According to new research, the negative effects of excess body fat on heart health can't be canceled out by maintaining an active lifestyle.
Previous studies had suggested that being physically fit could mitigate the negative effects of being overweight on heart health; the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC), published a study on Thursday that said it is not the case, reports the CNN.
"One cannot be 'fat but healthy.' This was the first nationwide analysis to show that being regularly active is not likely to eliminate the detrimental health effects of excess body fat," said study author Alejandro Lucia, a professor of exercise physiology at the European University of Madrid.
"Our findings refute the notion that a physically active lifestyle can completely negate the deleterious effects of overweight and obesity."
Previous research provided some evidence that people who were "fat but fit" could have similar cardiovascular health to those who were "thin but unfit," but Lucia said this has had unintended consequences.
"This has led to controversial proposals for health policies to prioritise physical activity and fitness above weight loss," he said. "Our study sought to clarify the links between activity, body weight, and heart health."
Researchers used data from 527,662 working adults from Spain insured by an occupational risk prevention company, with an average age of 42.
They were put into groups according to activity level and groups by body weight: 42% of participants were normal weight, with a body mass index (BMI) of 20-24.9; 41% were overweight, BMI 25-29.9; and 18% were obese, BMI 30 or above.
Then researchers looked at their cardiovascular health by categorising them for diabetes, high cholesterol and high blood pressure, all of which are major risk factors for stroke and heart attack.
After investigating the associations between BMI, activity level and risk factors, researchers concluded that any level of activity meant it was less likely that an individual would have any of the three risk factors compared with no exercise, with the risk of high blood pressure and diabetes decreasing with increased activity levels.
"This tells us that everyone, irrespective of their body weight, should be physically active to safeguard their health," Lucia said.
However, the study showed greater cardiovascular risk for overweight and obese participants compared with those of a normal weight, regardless of how much exercise they did.
Participants who were obese and active were twice as likely to have high cholesterol, four times as likely to have diabetes and five times as likely to have high blood pressure as those who were normal weight but inactive.
"Exercise does not seem to compensate for the negative effects of excess weight," Lucia said. "This finding was also observed overall in both men and women when they were analysed separately."
Lucia underlined that it is "equally important" to fight obesity and inactivity.
"Weight loss should remain a primary target for health policies together with promoting active lifestyles," he said.