Mom may have been right when she said breakfast is the most important meal of the day. A small study suggests that skipping that morning meal may be a bad move for the heart, and possibly the waistline.

UK researchers found that when healthy, lean women skipped their morning meal, it raised their cholesterol levels and diminished their bodies’ sensitivity to insulin, a hormone that helps regulate blood sugar levels.

On top of that, the women tended to eat more calories on breakfast-free days - suggesting that over the long haul, skipping breakfast could spur weight gain.

Dr. Hamid R. Farshchi and his colleagues at the University of Nottingham in the UK report the findings in the February issue of the American Journal of Clinical Nutrition.

Some past studies have suggested that people who eat breakfast, particularly whole-grain cereals, have lower cholesterol and insulin levels, Farshchi told Reuters Health.

Along with past evidence, he said, the new findings suggest that making time for breakfast is likely to have long-term health benefits.

Whether one of those benefits is a smaller waistline is unclear. Some research, Farshchi noted, has found an association between eating breakfast - again, whole-grain cereals in particular - and lower body weight, but other studies have found no such relationship.

To study the short-term metabolic effects of having and forgoing breakfast, Farshchi’s team had 10 young, normal-weight women spend two weeks on each of two diet plans. Under one plan, the women had bran flakes with low-fat milk for breakfast, then had two meals and two snacks throughout the rest of the day. Under the other, they skipped breakfast, but had the cereal around noon; as in the breakfast plan, they had two additional meals and two snacks during the rest of the day.

Under each plan, the women were allowed to indulge in a mid-morning cookie.

At the end of each two-week period, the researchers measured the women’s metabolic responses to a test milkshake, using blood samples drawn before and after they had the drink.

After the breakfast-free period, the women’s cholesterol levels - including the “bad” cholesterol, LDL - were generally higher, and they showed poorer insulin sensitivity after having the test drink.

Insulin is released after a meal in order to escort digested sugars into body cells to be used as energy. But the body can become resistant to the effects of insulin. Over time, this impaired insulin sensitivity can cause blood sugar levels to soar and possibly lead to type 2 diabetes - which, like high LDL cholesterol, is a major risk factor for heart disease and stroke.

Besides the effects on cholesterol and insulin, skipping breakfast also seemed to make study participants eat more, as the women reported higher calorie intakes on breakfast-free days.

They showed no changes in body weight, but Farshchi said this is not surprising given the short study period. “Further long-term studies are needed to investigate the full impact of breakfast consumption on body weight,” he noted.

What’s interesting about this study, according to Farshchi, is that it points to the importance of eating first thing in the morning. “If the first thing somebody eats in the day is a mid-morning snack and has the cereal later in the day,” Farshchi said, “he or she does not get these metabolic benefits.”

SOURCE: American Journal of Clinical Nutrition, February 2005.