The findings by Dr Anthony Leeds confirm teachers' long-held suspicions that children who are hungry perform less well academically. Staffroom anecdotes also suggest that pupils are unmanageable after eating lunches with high contents of fat and additives.
Dr Leeds' preliminary findings are based on a questionnaire answered by pupils in primary and secondary schools in Hertfordshire and Devon. He hopes to conduct a full study of 10,000 children later this year.
Some nutritionists have suggested that glucose levels regulate brain functions, including memory and learning. They say children's ability to recall and use new information, verbal fluency and attention span can be affected if they have eaten nothing since the night before and their glucose levels are low.
Academics in Denmark have shown in a controlled study that children who eat a good breakfast make fewer mistakes in addition tests. They have also found that those who have eaten find it easier to remember things quickly and accurately.
Dr Leeds stressed that his findings were preliminary and that more work was needed before they could be confirmed, but added that schools should consider offering breakfast to pupils. Increased parental choice might have led to pupils travelling to schools further from home, he said, and some might arrive hungry even if they had eaten before they left.
"There is evidence that whether or not children have had breakfast does affect things like concentration and to some extent behaviour," he said.
Nutritionists recommend that children should always have something to eat before leaving home in the morning, such as cereal, fruit, fruit juice or wholemeal toast. Some schools in Britain already offer breakfast to pupils, and in the United States one-fifth of children eat breakfast at school each day.Reuse content