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It’s a 20+ year old metric that doesn’t work very well for the individual. There are a lot of outliers and not every doctor takes that into account. It works as a general indicator, but not a be all end all.
The latest research I read indicated that waist size (gender specific) is a better metric, as abdominal fat in particular tends to indicate negative health effects, whilst fat in other areas did not.
Edut: It’s 50 years old apparently
Studies have shown a person’s risks of certain health problems increases at a certain BMI, regardless of sex. Remember, BMI is a health thing - not what weight you “look good” at, nor does it indicate one has a muscled or “fit” body - just that you’re within a weight range that has proven to be lower-risks for certain health problems. I’d guess the reason for scale being the same is because while men have more muscle and denser bones, women can and should have more fat (a healthy woman should have 10-31% body fat, a healthy man only 2%-24%), and so it balances out. (edit: the lower number for body fat is the “essential” number. Realistically, it’s more like 14%-31% for women and 6%-24% for men).
For children and teens, they do have a different scale for boys and girls, though.
Because it’s a population metric that is extremely easy to catalogue and also hugely accurate for that level of metric. Typically listing a sample correlation coefficient (r) of 0.8 (as high as 0.9 in women in this study).
You don’t really get much better than that at those levels of population. Even on the individual it holds up fairly well. Obviously if you’re super yoked or you hold very little visceral fat your doctor will realize. It’s just an indicator.
I see many criticisms of BMI as those overestimating what it can do. Like getting angry at a rule for not telling you how many apples are in your tree.
I believe it’s based off of when people are at higher risk of getting diseases. It just so happens that men and women start getting diseases at the same weights. I vaguely remember reading this somewhere so idk how reliable it is
Use it as a general scale, it won’t work for absolutely everyone or be incredibly accurate. Science will never be perfect and I wish people used logic when thinking about this sort of thing, of course making a scale that covered absolutely everything would be great but it’s just not going to happen. In my course they suggested using it as a starting point/ big generalisation and that’s it.
I was listening to a medical podcast and they were chatting about BMI.. basically when the ‘medical professionals’ made a decision on what is overweight, obese, underweight they just made it up. So BMI over 25? According to that you’re overweight, BMI over 30 you’re obese.. it takes nothing into account. You could be a professional rugby player that is classed as obese, it doesn’t account muscle especially when muscle weighs more than fat.
BMI modalities are highly inaccurate and they are rarely used now, outside of the military.
I can speak to that because I am a combat veteran and also a clinical herbalist. So sadly, that’s how “it can be the same”, because they were using inaccurate science back then.
I hope that helps!
I applied for a breast reduction surgery and the government medical people said they won’t consider me if my bmi is over 30. Its good to know that there are quite leanient on the bmi scale but still taking it into consideration as i could also be between 25 and 30 and be generally healthy. The highest weight for me to be in the healthy weight range is 66kg and thats very low for me personally as I am a bigger build than alot of girls i can tell from my broad shoulders. Also bmi was like 34 at the time so i was well over the healthy weight range anyway.
BMI in the overweight and up category is statistically correlated with a lot of different diseases. For example we start screening blood sugars during medical appointments in individuals with a BMI over 25. People like to point out that individuals that are adept weight lifters can fall into the overweight category but wouldn’t be at risk for correlated diseases. They also like to point out that there are individuals that don’t have these diseases that are in these categories. But that doesn’t matter. Physicians need an objective value to start screening certain diseases and a way to tell a patient that it’s in their best interest to lose weight. What is the alternative? “Ma’am I can tell just by looking at you that you need to lose weight to improve your health”? Do you want a physician measuring your waist and limbs with a tape measure and fat calipers for a more accurate body fat % just to rule you in for “the weight loss talk” and a blood glucose measurement? No? Then stop complaining about the BMI. It’s such a ridiculous complaint so many people in the nutrition and body positivity movement like to rail on and the more accurate alternative would be more humiliating to people scared to step on a scale because weightlifters are a BMI outlier
BMI is an actuarial number. It has a purpose in statistical models, but has zero application to an individual because it relies on so few parameters.
BMI is great for telling us that Mississippi is the fattest state in the US, but is terrible about telling us whether a particular 5’10” 175 pound man is overweight. The bigger the group, the more applicable it is.
I’m 5’11, and I was 134 lbs. But after covid, I lost 13 lbs, and now i’m 121 lbs. I was literally underweight all my life. I’m 28 now. It’s extremely hard to gain. I barely managed to reach 134 lbs with hard work. And now covid got me down broken. I’m so depressed and devastated.