According to a new study, being “fat but fit” is still far from reality. In fact, those who are overweight or obese risk up to 28 percent increase in risk for coronary heart disease (CHD).
In recent years, the term “fat but fit” has been adopted by the general public to describe those who seem “metabolically healthy” despite carrying some extra weight. In the clinical sense, being metabolically unhealthy refers to having at least three of the following conditions at baseline:
But studies have found evidence to the contrary. And the current study, led by researchers from the Imperial College London (ICL), adds confirmation that “fat but fit” may just be a myth.
The study followed 17,640 people over 12 years – the largest study to date to answer this question. During this time, the researchers recorded body mass index (BMI) data, along with development of heart disease. BMIs measure body fat factoring in height and weight, with normal BMI ranging between 18.5–24.9. BMIs between 25–29.9 are considered overweight, and over 30 is considered obese.
The team found that high BMI was a risk factor for heart disease, irrespective of the person’s metabolic health. Those who met the definition of “fat but fit” had a 28 percent increase in heart disease risk, as compared to those with lower BMIs.
On the flipside, having a normal BMI is not enough to protect against heart disease either. That is, those who had a normal weight but were metabolically unhealthy were also more likely to develop heart disease. In fact, these people had a higher risk of heart disease than those who were considered “fat but fit.”
“Irrespective of BMI, metabolically unhealthy individuals had higher CHD [coronary heart disease] risk than their healthy counterparts. Conversely, irrespective of metabolic health, overweight and obese people had higher CHD risk than lean people,” the authors concluded.
To put it bluntly, “there is no such thing as being healthy obese,” per Camille Lassale, an epidemiologist at ICL who led the study. "Even if you are classified as metabolically healthy, (excess weight) was associated with an increased risk of heart disease. It's another brick in the wall of evidence that being healthy overweight is not true."
The study suggests that those who carry extra weight and are metabolically fine now may be biding their time before health problems surface. Lassale hopes these results, among other similar studies, will reinforce the dangers of obesity. "The take-home message here is that maintaining a healthy body weight is a key step towards maintaining a healthy heart,” said professor Metin Avkiran, an associate medical director at the British Heart Foundation, who was not involved in the study.