satiety and reduce food intake via cholecystokinin in young adults?

What we’ve found so far suggests that fat in the small intestine can signal fullness through this hormone pathway in healthy young adults. The mechanism appears consistent: fat triggers cholecystokinin, which then reduces how much people eat. There were no studies in our review that contradicted this pattern.

This does not mean fat always reduces hunger in every situation — the effect was observed under controlled conditions using direct infusion, not through normal eating. We also don’t know if this works the same way in older adults, people with metabolic conditions, or with different fat amounts. The evidence we’ve reviewed is limited to one specific setup and one group of people.

For now, the pattern points to cholecystokinin playing a role in how the gut responds to fat, and that response may help reduce eating. But this is just one piece of a much larger picture.

In everyday terms: if fat reaches your small intestine, your body may naturally signal you to stop eating — but this doesn’t mean eating more fat will make you less hungry in real life. The way fat is delivered matters.