Does breakfast make you fat?

For years nutritionists have been telling us to make sure we start the day with a substantial healthy breakfast. "Breakfast like a king" is the often repeated mantra. But research by French scientists published in this month's British Journal of Nutrition has found that the advice may be misplaced. They say a humble piece of buttered toast is a much healthier petit déjeuner than bread, yoghurt and fruit, as the latter is likely to lead to weight gain.

For years nutritionists have been telling us to make sure we start the day with a substantial healthy breakfast. "Breakfast like a king" is the often repeated mantra. But research by French scientists published in this month's British Journal of Nutrition has found that the advice may be misplaced. They say a humble piece of buttered toast is a much healthier petit déjeuner than bread, yoghurt and fruit, as the latter is likely to lead to weight gain.

Scientists at the Human Nutrition Research Centre in Lyon monitored 10 healthy men aged 28 who spent two weeks eating a low-calorie breakfast, and two weeks eating a high-calorie breakfast. The former consisted of a slice of buttered toast and sugared tea or coffee, which came to about 100 calories, representing about 5 per cent of the participants' daily calorie intake. For the latter, participants ate 100gms of buttered bread and jam, sugared yoghurt, a piece of fruit and sugared tea or coffee, which came to about 700 calories. They ate as normal for the rest of the day, and the average daily energy intakes were similar. There was a four-week break between changing breakfasts.

Ambroise Martin, professor of nutrition and biochemistry at Lyon Medical School, one of the scientists who conducted the study, said that after eating the high-energy breakfast, participants' ability to burn fat was reduced. "The amount of ingested fat was about the same as in the low-energy period, but there was a difference in fat oxidation... In the long term, it could induce weight-gain." He added that the reduction in the body's ability to burn fat was caused by its preference to metabolise carbohydrates.

"In many countries there is a general recommendation for a high-energy breakfast, which represents about 25 per cent of daily calorie intake," said Prof Ambroise. "When we began this work we tried to find in scientific literature the scientific basis of this recommendation, but we did not succeed. It appears that it originates from observational studies, but there was no sound science behind it.

"We recommend that people continue having breakfast, it's very important. But if you usually consume a breakfast which represents 15 to 20 per cent of your daily calorie intake, it's not necessary to increase it. We recommend people continue with their traditional breakfast." He added that it was also important to consume evenly portioned amounts of fat and carbohydrates throughout the day.

Claire MacEvilly, a nutrition scientist at the British Nutrition Foundation, said: "The study is really good, you probably couldn't get a better design. But as the paper says, it is very much a preliminary study. It was only for two weeks, and there were only 10 people."

However, she agreed that there was no reason to consume 25 per cent of one's daily calorie intake at breakfast time. "We would suggest that people think about what they are eating at breakfast, where they are getting their energy from, and that they should look at cutting down the fat."

A healthy breakfast, she said, would consist of a bowl of cereal with low-fat milk and a glass of orange juice. A typical fried English breakfast of bacon, sausage and fried eggs would provide the same amount of calories as the French high-calorie breakfast. "If you are going to do it, grill everything to bring down the overall fat intake. But it's not something we would recommend every day."