Don't judge a book by its cover has long been the counsel of school teachers, but a growing body of evidence suggests the expression may apply to people, too. Overweight adults, it turns out can be healthy.
One example is research published in the Journal of American Medical Association (JAMA) which followed 2,600 adults (60 and over) for 12 years to observe the link between weight, fitness, and mortality.

In one study published in the Journal of American Medical Association (JAMA), fitness level, regardless of body mass index (BMI), was the strongest predictor of mortality risk. Those who fell below determined fitness levels—overweight or not—were at highest risk.

Physical activity is essential regardless of a person's size, says Anne VanBeber, PhD, RD and chairperson of nutritional sciences at Texas Christian University in Ft. Worth, Texas. "The thinking needs to change from: 'I need to lose weight' to 'I need to get fit'." VanBeber believes that the number on a scale only tells part of the story. "Weight is just one indicator of well-being. It should not be considered a snapshot of a person's health."

Almost every home has a body weight scale, but that won't tell you if your weight is fat or muscle. "People often get discouraged when they start to exercise and don't see much movement on the scale," VanBeber explains. "If you increase your muscle mass, your metabolism will increase, and you'll be more fit. But remember, muscle weighs more than fat."

To measure your progress, measure your body's composition. If you lose 10 pounds but gain 20 pounds of muscle, you may not like the number on the scale, but you'll look a lot better.

Don't Just Step on a Scale

There are several ways to calculate body composition. Here, the most common and accessible.