Fit but Fat: Fact or Fiction?
The fit but fat concept posits that you can compensate or attenuate the cardiovascular, metabolic, and mortality risk associated with obesity by improving your cardiovascular fitness. Though there’s no general consensus about the fit but fat concept among scientists and physicians, it’s an area that has stirred debate and ongoing research.
We’ve all been hearing constant chatter from news sources about the rising obesity epidemic. To clarify, there’s no question that those who are obese do benefit their health from improving their cardiovascular fitness in terms of reducing these risk factors, but can you actually be fit AND fat?
First off, I would like to point out the obvious fact that we as human beings come in all different shapes and sizes. And let’s be honest here, we’re all sensitive about our weight. I can look in the mirror and think that I’d like to lose a few pounds, but that’s vastly different from someone telling me that I need to. Say what?
Fit but Fat?
The fit but fat concept seems to have its origins in a study published in 1999 in the American Journal of Clinical Nutrition. The observational study followed a cohort of nearly 22,000 men for a duration of 8 years. The authors concluded that the health benefits of leanness were limited to fit men. What’s more is that the study found that fit men with large waist girths (> or= 99 cm) had a lower risk of all-cause mortality than unfit men with low waist girths (<87 cm).
Score one point for the fit but fat movement… Not too fast though! This study was criticized for being limited in 2004 in a study published in the New England Journal of Medicine. What’s more is that obesity itself has been associated with an increased risk for a number of health conditions ranging from cardiovascular disease, diabetes, certain types of cancer to arthritis.
One important distinction that should be made is between obesity and merely being overweight. Obesity is defined as having a body mass index greater than 30. For those that are merely overweight, they can breathe a sigh of relief as no associated between being simply overweight and an increased risk of mortality has been found in studies. [1,2].
One limitation in studies of this nature though is that in using BMI, they’re unable to discriminate between those who have larger amounts of lean muscle mass. In fact, a recent study published in the Archives of Internal Medicine found an association between abdominal obesity and all-cause mortality in a large U.S. cohort.
What Proportion of the US Population is ‘Fit but Fat?’
One study estimates that the proportion of the US population that meets the criteria of ‘fit and fat’ is approximately 8.9%. The same study found that being obese is associated with a 9.2% lower V02 max (measure of cardiovascular fitness) compared to normal weight.
Weight Loss vs. Exercise for Lowering Inflammation?
In a very recently published study (Obesity), the authors compared the effects of diet and exercise (both resistance training and cardiovascular) on markers of inflammation. Surprisingly, the authors found that weight loss itself was more effective than exercise on reducing markers of inflammation:
“In conclusion, weight loss was associated with decreases in MOI (markers of inflammation). The effect of weight loss appeared to be mediated by changes in total fat mass or IAAT (intra-abdominal adipose tissue). Addition of exercise did not alter the response, suggesting that weight loss has a more profound impact for reducing MOI in overweight women than exercise.”
In a Nutshell:
Though the debate over being fit but fat is far from over, the research in this area points to a few simple conclusions. First, for those that are obese, there are numerous health benefits associated with exercise and improving their cardiovascular fitness. Yes, it’s better to be fit and fat, than unfit and fat.
Secondly, the research indicates that it’s far healthier to be lean and fit than fit and fat. Losing weight can play a role in reducing markers of inflammation that confer disease risk.
However, for those who are unable to lose weight, it’s important to not only get or stay fit, but still find a way to love yourself regardless of your size or shape.