By Lorie A. Parch
Originally Posted On July 2, 2014
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.
Simply put, BMI is most useful in predicting health problems primarily in those who are very overweight; if you're not, it's not nearly as helpful.
What's Your Waist Size?
So if computing your BMI is not an ideal way, on its own, to figure out your goal weight for good health, what are better options? The short answer is that the best, most accurate measure for you is a combination of metrics.
Include BMI, but also get out the tape measure and put it around your waist, says Ahima. "The easiest method to get a sense of fat distribution is waist size," he explains, noting that men should have a waist size of under 40 inches and women should have a waist under 35 inches for good health. "How often has your doctor measured your waist? Almost never, but it's a better predictor than BMI."
To measure it accurately, Ahima says you should stand up tall, put your fingers on the top of your hip bone, and loosely place the measuring tape there, measuring your waist from that point. "Breathe in and out and then you measure," he says.
Where you store fat on your body is a decent fortune-teller for health problems, it turns out. "We know that women have more fat in their thighs and buttocks and men get more belly fat," Ahima notes. "So people have argued that we need to take into consideration the shape of the person."
A fairly new measure, called A Body Shape Index (ABSI), does just that and has BMI and waist-size built into its calculation. The Index isn't available for clinical use yet, says Ahima, it's only used in research. But it could eventually come to a doctor's office near you. A February 2014 study in PLOS ONE found that ABSI was a more accurate predictor of death risk than BMI.
Setting a Reachable Goal
Once you know your BMI and your waist size, it's time to talk to your doctor. "[A physician can] consider how much muscle a person has, their health status and their family history," Ahima says. "BMI is useful as a trend, so if a person had a BMI of, let's say, 25 and then five years later it's 30, clearly there's something wrong. What you're looking for is a trend rather than an ideal weight, which doesn't really exist because people are so variable."
Once you've had the conversation with your physician about what's a healthy weight for you, you're ready to target a number, or at least a range.
"It's important to strive for something that's realistic," says Young. "I see people in their 40s and 50s all the time who struggle with, 'I'd love to weigh what I weighed at X time.'"
Young likes to set halfway goals with her clients. "If they weigh 175 pounds, let's get them down to 150, and we'll see," she says. "Then we can re-assess. You're less likely to fail when you're able to get to something. That's very important."
Here are Young's top tips for losing pounds to get to a healthy weight: