‘Fat but fit’? The controversy continues

Can you be fit and healthy, even if you’re overweight? And will working out, despite the extra pounds, reduce your risk of a heart attack?

The idea that you can be “fat but fit” has long been controversial. While health experts endorse physical activity as beneficial, many doctors view the concept of being “fat but fit” with suspicion. Now a new study, believed to be the largest of its kind, suggests that even when overweight or obese people are free of health complications, they are still more likely to develop heart disease than their peers who aren’t overweight.

It didn’t matter whether obese people were free from diabetes, high blood pressure or high cholesterol, a condition sometimes referred to as “metabolically healthy obesity.” As long as they were obese, they were at modestly higher risk for having a stroke, at nearly 50 percent greater risk of coronary heart disease and had nearly double the risk of developing heart failure than people who were not overweight and in similar metabolic health.

People who were metabolically healthy but considered merely overweight were at a 30 percent greater risk of coronary heart disease compared to their normal weight and metabolically healthy peers. “The bottom line is that metabolically healthy obesity doesn’t exist,” said Rishi Caleyachetty, of the College of Medical and Dental Sciences at the University of Birmingham in England, who was the lead author of the paper, published in the Journal of the American College of Cardiology. “Obesity is not a benign condition.”

But critics say the analysis, based on the electronic health records of 3.5 million British patients who were followed from 1995 to 2015, leaves a lot out. Doctors’ records don’t typically capture lifestyle habits, so the study fails to account for the wide-ranging effects of diet. They classify weight status by using body mass index, a formula based on height and weight that doesn’t distinguish muscle from fat. Most important, critics say, such analyses don’t take fitness level or physical activity into account.

Other studies have found a higher rate of heart failure among obese individuals, said Carl Lavie, the medical director of cardiac rehabilitation and preventive cardiology at the John Ochsner Heart and Vascular Institute in New Orleans. But when it comes to coronary heart disease outcomes, studies that take both weight and physical fitness into account have concluded that “fitness is more important than fatness,” at least for the moderately obese, he said.