Background: The influence of parents versus friends on youths' eating behavior has not been directly compared, and little is known about the developmental effects of social influences on their eating behavior.
Objective: The objective was to compare the effects of mothers and friends on children's and adolescents' energy intake from sandwiches and from healthy and unhealthy snacks and dessert foods.
Design: Twenty-three children (ages 5-7 y) and 27 adolescents (ages 13-15 y) ate a meal with their mother on one occasion and with a same-sex friend on another occasion.
Results: Male and female children consumed less energy from unhealthy snacks when in the presence of their mothers than when in the company of their friends. Conversely, female adolescents consumed less energy from unhealthy snacks and more energy from healthy snacks when they were with their friends than when with their mothers.
Conclusions: Food selection is differentially influenced by the source of social influence and the age and sex of the child. Parents may act as an inhibitory influence on unhealthy eating for younger children. Adolescent girls may try to convey a good impression of healthy eating when eating with same-sex friends, but the eating habits of teenage boys are not as influenced by the social context. This trial is registered at clinicaltrials.gov as NCT00875576.