Recent Headlines Suggest Being Both Fat and Fit Is a Myth. It’s Not That Simple
A new study of data from 527,662 adults reports that those who are overweight or obese are at a significantly higher risk for cardiovascular disease regardless if they are otherwise “regularly active.”
This is the latest study in a 20-year medical debate over whether someone can be both “fat and fit.”
This study did not actually measure or look at fitness, however, but rather if people reported meeting the minimum exercise requirements. Other studies that have measured fitness have found that being fit has significant health benefits regardless of weight.
“‘Fat but fit’ is a myth.” “Overweight and healthy is a big fat lie.”
Those and other headlines rang out recently as mainstream news outlets picked up the latest study on BMI, physical activity, and risk of cardiovascular disease. The researchers’ goal in this study, which was published in the European Journal of Preventive Cardiology, was to examine the notion of whether one can be “fat but fit,” a debate that has raged in the medical community for more than 20 years. And the study concluded that a physically active lifestyle cannot protect your heart against the negative impact of being overweight.
This particular study pulled data from 527,662 adults from Spain, with an average age of 42, who were insured by an occupational risk prevention company. They were put into groups according to their weight, based on BMI, and their activity levels. About 42 percent of the participants were normal weight with a BMI of 20 to 24.9; 41 percent were overweight with a BMI of 25 to 29.9; and 18 percent were classified as obese with a BMI of 30 or above.
Activity levels were based on the World Health Organization (WHO) physical activity guidelines, which recommend performing at least 150 minutes of moderate physical activity or at least 75 minutes of vigorous activity (or some combination of the two) a week.
People who said they didn’t exercise at all were considered inactive. Those who reported some activity, but didn’t meet the minimum WHO requirements, were considered insufficiently active. Those who met the WHO minimum levels were considered regularly active. Overall, 63.5 percent were inactive; 12.3 percent were insufficiently active, and 24.2 percent were regularly active.
Then the researchers examined the participants’ cardiovascular risk factors by categorizing them for high cholesterol, high blood pressure, and diabetes, all of which raise the risk for heart attack and stroke.
After crunching the data, the researchers found that being active was definitely healthier than not being active. Those who reported some physical activity were less likely to have any of the three risk factors compared to their completely sedentary peers. Those who were more active also had a lower risk of high blood pressure and diabetes.
However, those who were in the overweight or obese categories were at a significantly higher risk for cardiovascular disease regardless if they were otherwise “regularly active.”
Those who were regularly active but obese were twice as likely to have high cholesterol, five times as likely to have high blood pressure, and were four times more likely to have diabetes compared to the participants who were normal weight, but didn’t meet the minimum activity guidelines. Those in the overweight category also were at an increased risk despite their activity level, though the increases in cardiovascular risk were less dramatic.
There’s just one problem: this latest study didn’t actually measure fitness.
Cardiorespiratory fitness counts
It’s hard to describe individual fitness by the WHO guidelines alone. Walking the dog for 20 minutes (which is a perfectly great activity!) checks the box for meeting those requirements; so does doing short interval workouts every day. But a study that just looks at meeting the guidelines doesn’t give a clear picture of what people are actually doing; let alone how fit or not they are.
It’s also challenging to assert that you can’t be fit if you’re fat—anyone who is clinically defined as overweight, but has run marathons, can tell you that. In fact, research that investigates cardiorespiratory fitness specifically (not just whether or not you get the minimum amount of active minutes according to the guidelines) paints a different picture.
Specifically, a 2014 meta-analysis titled “Fatness vs. Fitness on All-Cause Mortality,” published in Progress in Cardiovascular Diseases investigated the impact of your cardiorespiratory fitness, as measured by VO2 max, and your BMI on risk of death from any cause. It concluded that risk of death was dependent on your fitness levels, not your BMI.
That research concluded that people who were fit—whether they were normal weight, overweight, or obese—all had similar risks of dying from any cause. On the other hand, unfit people had twice the risk of dying of any cause regardless of their BMI.
“Optimal body weight is different for each individual,” says exercise scientist Vaughn Barry, Ph.D., of Middle Tennessee State University who was the lead author of the 2014 Fatness vs Fitness study. “You could have a BMI higher than what the charts say is optimal and be running 18 miles a week and be healthy. Being fit removes and lowers a lot of health risks.”
Recent research also shows that more exercise means more protection (a.k.a. exceeding the minimum requirements might be the ticket for some people). In a 2021 study of more than 90,000 people published in PLOS Medicine, researchers found that those who logged the most physical activity—measured as moderate-intensity, vigorous-intensity, or as total volume—had about a 60-percent lower risk of cardiovascular disease than those who logged minimal amounts of activity.
Other research has found that for every 1 MET, or “metabolic equivalent,” increase in exercise capacity, the risk of early death from any cause decreases an average of 17 percent; that goes up to 25 percent for people who are categorized as obese. By the time you reach 7.5 METs of exercise capacity, risk of early death from any cause is similar to those of normal weight and those classified as obese, according to a study published in the American Journal of Hypertension.
Running a 12-minute mile is categorized as an 8 MET activity according to the scientific Adult Compendium of Physical Activities, which assigns MET intensities to nearly every physical activity.
That study concluded, “These findings suggest that it is more beneficial to be fit and overweight or obese rather than normal weight and unfit.”
Body composition matters
That’s not to say there aren’t inherent risks that are associated with high levels of body fat, particularly the kind that sits deep in your abdomen—that can cause inflammation in the body and is among the factors that can increase your risk for cardiovascular disease, diabetes, and other chronic diseases. (It is also worth noting that BMI doesn’t tell you anything about body composition; nor does it accurately reflect whether athletes—who have high amounts of muscle—are actually “overweight.”)
Losing body fat and increasing muscle can definitely improve health in some people, as can eating well, reducing stress, and getting quality sleep. In the big picture, though excess fat can pose health risks, you can still be fit, and yes, you can still be healthy. The most important thing is to keep moving and work with a health professional who will help you keep tabs on all the rest.
“Fitness versus fatness has been an academic debate over the last 20 years,” Tim Church, M.D., M.P.H., Ph.D., of Pennington Biomedical Research Center at Louisiana State University, one of the country’s leading physicians in exercise and obesity research, tells Bicycling. “What is not debatable is the power of movement at any weight. No matter your age, weight, or health conditions, regular physical activity promotes better health and general quality of life.”
Bottom line: It’s clear that meeting the minimum WHO exercise guidelines was not especially protective for those in the higher BMI categories in this study. But the study doesn’t shut the door on the decades-long debate as some headlines suggest. One study can never do that. It also doesn’t conclude that you can’t be “fit and fat” or that “fitness” itself is not especially protective, as other studies have over the past 20 years.
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