Feb. 16 (HealthDay News) -- When children snack together in large groups, they tend to eat about a third more than when they snack with just a couple of friends, a new study finds.

Researchers at the University of Michigan examined the eating habits of 54 children, aged 2-and-a-half to 6-and-a-half, when they were placed in groups of nine children and in groups of three. Each child was given the same-sized snack. The researchers recorded how much each child ate on each occasion and how long it took them to eat.

Children in the larger groups ate 30 percent more than the children in the smaller groups. The time they took to eat was not a factor.

Children in the larger groups started to eat sooner and more quickly, and also spent less time socializing than children in the smaller groups.

This behavior of eating more when in larger groups than when alone is common among adults and is also seen in many other animals. This "social facilitation" is the result of stimuli provided by the sight and sounds of others engaged in similar behavior, which overrides the brain's normal signals that enough food has been consumed, the researchers explained.

They said their findings suggest that children who don't eat enough might benefit from having meals with family and/or friends at home. Children who already eat too much should not eat in fast-food restaurants, where the hectic surroundings may stimulate them to overeat.