Figuring out what the scale should say, not what you want it to, is worth the trouble You probably have the number in your head right now. Most of us do. It’s the weight you’d like to weigh, if you had your druthers. It may be a long-ago weight — before you had kids, before you were married, even when you were still in school. Or it might be more recent — the number on the scale when you were training for, say, your first marathon in your 30s or when you did aerobics nearly every day. It could be time, though, to put that fantasy number to bed and focus on reaching or maintaining a healthy weight — the figure at which we feel strong, energetic, like our best self. So what is that number? Good question. Figuring it out is not an exact science, says Lisa Young, an adjunct professor at New York University and author of The Portion Teller Plan: The No-Diet Reality Guide to Eating, Cheating, and Losing Weight Permanently. That said, “it’s important to strive for something that’s realistic and healthy, and that’s usually a Body Mass Index [BMI] of 18.5 to 25,” which is considered normal weight, says Young. But BMI Has Its Limits No doubt you’ve heard of BMI, a fairly simple number crunch of weight and height to estimate how much fat a person has. Though widely-used, it’s not a perfect way to measure the link between weight and health, says Dr. Rexford S. Ahima, professor of medicine at the University of Pennsylvania Perelman School of Medicine. Years ago, “the World Health Organization came out with some standards and [said that] if you have a BMI of 30 or higher you...