For better health and a longer life span, exercise is more important than weight loss, especially if you are overweight or obese, according to an interesting new review of the relationships among fitness, weight, heart health and longevity.
The study, which analyzed the results of hundreds of previous studies of weight loss and workouts in men and women, found that obese people typically lower their risks of heart disease and premature death far more by gaining fitness than by dropping weight or dieting.
The review adds to mounting evidence that most of us can be healthy at any weight, if we are also active enough.
I have written about the science of exercise and weight loss, much of which is, frankly, dispiriting, if your goal is to be thinner. This past research overwhelmingly shows that people who start to exercise rarely lose much, if any, weight, unless they also cut back substantially on food intake. Exercise simply burns too few calories, in general, to aid in weight reduction.
We also tend to compensate for some portion of the meager caloric outlay from exercise by eating more afterward or moving less, or unconsciously dialing back on our bodies’ metabolic operations to reduce overall daily energy expenditure.
Glenn Gaesser, a professor of exercise physiology at Arizona State University in Phoenix, is well-versed in the inadequacies of workouts for fat loss. For decades, he has been studying the effects of physical activity on people’s body compositions and metabolisms, as well as their endurance, with a particular focus on people who are obese. Much of his past research has underscored the futility of workouts for weight loss. In a 2015 experiment he oversaw, for instance, 81 sedentary, overweight women began a new routine of walking three times a week for 30 minutes. After 12 weeks, a few of them had shed some body fat, but 55 of them had gained weight.
In other studies from Gaesser’s lab, though, overweight and obese people with significant health problems, including high blood pressure, poor cholesterol profiles or insulin resistance — a marker for Type 2 diabetes — showed considerable improvements in those conditions after they started exercising, whether they dropped weight or not.
Seeing these results, Gaesser began to wonder if fitness might enable overweight people to enjoy sound metabolic health, whatever their body mass numbers, and potentially live just as long as thinner people — or even longer, if the slender people happened to be out of shape.
So, for the new study, which was published this month in iScience, he …….