Previous studies have suggested that being physically fit can mitigate the negative effects of being overweight on heart health, but this is not the case, according to a new study in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC ), published Thursday.
“You can’t be ‘fat, but healthy’. This was the first national analysis to show that being regularly active probably does not eliminate the damaging health effects of excess body fat, “said the study’s author, Alejandro Lucia, professor of exercise physiology at the European University in Madrid.
“Our findings refute the notion that a physically active lifestyle can completely negate the deleterious effects of overweight and obesity.”
Previous research has provided some evidence that people who were “fat but fit” could have cardiovascular health similar to those who were “thin but inadequate”, but Lúcia said that this had unintended consequences.
“This has led to controversial health policy proposals to prioritize physical activity and fitness over weight loss,” he said. “Our study sought to clarify the links between activity, body weight and heart health.”
The researchers used data from 527,662 adult workers in Spain, insured by an occupational risk prevention company, with an average age of 42 years.
They were placed in groups according to the level of activity and groups according to body weight: 42% of the participants were of 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 more.
Next, the researchers analyzed their cardiovascular health, categorizing them in relation to diabetes, high cholesterol and high blood pressure, which are important risk factors for stroke and heart attack.
After investigating the associations between BMI, activity level and risk factors, the researchers concluded that any level of activity meant that an individual was less likely to have any of the three risk factors compared to no exercise, with the risk of hypertension and diabetes decreasing with increasing activity levels.
“This tells us that everyone, regardless of their body weight, must be physically active to protect their health,” said Lúcia.
However, the study showed a higher cardiovascular risk for overweight and obese participants compared to those with 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 more likely to have high blood pressure than those who were normal weight but inactive.
“Exercise does not seem to compensate for the negative effects of being overweight,” said Lúcia. “This finding was also observed in general in both men and women, when analyzed separately.”
Lúcia stressed that it is “equally important” to fight obesity and a sedentary lifestyle.
“Weight loss should continue to be the primary goal of health policies, along with promoting active lifestyles,” he said.
‘We don’t know which came first’
The doubts remain, however, around the circumstances of those involved in the study.
“This is a cross-sectional study – all we can talk about is associations, we can’t talk about causality,” Michael Pencina, vice president of data science and information technology at Duke University School of Medicine, told CNN.
“As a cross-sectional study, we don’t know which came first – what this study is not telling us is, the person who is obese and active, did he become active when he realized he was obese and the risk factors were high? Or were active and, despite this, became obese and their risk factors increased? “Pencina, who was not involved in the study, he added.
“What we see is that the burden of risk factors increases according to the weight category. Obese people have the highest burden of associated risk factors. This remains true according to the level of activity, ”he added.
The study adds to an extensive body of research on the subject.
“While the controversy over the precise contribution of weight to exercise to cardiovascular health is likely to continue, to optimize health and minimize the risk of cardiovascular disease, patients should pay attention to both: maintain a healthy weight and be physically active, “said Dr. Anthony Rosenzweig, head of the cardiology division at Massachusetts General Hospital in Boston and professor of medicine at Harvard Medical School.