Sounds kind of like a dumb question, right? But I seem to be the world champ of stupid question asking lately so I’ll fire away with this one. How much should I weigh? It all started when I was in the gym this week and unexpectedly weighed in two pounds lighter after a wonderful weekend of gluttony. It felt good but I wondered was this really a good result??? What SHOULD I weigh? Am I setting the bar too high? Am I setting the bar too LOW? Let’s look closer at what’s out there…
BMI – what is body mass index?
If you type “body mass index” in Google, you get roughly 68 bazillion hits (plus or minus). Clearly, there are many different opinions out there. BMI takes into account height and weight. Said another way, BMI attempts to assess your weight in the context of your height. Someone who weighs 150lbs and is six feet tall will have a lower BMI (20.3) than someone weighing in at 150lbs and five feet tall (29.3). There are many online BMI calculators out there to try including this one if you are interested in calculating your BMI.
What do these numbers mean? Below are the current BMI weight classifications/categories (courtesy of NHLBI):
- Underweight < 18.5
- Normal weight: between 18.5 – 24.9
- Overweight: between 25 – 29.9
- Obese >30
In this example, the shorter person would be overweight, while the taller person would be considered normal weight.
Limitations of BMI
Ok. If it’s as simple as plugging values into a little calculator and finding out where you fit in, why all the controversy? BMI calculations are not without their flaws…mainly that weight is influenced or impacted by more than just height. Consider the example of a five foot tall person who weighs 150lbs. What if it’s a man? Woman? Child? Elderly person? Pregnant? Whether the person would be really considered overweight depends on the context which BMI alone cannot factor in. Of course we could use more customized or specific BMI tables (ex. Elderly, women, etc) to determine whether someone is overweight, but I think you get the idea that there are complexities that just can’t be captured by BMI.
Beyond BMI, a few other measures can be used and include waist-to-hip ratio, body fat percentage among others and there are many articles summarizing weight metrics to dig deeper into for more info.
At the end of the day, there doesn’t seem to be a great consensus. Clearly, there are many studies linking obesity to a whole host of conditions so it shouldn’t be ignored. But as it relates to MY PERSONAL WEIGHT LOSS JOURNEY I’ll settle for continued progress and trying to get within 10% of my pre-pregnancy weight. If you feel good, you look good!