Obesity Crisis: Being Fat But Fit Does Not Reduce the Risk of Heart Failure and Stroke

Weight loss
An instructor at the Mile High Run Club (MHRC), leads a class in a Manhattan borough of New York, November 14, 2014. Brendan McDermid/Reuters

Being "fat but fit" does not reduce the risk of having a heart failure or stroke, according to a study by British scientists. Researchers looked at the health records of 3.5 million people over 10 years and found obese people who are "metabolically healthy" are still at significantly higher risk of cardiovascular disease than people of a healthy weight.

Over recent years, a number of studies have indicated people can be overweight or obese, but still remain "metabolically healthy", meaning they do not have the conditions that normally go alongside obesity, such as high blood pressure, abnormal blood fats, poor blood sugar control or diabetes. This has led many people to believe it is possible to be obese and healthy—but the latest research suggests this is not necessarily the case.

The scientists looked at people with metabolically healthy obesity (MHO). These are people who are considered clinically obese due to their body mass index (BMI), but who show no signs of obesity-related problems. They compared this group with people who had a BMI in the "normal" range and analyzed the risk of both groups developing four cardiovascular diseases—coronary heart disease, stroke, heart failure and peripheral vascular disease (PVD), where fatty deposits build up in the arteries, restricting blood supply to the legs.

Their findings indicate MHO individuals had a 50 percent increased risk of coronary heart disease, a seven percent increased risk of cerebrovascular disease (which includes stroke) and double the risk of heart failure. When their analysis was adjusted to exclude cigarette smokers, MHO people also had an 11 percent increased risk of PVD.

Study author Rishi Caleyachetty said in a statement: "This is the largest prospective study of the association between metabolically health obesity and cardiovascular disease events. Metabolically healthy obese individuals are at higher risk of coronary heart disease, cerebrovascular disease and heart failure than normal weight metabolically healthy individuals."

He continued: "The priority of health professionals should be to promote and facilitate weight loss among obese persons, regardless of the presence or absence of metabolic abnormalities. At the population-level, so-called metabolically healthy obesity is not a harmless condition and perhaps it is better not to use this term to describe an obese person, regardless of how many metabolic complications they have."