Bottomless bowls of soup; a self-filling popcorn bucket; big plates versus small ones; and tall versus short glassware. These are all devices behavioral scientists have used to study human consumption habits in an effort to find out what prompts us to overconsume.
A new systematic review of 58 studies capturing data from 6,603 participants has produced convincing evidence that people consume more food when they are offered larger-sized portions or when they use larger items of tableware. The research, carried out by the University of Cambridge and published in the Cochrane Library, suggests that completely eliminating larger-sized portions from the diet could reduce energy intake by up to 16% among U.K. adults or up to 29% among U.S. adults.
As part of the review, researchers at the Cambridge Behaviour and Health Research Unit investigated the influence of portion, package and tableware size on food consumption. The data showed that people consistently consume more food when offered larger-sized portions, packages or tableware than when offered smaller-sized versions. If sustained reductions in exposure to large sizes could be achieved across the whole diet, the researchers suggested, average daily energy consumed from food could drop by 12%–16% among adults in the U.K. (up to 279 kilocalories per day) or by 22%–29% among U.S. adults (up to 527 kcal per day).
The researchers did not find that the size of this effect varied greatly between men and women, or by BMI, susceptibility to hunger, or tendency to consciously control one’s eating behavior.