Portion size of food affects energy intake in normal-weight and overweight men and women
Rolls and colleagues served fifty-one men and women lunch once a week for four weeks, varying only the amount of food presented, from a moderate portion to double it. People ate more when given more, and the effect was substantial. The important refinement is the second condition: one group received the food already plated, while the other received it in a serving dish and helped themselves. The result held either way, so it is not explained by politeness or by a reluctance to leave food on a plate. It also held regardless of the participants' weight and characteristics. The authors' conclusion is that portion size is a modifiable cause of how much people eat rather than a reflection of appetite, which makes it a target for intervention. This is the foundational experiment behind portion-size work, and it is independent of the later work on the same theme that this vault treats with caution.
Rolls and colleagues served fifty-one men and women lunch once a week for four weeks, varying only the amount of food presented, from a moderate portion to double it. People ate more when given more, and the effect was substantial. The important refinement is the second condition: one group received the food already plated, while the other received it in a serving dish and helped themselves. The result held either way, so it is not explained by politeness or by a reluctance to leave food on a plate. It also held regardless of the participants' weight and characteristics. The authors' conclusion is that portion size is a modifiable cause of how much people eat rather than a reflection of appetite, which makes it a target for intervention. This is the foundational experiment behind portion-size work, and it is independent of the later work on the same theme that this vault treats with caution.
Written from the abstract, Europe PMC.
What our sources record
Reproduced as it was written when this source was checked, figures and all.
51 adults, four portion sizes across four weekly lunches.
Where we use it
- Why You Are Hungry an Hour After a Big Lunch, Why We Crave
Reliability of this reference
The link below was matched against the publisher's record on title, first author and year, and all three agree.
The source
https://doi.org/10.1093/ajcn/76.6.1207
DOI: 10.1093/ajcn/76.6.1207