Which Is Worse: Being Unfit or Being Fat?

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Carrying around too much weight and not exercising are two surefire ways to shorten your life. Which one's worse? A new study reveals that lack of physical activity causes twice as many early deaths as having too much flab.

Researchers at the University of Cambridge in the UK compared the body-mass indexes, waist circumferences, physical activity levels, and other heath data of more than 330,000 men and women over 12 years. They observed the greatest reduction in mortality risk between inactive people and those who were moderately active. This told them that being sedentary carries double the death risk as having a BMI of 30 or higher. The researchers also discovered that, regardless of BMI or other mortality risk factors such as smoking and drinking, inactive people were up to 30 percent more likely to die early than those who were even just moderately inactive (less than 3.5 hours of physical activity per week). So a brisk 20-minute daily walk is all it takes to be considered moderately inactive, thereby slashing your death risk by 30 percent, they say.

"Physical activity has numerous positive effects on blood pressure, glucose metabolism, insulin sensitivity, blood lipids, and so on, regardless of being overweight," says lead study author Ulf Ekelund. In other words, getting off your butt is the more effective way to get all of those health markers in check, which can in turn help you to live longer.

Men especially should take heed, Ekelund adds. "Men tend to die at an earlier age than women and usually have larger waistlines," he says. "Thus, regular physical activity — and the more of it the better — is one of the best medical treatments you can get, without any side effects."