WASHINGTON D.C.: Dismissing the concept of 'fat but fit,’ a recent study has found that carrying those extra kilos could up your risk of heart attack by more than a quarter, even if you are otherwise “healthy.”
The researchers from Imperial College London and the University of Cambridge found that being overweight or obese increased a person's risk of coronary heart disease (CHD) by up to 28 percent compared to those with a healthy body weight, even if they had healthy blood pressure, blood sugar and cholesterol levels.
The findings add to a growing body of evidence that suggests being ‘fat but fit’ is a myth, and that people should aim to maintain a body weight within a healthy range.
The team showed that despite an apparent clean bill of health, this overweight group is still at increased risk compared to those with a healthy weight. In the largest study of its kind to date, scientists used data from more than half a million people in 10 European countries - taken from the European Prospective Investigation into Cancer and Nutrition (EPIC) - to show that excess weight is linked with an increased risk of heart disease, even when people have a healthy metabolic profile.
"Our findings suggest that if a patient is overweight or obese, all efforts should be made to help them get back to a healthy weight, regardless of other factors. Even if their blood pressure, blood sugar and cholesterol appear within the normal range, excess weight is still a risk factor," said lead author Camille Lassale.
Researchers looked at the link between excess weight and risk of CHD, a condition where not enough blood gets through to the heart due to clogged arteries, leading to heart attacks.
After a follow-up period of more than 12 years, a total of 7,637 people in the EPIC cohort experienced CHD events, such as death from heart attack. Body weight was classified according to definitions from the World Health Organization. Those with a body mass index (BMI) over 30 were classed as obese, while those with a BMI of 25-30 were classed as overweight, and 18.5-25 as normal weight. More than half of the control group (63 per cent) were female, with an average age of 53.6 and an average BMI of 26.1.
Participants were categorised as “unhealthy” if they had three or more of a number of metabolic markers, including high blood pressure, blood glucose, or triglyceride levels, low levels of HDL cholesterol, or a waist size of more than 37" (94 cm) for men and 31" (80 cm) for women.
After adjusting for lifestyle factors such as smoking, diet, exercise and socioeconomic status, the researchers found that compared to the healthy normal weight group, those classed as unhealthy had more than double the risk of CHD, whether they were normal weight, overweight or obese.
However, analysis also revealed that within the apparently healthy group there was a significant difference in outcomes for people depending on their weight. The research found that compared to those at normal weight, people who were classified as healthy but were overweight had an increased CHD risk of 1.26 (26 per cent), while those who were healthy but obese had an increased risk of 1.28 (28 per cent).
Researcher Ioanna Tzoulaki noted that the concept of healthy obese didn’t exist. If anything, the study showed that “people with excess weight who might be classed as ‘healthy’ haven't yet developed an unhealthy metabolic profile. That comes later in the timeline, then they have an event, such as a heart attack.”
According to the researchers, the excess weight itself may not be increasing the risk of heart disease directly, but rather indirectly through mechanisms such as increased blood pressure and high glucose.
They added that as no follow up measurements were taken, they cannot show how the group's health status changed over time. However, they add that what is clear from the study is that population-wide prevention and treatment of obesity is needed in order to ensure public health.
The study is published in the European Heart Journal.