Being ‘fat but fit’ really is impossible: Doctor says term is ‘misleading, should be avoided’

GLASGOW, Scotland — The idea that people can be “fat but fit” is one that’s been long debated among health experts. But according to a new study, the ability to be in good shape and obese really is just wishful thinking.

Researchers at the University of Glasgow say obese people with a healthy metabolic profile are still four times as likely to develop Type 2 diabetes. They also face twice the risk of suffering heart failure and over a quarter more prone to respiratory disease. And the bad news doesn’t stop there: study results show that “fat but fit” adults are around a fifth more vulnerable to heart attacks, strokes and COPD (chronic obstructive pulmonary disease).

This is despite having normal blood pressure, blood sugar and cholesterol levels.

“People with metabolically healthy obesity are not ‘healthy,” says study leader Dr. Frederick Ho, of the Institute of Health and Wellbeing at the university, in a statement. “They are at higher risk of heart attack and stroke, heart failure, and respiratory diseases compared with people without obesity who have a normal metabolic profile.

Ho says this segment of the population are more susceptible to potentially fatal conditions than peers with high blood pressure, glucose or blood fats — who are not overweight.

“Weight management could be beneficial to all people with obesity irrespective of their metabolic profile,” he adds. “The term ‘metabolically healthy obesity‘ should be avoided in clinical medicine as it is misleading, and different strategies for defining risk should be explored.”

‘Fat but fit’ individuals face much higher risk of potentially deadly health problems

The findings, published in the journal Diabetologia, are based on 381,363 people in the UK Biobank project. Participants were tracked for an average of over 11 years.

“People with metabolically healthy obesity were at a substantially higher risk of diabetes, heart attack and stroke, heart failure, respiratory diseases and all-cause mortality. This was compared to people who were not obese and had a healthy metabolic profile,” says Ho. “Particularly worth noting is people with metabolically healthy obesity had a higher risk of heart failure and respiratory disease than metabolically unhealthy participants without obesity.”

The number of obese individuals across the world is estimated to have passed 300 million. It is expected the figure will reach one billion by 2030 — a fifth of the global adult population.

The crisis has fueled epidemics in Type 2 diabetes, hypertension, cardiovascular disease and many other serious health problems. Obesity typically leads to metabolic problems including elevated blood sugar, increased blood pressure and insulin resistance. But some of these people have normal readings, healthy amounts of the glucose-controlling hormone, and little or no systemic inflammation.

Metabolically healthy obesity, or being “fat but fit,” was defined as a BMI of at least 30 and meeting at least four of six criteria based on blood pressure and five biomarkers. They included CRP (C-reactive protein), a marker of inflammation, triglycerides or fats, “bad” and “good” LDL (low-density lipoprotein) and HDL (high-density lipoprotein) cholesterol, respectively.

The other was HbA1c (glycated hemoglobin), a measure of average blood glucose over the previous two to three months. It enabled the participants to be categorized as metabolically healthy obese, metabolically healthy non-obese, metabolically unhealthy non-obese, and metabolically unhealthy obese.

Those with metabolically healthy obesity had a 4.3 times and 76 percent greater risk of type 2 diabetes and heart failure, respectively, compared to metabolically healthy non-obese peers. They were 28, 19 and 18 percent more likely to suffer respiratory disease, COPD and heart attacks or strokes, respectively. They were also 28 percent more likely to have heart failure compared to metabolically unhealthy non-obese individuals.

What’s more, among a subset of participants with follow-up metabolic and obesity data, the Scottish team also found a third of those with metabolically healthy obesity at the beginning of the study became metabolically unhealthy in three to five years. The analysis found “fat but fit” individuals were generally younger, watched less television and exercised more, and ate more red and processed meat. They were also more likely to have a degree, were less deprived and were more likely to be female and white than those who were metabolically unhealthy obese.

Earlier this year a study of over 520,000 people in Spain found those who were “fat but fit” had worse heart health. They were up to four and five times more likely to develop diabetes and high blood pressure, respectively. This was compared to those with ‘normal’ weight – who got no exercise.

SWNS writer Mark Waghorn contributed to this report.