First it was the tape measure and the number on the scale. Then came Body Mass Index (BMI)—both measurements that purport to tell you how healthy you are. Surely, if doctors and fitness trainers are using these tools, they must be effective. Right? Wrong! No wonder we’re confused about how much we should weigh to get and stay healthy.

“A healthy weight isn’t…a number on a scale, a category in the BMI, a specific shape, [or] fitting into specific size clothes,” says Marsha Hudnall, MS, RDN, CD of Green Mountain at Fox Fun, a non-diet weight-loss retreat. (“Defining healthy weight: what it is and what it isn’t,” http://www.fitwoman.com, 1/18/06) Rather, a healthy weight must be decided through a person-by-person assessment, not by across-the-board measures.

But, what about BMI? Don’t those calipers accurately measure body fat? Hudnall says, “The BMI derives from an almost 200-year-old classification system that was initially intended to be used to assess populations of people, not individuals. In the latter half of the last century, it morphed into something that was used to judge individual health based on height and weight, ignoring the many other factors that affect health. But even looking at health based on height and weight, research clearly shows that using BMI is misguided. A meta-analysis of 97 studies of a total of almost 3 million people, published in 2013 in the Journal of the American Medical Association, showed that people who fall into the overweight category are actually the longest-lived.” (Katherine M. Flegal, PhD; Brian K. Kit, MD; Heather Orpana, PhD; Barry I. Graubard, PhD. Association of All-Cause Mortality With Overweight and Obesity Using Standard Body Mass Index Categories A Systematic Review and Meta-analysis. JAMA. 2013 Apr; 309(1):71-82.)

Hudnall asserts that a healthy weight is “individual, affected by more than diet and exercise, and an outcome, not a goal.” It comes from engaging in certain healthy practices rather than in one particular behavior. Health is an outgrowth of lifestyle choices and “a healthy weight is best achieved when it happens naturally, as a result of adequate self-care.” This is a crucial point: health grows out of self-care and self-care is all about enhancing health. We take care of what we love and value.

Hudnall points out that many people get confused about beauty and health. Our culture has certain beauty standards (eg, thin), which are different than what makes for good health. Remember, thin doesn’t equal health and health doesn’t equal thin. Here’s the Green Mountain definition of healthy weight: it is “your natural weight, which is largely determined by your genetics. If you come from a family of larger or smaller people, you are likely to be larger or smaller.” When you’re taking the best care of your mind/body that you possibly can, you’re most likely to arrive and remain at a healthy weight.