4 ms·

I would say it is useful only to gauge obesity in a large population (where only a marginal percentage has such a high muscle mass that a high BMI does not repr

I would say it is useful only to gauge obesity in a large population (where only a marginal percentage has such a high muscle mass that a high BMI does not represent obesity).

kbenson 6y ago
But how many people does having both muscle and fat push them from the overweight category to the obese category? At 5'-9" the overweight category starts a little over 169 lbs and the obese category starts just above 203 lbs. Given that as a teenager I was well into the overweight category with a six-pack and very little fat from an active lifestyle and playing a lot of basketball multiple times a week, I could easily see how just eating more might put be closer to obese while still having less fat than one would expect from that designation. That's not to deny Americans have a problem with weight. I just think it's counter-productive to use metrics that people can easily see are problematic when trying to make a valid point. Using controversial measurements because the are easily available is lazy.
- ThePadawan 6y ago
  The level of fitness you describe would put you in the top 2% of people I have ever met. I think that margin of error is acceptable compared to the ease of use of the BMI.
  - kbenson 6y ago
    I did not feel overly fit. I was definitely not as fit as the people that played a sport competitively. I hung out with friends, ate (a lot of) fast food, and didn't do much outside of school. I did have a "weight training" class a few times a week, where we ran a mile and then I played basketball the whole time. A total of about five hours of exercise a week, and not being sedentary, definitely not an outlier for many teenagers. Yet still considered overweight? The problem is that the BMI probably matches fairly well to a specific slice of the population. Maybe males 25-40. It likely loses accuracy of meaning the farther in age either direction you go, as well as the more different you are from the optimal subgroup. This is only barely noted in most cases (it's alluded to here in this article that Asian people might see problems at different BMI numbers). What about women vs men? What about the young and elderly? As a metric, BMI is poorly understood by the public, and this poor understanding is targeted and capitalized on by different studies. All it does is cloud our view of what's really going on.

I would say it is useful only to gauge obesity in a large population (where only a marginal percentage has such a high muscle mass that a high BMI does not represent obesity).

kbenson 6y ago

But how many people does having both muscle and fat push them from the overweight category to the obese category? At 5'-9" the overweight category starts a little over 169 lbs and the obese category starts just above 203 lbs. Given that as a teenager I was well into the overweight category with a six-pack and very little fat from an active lifestyle and playing a lot of basketball multiple times a week, I could easily see how just eating more might put be closer to obese while still having less fat than one would expect from that designation. That's not to deny Americans have a problem with weight. I just think it's counter-productive to use metrics that people can easily see are problematic when trying to make a valid point. Using controversial measurements because the are easily available is lazy.

ThePadawan 6y ago
The level of fitness you describe would put you in the top 2% of people I have ever met. I think that margin of error is acceptable compared to the ease of use of the BMI.
- kbenson 6y ago
  I did not feel overly fit. I was definitely not as fit as the people that played a sport competitively. I hung out with friends, ate (a lot of) fast food, and didn't do much outside of school. I did have a "weight training" class a few times a week, where we ran a mile and then I played basketball the whole time. A total of about five hours of exercise a week, and not being sedentary, definitely not an outlier for many teenagers. Yet still considered overweight? The problem is that the BMI probably matches fairly well to a specific slice of the population. Maybe males 25-40. It likely loses accuracy of meaning the farther in age either direction you go, as well as the more different you are from the optimal subgroup. This is only barely noted in most cases (it's alluded to here in this article that Asian people might see problems at different BMI numbers). What about women vs men? What about the young and elderly? As a metric, BMI is poorly understood by the public, and this poor understanding is targeted and capitalized on by different studies. All it does is cloud our view of what's really going on.