Before we answer this question, we'd like to distinguish between satiety and satiation as many people do not know the difference.
Satiation is meal termination which is a temporary sensation of fullness experienced by a person which causes them to stop eating a meal. Satiety, on the other hand, is the long-term sensation of fullness that usually prolongs the initiation of the next meal.
Many individuals in the nutrition industry attribute satiety to the role of several key hormones such as CCK, GLP-1, and PYY in the body. However, the relevance of these hormones in the context of energy intake is questionable.
This is in part due to a meta-analysis and review of studies that used the infusion of these hormones into the body and compared them to the amount produced within the body. It was noted that the amount of GLP-1 and PYY, individually, required to reduce energy intake was multitudes higher than what is produced within our body thereby questioning the reliability of using these hormones as markers of energy intake in the first place. In this meta-analysis, CCK was shown as a reliable predictor but we'd still like to know more on this topic before can say it would have a significant impact on energy intake.
Conclusively, sensations of satiety may not reliably predict energy intake. This notion is surprising but indicates that mechanistic evidence doesn't always play a substantial role in humans.
