Topline

Leading an active lifestyle is not enough to counter the negative effects of being overweight on heart health, according to new research published today, challenging the idea that fitness is more important than weight in leading a healthy lifestyle, and prompting calls for policymakers to rethink health initiatives that prioritize physical activity over weight loss. 

Key Facts

Researchers analyzed data from over 500,000 adults and grouped people based on activity levels and body weight, evaluating their heart health by assessing three major risk factors for stroke and heart attack: diabetes, high blood pressure and high cholesterol.   

Overweight and obese participants in the study were more likely to have high cholesterol, diabetes and high blood pressure compared to their normal-weight peers of any activity level, the researchers wrote in the European Journal of Preventative Cardiology, a finding that held when men and women were analyzed separately.

While being active was linked with better heart health for anyone, study author Dr. Alejandro Lucia, from the European University in Madrid, said the results indicate that “exercise does not seem to compensate for the negative effects of excess weight,” contradicting the popular notion that one can be “fat but healthy.”

Lucia said this notion “has led to controversial proposals for health policies to prioritize physical activity and fitness above weight loss,” policies he believes should be reconsidered to make “weight loss… a primary target” for reducing the risk of cardiovascular disease in overweight and obese people. 

Key Background

While a substantial amount of research shows that being active is protective against any number of ailments, the impact of bodyweight has proven more controversial. Many, as Lucia noted, support the idea that one can be “fat but fit” and there is evidence that suggests fitness can help compensate for being overweight. This paper is unlikely to settle that controversy and has a number of methodological flaws that would need to be addressed to settle the matter conclusively. Professor Keith Frayn, an emeritus professor of human metabolism at the University of Oxford, said it “should be considered only a starting point” when talking about the relationship between fitness, weight and health. Frayn said the study’s design means it could have missed health factors that are “not necessarily reflected in the blood measurements reported here” as well as benefits that go “beyond protection against cardiovascular (and) metabolic disease.” 

Chief Critic

Michael Pencina, vice dean for data science and information technology at Duke University School of Medicine, told CNN that the study cannot lead one to a conclusion on the cause of ill health. “This is a cross sectional study,” he said. “All we can talk about is associations.” The study cannot, for example, tell us whether a person became active because they were obese or were active and still became obese, Pencina explained. 

Crucial Quote

Professor Metin Avkiran, Associate Medical Director at the British Heart Foundation, said the “study adds to existing evidence that there is no such thing as ‘healthy obesity’” as well as providing “confirmation that being physically active protects against these risk factors.” 

Further Reading

Joint association of physical activity and body mass index with cardiovascular risk: a nationwide population-based cross-sectional study (European Journal of Preventative Cardiology)

‘Fat but fit’ is a myth when it comes to heart health, new study shows (CNN)

‘Fat but Fit’? The Controversy Continues (NYT)

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