Breakfast, we are told, is the most important meal of the day. Now neuroscientists are starting to understand why. Skipping the first meal of the day not only means you eat more at lunch, research has found, but also that your brain will be primed to seek out higher calorie, unhealthy food.

Dieters who skip meals also often end up gaining weight long term.

Hungry ... if you skip breakfast, you are more likely to eat unhealthy food later in the day, a study says.. Credit:Michel O'Sullivan

Tony Goldstone, of the MRC Clinical Science Centre at Imperial College London, found that prolonged fasting seemed to prime certain brain regions to move to higher calorie foods when a meal was finally found. "That makes evolutionary sense if you're in a negative energy-balance situation," the consultant endocrinologist said. "You're not going to waste your time going for lettuce."

He will present his study on Wednesday at the Society for Neuroscience in New Orleans.

Goldstone scanned the brains of 21 men and women, all near the age of 25, on two days as they looked at pictures of food and rated how appealing they found items ranging from chocolate to vegetables. On one day the volunteers had no breakfast before the scans; on the other they had a 750-calorie breakfast. After the scans the volunteers had lunch. "Not surprisingly, when they are fasted they are hungry and they rate the high-calorie foods as more appealing." When volunteers skipped breakfast they ate about 20 per cent more lunch.

Their scans also showed that orbitofrontal cortex activity was especially responsive to high-calorie foods. Brain-scan studies by Goldstone's team on gastric surgery patients found orbitofrontal cortex activity was less in those who had had bypass surgery compared with those who had a gastric band. "We think people do better after bypass [because] you alter the craving for high-calorie foods, which is mediated by the orbitofrontal cortex."

Guardian News & Media