Middle-age people who are overweight but have normal blood pressure and cholesterol levels are kidding themselves if they think their health is just fine, medical researchers say.
Northwestern University researchers tracked 17,643 patients for three decades and found that being overweight in midlife substantially increased the risk of dying of heart disease -- even in people with healthy blood pressure and cholesterol levels.
High blood pressure and cholesterol are strong risk factors for heart disease. Both are common in people who are too fat, and often are thought to explain why overweight people are more prone to heart disease.
But there is a growing body of science suggesting that excess weight is an independent risk factor for heart attacks, strokes and diabetes.
The new study fits with that evolving school of thought and contrasts with a controversial government study published last year that suggested excess weight might not be as deadly as previously thought.
"The take-home message would be pay more attention to your weight even if you don't have an unhealthy risk factor profile yet," said lead author Lijing Yan, a researcher at Northwestern and Peking University.
The study appears in today's Journal of the American Medical Assn.