Fat But Fit: Is It Possible?

Overweight Woman Jogging
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Most of us are well aware that excess body fat is bad, all too often, for our health as well as our self-esteem. But the idea that being overweight is consistently bad for health has been challenged over recent years in several ways, and for several reasons.

The Obesity Paradox

First, large studies have raised the possibility that being a bit overweight might actually predict better health outcomes than being truly “lean.” This has been referred to as “the obesity paradox,” the paradox being that an apparent excess of body fat actually confers benefit rather than harm.

This appears not to be true, however; there really is no obesity paradox. Rather, many studies have failed to differentiate between people healthy enough to keep weight on, and the early stages of serious illness that tend to cause weight loss in older people. What has been reported as an obesity paradox seems to be the furthest thing from paradoxical: people who are sick are more likely both to lose weight, and die prematurely, than people who are basically healthy.

Second, there’s the observation that not all varieties of obesity confer comparable risk. This is certainly true. In particular, young women who gain excess weight are particularly prone to store fat in the lower extremities. In contrast, and because of the actions of hormones like testosterone and estrogen, men and women after menopause are more prone to store fat in the belly, where it tends to do much more metabolic harm.

There are also whole ethnic groups, such as natives of India, who may be particularly prone to fat deposition in the belly, and most importantly, in the liver, where it contributes directly to insulin resistance.

Because some people can store excess body fat with very limited impact on metabolic risk markers, this association has contributed to the argument that overweight, per se, may not always be bad for health.

Can Fitness Counterbalance Obesity?

Finally, there has long been the argument that fitness can potentially overcome fatness.

If, in other words, you are obese but fit, the fitness may fully defend against any potential harms of fatness.

There are at least two reasons why this claim is important. The first is that for reasons of genes and other factors both known and unknown, some people gain weight with extraordinary ease, and lose it with extraordinary difficulty. I have met some of these people in my practice over the years. For people in this group, it is possible to exercise a lot, be quite fit, and still carry “excess” body fat. The contention that fitness can counter fatness originated with this very experience, and is a welcome idea among the weight loss-resistant.

The second reason is that obesity bias remains a major problem in our culture. Obesity, despite all the reasons we have to know otherwise, still often conjures thoughts of gluttony and laziness. Establishing that some overweight people are quite fit, and thus the very opposite of lazy, is a useful rebuttal to this popular fallacy.

Unfortunately, however, the idea that fitness can compensate fully for fatness with regard to health outcomes appears—like the obesity paradox—to be untrue.

The Research

A study reported in the European Heart Journal in 2017 examined the associations between both body weight and metabolic markers, and coronary heart disease in over a half million people followed for more than a decade.

The authors found, quite simply, that the presence of metabolic risk factors, like high blood pressure or abnormal blood levels of lipids or glucose, increased the risk of heart disease independently of weight. However, they also found that weight—an elevated body mass index—increased the risk of heart disease independently of these risk factors. In other words, when lean and overweight people had identical values for blood lipids, blood glucose, and blood pressure, the overweight people were still significantly more prone to heart disease.

This is not the first time research has served up a rejoinder to the “fat but fit” concept.

A Korean study published in the Journal of the American College of Cardiology in 2014 told us much the same: excess body fat elevates cardiovascular risk even when conventional markers of that risk are all within normal ranges. In that study, heart disease risk was assessed by measuring calcium in coronary arteries.

There is a bit of a silver lining in all this if you happen to be someone who carries extra weight despite fitness and routine exercise. While lean and fit is the healthiest combination, the combination of fatness and fitness is better than the absence of both. In other words, thin people with obvious metabolic risk factors for heart disease fare worse than overweight people without those markers.

The Takeaway

As for a take-away message, I think it is much the same now as it was in 2014, the last time this topic generated headlines. Don’t focus on your weight, per se. Be active, because it’s good for you, and because it feels good. Eat well for the same reasons. Remember that it is far easier to out-eat exercise than to out-exercise a bounty of tasty calories, so be sure to choose foods wisely.

For the most part, what makes you truly fit also defends against fatness—maybe not perfectly, but well enough. The best strategies for lasting weight control are strategies for promoting health, too. Make good use of your fork, and your feet—and claim the dual benefits of less fatness, more fitness.

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