The clean plate club: about 92% of self-served food is eaten.

Many eating studies in psychology, consumer behavior and marketing journals are dismissed, because they focus on how much one serves and not how much is eaten. We develop a means of estimating the percentage of self-served food that is consumed under various conditions. An aggregate analysis was conducted of studies where participants served themselves food and where actual intake was measured. Analyses explored what percentage of food was consumed depending on population, food and situational cues and generally showed that adults consistently consume the vast majority (91.7%) of what they serve themselves. This was higher for meals (92.8%) than for snacks (76.1%) and higher when a person was not distracted (97.1%) than when he or she was distracted (88.8%). The percentage eaten did not vary between lab (90.7%) and field settings (91.9%). Because many eating behavior studies outside of nutrition measure food selection, but not intake, the aggregate estimates presented in this research can enable obesity, nutrition and public health researchers to extrapolate how much may have been eaten in such studies. Doing so will extend their relevance to better understanding eating behavior and better developing solutions to overeating.