Fitness vs fatness: are we focusing on the wrong thing?

The study reviewed data from 20 studies, including nearly 400,000 adults worldwide. Researchers found that fitness levels had a more significant impact on reducing the risk of death from all causes, including cardiovascular disease, than BMI (Body Mass Index). Fit individuals across all BMI categories had similar risks of mortality, while unfit people had 2-3x higher risks, regardless of their weight.

It seems strange to think that according to this study, fit obese individuals had significantly lower mortality risks than unfit normal-weight individuals. Siddhartha Angadi, associate professor at the University of Virginia and corresponding author of the study, summed it up: “Fitness, it turns out, is far more important than fatness when it comes to mortality risk.”

The case for cardiorespiratory fitness is strong

The key thing to understand is that exercise does more than burn calories. It has a beneficial impact on many different systems in the body, improves overall health and reduces the risk of chronic diseases. “Our study found that fit obese individuals had a risk of death similar to that of normal-weight fit individuals and close to one-half that of normal-weight unfit individuals,” Angadi explained.

The research challenges the traditional view that weight loss is the key to improving health outcomes. Weight loss, though beneficial, is notoriously difficult to maintain and can lead to yo-yo dieting, which carries its own health risks. Glenn Gaesser, a co-author of the study, noted: “Most people who lose weight regain it. Repetitive cycles of losing and gaining weight – yo-yo dieting – is associated with numerous health risks comparable to those of obesity itself.”

All body types benefit from fitness

Cardiorespiratory fitness, typically measured by VO2max during exercise stress tests, reflects how efficiently the body uses oxygen during physical activity. The researchers observed the greatest health benefits when sedentary individuals made modest increases in physical activity. Even light exercise, such as brisk walking for 30 minutes a day, can lead to significant reductions in mortality risk.

For those in the bottom 20th percentile of fitness, the benefits of even small increases in activity are significant. “The largest reduction in all-cause and cardiovascular disease mortality risk occurs when completely sedentary individuals increase their physical activity modestly,” said Angadi. This finding reinforces the idea that anyone, regardless of their current fitness level, can take steps to improve their health through exercise.

Rethinking what it means to be healthy

The study’s authors argue that it’s time to shift the focus from weight loss to fitness improvement as the primary health strategy. While obesity is associated with various health conditions, targeting cardiorespiratory fitness may yield better outcomes without the risks associated with chronic dieting or weight regain. This may be great news for those struggling with losing weight. Focusing on fitness may be an easier and more fun goal, especially if you love cycling. This study should be most worrying for those who don’t exercise but have been able to maintain a healthy weight. It seems like physical activity should be the default for everyone.