Skipping breakfast increases the risk of middle-aged men suffering heart attacks by more than a quarter, a study has found.
The evidence suggests the old adage about breakfast being the most important meal of the day might be right.
Researchers in the US analysed diet and lifestyle data on 26,902 male health professionals aged 45 and over.
Over a period of 16 years, men who regularly skipped breakfast had a 27% greater risk of having a heart attack or dying from heart disease than those who did not.
The same men were more likely to smoke, drink more alcohol, be unmarried and to be less physically active.
However, these factors and others, such as body weight, medical history and overall diet quality, were taken into account by the scientists.
Study leader Dr Leah Cahill, from Harvard School of Public Health in Boston, said: "Skipping breakfast may lead to one or more risk factors, including obesity, high blood pressure, high cholesterol and diabetes, which may in turn lead to a heart attack over time.
"Don't skip breakfast. Eating breakfast is associated with a decreased risk of heart attacks.
"Incorporating many types of healthy foods into your breakfast is an easy way to ensure your meal provides adequate energy and a healthy balance of nutrients, such as protein, carbohydrates, vitamins and minerals.
"For example, adding nuts and chopped fruit to a bowl of whole grain cereal or steel-cut oatmeal in the morning is a great way to start the day."
Eating last thing at night was also shown to be an unhealthy habit.
Men who reported eating after going to bed had a 55% higher risk of heart disease, although not many fell into this category.
During the study, a total of 1,572 men experienced a first-time cardiac event, such as a heart attack. The findings are reported today in the American Heart Disease journal Circulation.
Men who did eat breakfast ate on average one more time per day than those who skipped the meal.
This implied that those who ignored breakfast were not making up for the loss by eating more later in the day.
Victoria Taylor, senior dietician at the British Heart Foundation, said: "In the morning rush it can be all too easy to skip breakfast, but this study suggests this could have a bigger impact on our health than we might think.
"However, these researchers only looked at men over 45 so we would need to see further research to confirm that breakfast has the same impact on the heart health of other groups of people.
"What we do know is that a healthy and filling breakfast can make that mid-morning biscuit less tempting, as well as giving you another opportunity to widen the variety of foods in your diet."