Researchers have discovered yet another reason why children who already eat too much should be kept out of fast food restaurants.

They have found that children who snack while in big groups eat significantly more than those who eat with just a few people.

The researchers analysed the eating behaviour of 54 children aged between two-and-a-half and six-and-a-half. They were monitored while they ate in groups of three and groups of nine.

Each child was given a standard snack and the amount consumed was weighed on each occasion. The time taken to eat it was also assessed.

The study found that children ate slightly more in the larger groups if the snacking time was less than 11 minutes.

However when the snacking time went on for longer, those in the larger groups ate 30% more than those in the smaller groups, irrespective of the time they took to actually eat their snacks.

According to the researchers, the pattern of eating more in larger groups is already common among adults and animals. This phenomenon is known as ‘social facilitation’ and it stems from the stimuli provided by the sight and sound of others engaged in the same behaviour. It overrides the brain’s normal signs of satiety (feeling full).

Children eating more when in larger groups can be partially explained by the fact that they tend to start eating sooner and more quickly in these circumstances, the researchers said.

“Children who eat too little might fare better eating with family and/or friends at home. And children who already eat too much should keep away from fast food restaurants, where the busy and chaotic environment might stimulate them further to eat even more”, they added.