For better health and a longer lifespan, exercise is more important than weight loss, especially if you are overweight or obese, so one interesting new review the links between fitness, weight, heart health and longevity.
The study, which analyzed the results of hundreds of previous studies of weight loss and exercise in men and women, found that obese people tend to lower their risk of heart disease and premature death much more through fitness gains than through weight loss or dieting.
The review adds to the growing evidence that if we are also active enough, most of us can be healthy at any weight.
I’ve written about the science of exercise and weight loss many times, a lot of which, frankly, is daunting if your goal is to get leaner. This previous research shows overwhelmingly that people who start exercising rarely or not at all lose much weight unless they also reduce food intake significantly. Exercise generally simply burns too few calories to support weight loss. We also tend to compensate for some of the meager calorie consumption from exercise by eating more or exercising less afterwards, or by unconsciously turning back our body’s metabolic processes in order to reduce total daily energy expenditure.
Glenn Gaesser, a professor of exercise physiology at Arizona State University in Phoenix, is well versed in the inadequacies of fat loss workouts. For decades he has been studying the effects of physical activity on body composition and metabolism as well as their endurance with a special focus on obese people. Much of his research to date has highlighted the futility of weight loss workouts. For example, in one experiment in 2015, he supervised 81 sedentary, overweight women who began a new routine of walking for 30 minutes three times a week. After 12 weeks, some of them had lost some body fat, but 55 of them had gained weight.
Significant health problems
However, in other studies from Prof. Gaesser’s laboratory, overweight and obese people with significant health problems, including high blood pressure, poor cholesterol profiles, or insulin resistance, a marker of type 2 diabetes, showed significant improvements in these conditions after starting exercise, whether or not they have any weight lost or not. When Prof. Gaesser saw these results, he began to wonder whether fitness could enable obese people to enjoy healthy metabolic health regardless of their body mass and possibly live as long as leaner people – or even longer if the lean people happen to be no more time have form.
For the new study published in iScience this month, he and colleague Siddhartha Angadi, professor of education and kinesiology at the University of Virginia at Charlottesville, began searching research databases for previous studies on diet, exercise and fitness, metabolic health and longevity . They were particularly interested in meta-analyzes that pull together and analyze data from several previous studies so that researchers can see the results from far more people than most individual studies of weight loss or exercise, which are typically small in scale.
At the end there are more than 200 relevant meta-analyzes and individual studies. Then they set out to see what all of this research, involving tens of thousands of men and women, most of whom were obese, had on the relative benefits of losing weight or getting fit for improving metabolism and longevity. In fact, they asked if someone who is heavy gets better health from losing weight or getting up and moving.
They found that the competition was not close.
“In a direct comparison, the benefit from improving fitness was far greater than from losing weight,” said Prof. Gaesser.
Overall, the studies they cite show that sedentary, obese men and women who start exercising and improving their fitness can lower their risk of premature death by as much as 30 percent or more, even if their weight doesn’t drop. That improvement generally puts them at lower risk of early death than people who are considered to be of normal weight but not in good shape, Prof. Gaesser said.
Conversely, when heavy people lose weight through diet (not disease), their statistical risk of dying young typically drops by about 16 percent, but not in all studies. Some of the research cited in the new review shows that weight loss in obese people does not reduce the risk of death at all.
However, the new review was not designed to determine exactly how exercise or weight loss affects the longevity of people with obesity. But in many of the studies they looked at, Prof. Gaesser said that people who had lost pounds from dieting regained them and then tried again a yo-yo approach to weight loss, which often leads to metabolic problems like diabetes and high cholesterol and lower life contributes to expectation.
Movement, on the other hand, combats the same conditions, he said. It can also unexpectedly rebuild people’s fat stores. “People with obesity usually lose some visceral fat when they exercise,” he said, even if their overall weight loss is negligible. Visceral fat, which builds up deep in our bodies, increases the risk of type 2 diabetes, heart disease, and other conditions.
Some of the studies they cite find that exercise alters the molecular signals in other fat cells too in ways that can improve insulin resistance, regardless of how much weight someone is carrying. “It looks like exercise will make you fitter,” said Prof. Gaesser.
According to Gaesser, the most important finding of the new review is that you don’t have to lose weight to be healthy. “In terms of mortality risk, you are better off increasing your physical activity and fitness than you are doing deliberately losing weight,” he said. – This article originally appeared in the New York Times