Skipping the breakfast regularly raises men's chances of developing diabetes by more than 20 percent, scientists warn.
It follows previous research suggesting that breakfast is crucial to maintaining good health.
The latest results, from a major investigation involving 30,000 men, provide the strongest evidence yet that it can reduce the risk of diabetes.
They show that even men who are not overweight and may have a reasonably healthy diet the rest of the time could still be at risk if they miss breakfast.
The findings emerged as part of a wide-ranging study being carried out into male health by researchers at Harvard School of Public Medicine in the United States.
They tracked the breakfast habits of 29,206 men over a 16-year period. None had diabetes at the start of the study.
The study - published in the American Journal of Clinical Nutrition - found that those who hardly ever had breakfast had a 21 per cent increase in risk compared with those who did.
And men who ate properly only once or twice a day were 25 per cent more likely to get the condition than those eating three meals.
"Having three main meals a day, including breakfast, seems to be the optimal eating pattern for a decreased risk of type 2 diabetes," the Harvard team said.
They added that research is needed to see if women are affected in the same way.
Breakfast has been shown to reduce levels of low-density lipoprotein, the 'bad' cholesterol responsible for clogging up arteries around the heart.
People who do not eat first thing are also more likely to snack on sugary foods and less likely to exercise.
Dr Iain Frame, director of research at Diabetes UK, said the type of breakfast is also important.
"While it is intuitive that eating three healthy balanced meals a day is good for your health, in this study it is not clear what is meant by breakfast or what it consists of," he stated.
"As we know, there are various options - healthy and unhealthy - of what could be considered breakfast.
"We recommend a healthy balanced diet, rich in fruit and vegetables and low in sugar, salt and fat, which applies to breakfast and all other main meals," Dr Frame added.