Exercise or weight loss, which is a better bet for health and longevity? We’ve explored the benefits of both in this newsletter.

The guidelines for obesity management have long focused on weight loss through dieting and increased physical activity. And in recent years, some scientists have suggested a “fat-but-fit” approach with increased physical activity levels and improving cardiorespiratory fitness as the primary focus.1

But does this approach work to lower the risk of cardiovascular disease and mortality in the absence of weight loss?

Obesity is an issue of great concern as more than one-third of adults in the United States are obese and at greater risk of death.2

According to the Centers for Disease Control and Prevention (CDC), obesity is linked to a host of conditions including heart disease, stroke, type-2 diabetes, and certain types of cancer. These are among the leading causes of preventable, premature death.

The urgent call for weight loss sounds quite clear-cut until you consider…

The Yo-Yo Dieter’s Dilemma

As any habitual dieter can attest to, the reduced calorie intake necessary for weight loss is hard, and even harder to maintain. What’s more, repeated gaining and losing – called weight cycling – may also bring about an array of health problems.3

Recently researchers from Arizona State University in Phoenix looked at how best to reduce the risk of obesity-related health conditions and mortality.

The review, published in the journal iScience, compares the effectiveness of physical activity and cardiorespiratory fitness with that of weight loss.4

Tipping the Scales

Glenn Gaesser, a professor of exercise physiology at Arizona State University in Phoenix, has studied the effects of physical activity for decades.

In the past, Dr. Gaesser conducted research that showed overweight and obese people with significant health problems, such as high blood pressure, poor cholesterol profiles or insulin resistance, had significant improvements in those conditions after they started exercising. And this occurred whether they dropped any weight or not.

These findings piqued Dr. Gaesser’s curiosity. Could physically active overweight people enjoy sound metabolic health? And could they potentially live just as long as thinner people who were out of shape?

The researchers poured over more than 200 relevant meta-analyses and individual studies. They wanted to compare the relative benefits of losing weight or getting physically fit for improving health and longevity.

Turns out, the contest wasn’t even close.

“Compared head-to-head, the magnitude of benefit was far greater from improving fitness than from losing weight,” Dr. Gaesser said.

Exercise Lowers Risk of Death 30 Percent or More

The researchers found that sedentary, obese men and women who start to exercise and improve their fitness levels can lower their risk of premature death by as much as 30 percent or more. And that’s without shedding a pound!

Researchers say fitness improvement put these folks at a lower risk of early death than their peers who are considered normal weight but out of shape. Interestingly, the analysis found that focusing on just weight did not change the risk much. In fact, the risk dropped about 16 percent, but not across all studies.

Dr. Gaesser cautioned against the yo-yo approach to weight loss, which he says may contribute to metabolic problems and lower life expectancy. Conversely, he says, exercise can combat those same issues. In other words, Dr. Gaesser believes that you don’t necessarily have to lose weight to be healthy.

“You will be better off, in terms of mortality risk, by increasing your physical activity and fitness than by intentionally losing weight,” he concludes.

My Takeaway

I’m a big believer in physical activity. Exercise is essential to our health and these findings reinforce just how essential exercise really is. That being said, don’t take the new research as a hall pass to follow a poor diet and not work on your waistline. That’s because this new study does not unravel all of the medical ramifications of obesity. While I discourage crash-dieting of any ilk, I advocate adopting lifelong mindful eating habits coupled with regular physical activity to manage weight and promote a healthy life.


  1. https://bjsm.bmj.com/content/52/3/151.short
  2. https://www.cdc.gov/obesity/data/adult.html 
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4241770/ 
  4. https://www.cell.com/iscience/fulltext/S2589-0042(21)00963-9?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS2589004221009639%3F
    showall%3Dtrue