What BMI doesn't tell you about your health



these are my assistants Coleman and Phil they're both around the same height weight and consequently they have the same body mass index or BMI but if you split them open damien hirst style or just compare the results of their body scan so you can see a slight difference phil has more body fat than Coleman and Coleman there's more muscle than Phil although BMI is a popular measure to assess if a person's weight might be putting them at risk for obesity related diseases its results can be pretty misleading and less nuanced then we light so the BMI is an index that looks at somebody's body weight divided by their height so formula is the body weight in kilograms divided by the height in square meters 18.5 and below is under way eighteen point five to twenty four point nine is your healthy range twenty five to twenty nine point nine is overweight and a BMI over 30 is classified as obese with the idea being that the taller somebody is the more they should weigh kind of weird how a single decimal point can separate being overweight from being obese the major problem with using BMI as a marker of Health when it comes to body weight because it penalizes you if you have a lot of muscle and you're healthier let's use professional athlete Marshawn Lynch as an example he's 511 215 pounds and his BMI is thirty he'd be categorized as obese that's because BMI doesn't distinguish muscle from fat we here we're really concentrating on how much muscle does somebody have because muscle it's the metabolic engine it's the thing that burns calories and the more muscle you have the easier it is for you to stay at a lower more healthy body fat percentage not necessarily a BMI in this way BMI is reliability as an indicator of health breaks down for athletes like Lynch there are several more variables that can influence the interpretation of things like age gender and ethnicity while BMI is a useful measure for a large population study for example to compare a relative obesity rates from state to state it becomes more problematic when you use it to determine an individual's health the body mass index was introduced in the early 19th century this guy who grade the formula I am so sorry I'm going to butcher his name lumber adolfo Jack Utley who wasn't even a physician was a Belgian mathematician his reason for crema formula was to study the normal man not obesity if you shifted to study obesity because of an selkies in 1972 keys use the formula in his indices a relative weight and obesity study renamed the formula to body mass index and from there the new measure caught on among researchers over the years it's using the health professional field group and it's pretty much stuck around since it's easy to use cheap fast and it's right about 80% of the time so even though BMI has stuck around for more than 200 years it's not the be-all and end-all health indicator there are more effective ways to assess body composition and overall health hydrostatic weighing or underwater weighing is an option along with MRIs ends and using waist-to-hip ratio medical tests like checking blood pressure glucose levels resting metabolic rate can further give a clearer picture of overall health I went to George Washington University and lab director Todd Miller showed me another way using dual energy x-ray absorptiometry or DEXA image it measures total body composition including fat mass lean body mass and bone density so the green is the areas where the body is very lean the yellow are areas of moderate fat and the red are areas of high fat but this person was here July 3rd she had 72 pounds of fat and 109 pounds of muscle and in December 27th of this year she had 37 pounds of fat in 115 pounds of muscle using this chart you can see if this person stepped on a scale they'd only see they lost 29 pounds what the scale wouldn't say is that they gained six pounds of muscle and BMI we didn't say that either so even if two people have similar BMI that one number will never truly give either of them the full picture of their overall well-being BMI is an indirect measurement of one aspect of an individual's health so while it can be helpful it shouldn't be the only way to understand the human body

36 Comments

  1. Read on Vox.com: "Being an overweight teen could come back to haunt your health" http://bit.ly/2FAhMmG

  2. Who thinks that BMI is the ultimate indicator of good health? Like, who actually thinks it's 100% accurate? Nobody that has common sense. Of course it's not giving you your muscle composition. However, if you are 100 pounds overweight and look like you can't walk, then yeah, I would think the BMI is pretty accurate when it's says you're morbidly obese. Let's not sugar coat it here.

  3. So, one BMI calculator I was on said I was supposed to be 78 lbs. I am 12, 5'4, and 113 lbs. Annaoop-

  4. Me(underweight):I have a regular workout (Calisthenics),I don't drink or eat alot of sweets,I always eat 2 banana's everyday.

    My classmate(Normal BMI):Who always drink soft drinks,who doesn't have a regular workout,and doesn't have proper diet

    Now who's healthier?

  5. I am a living stick (*゚ー゚)v

  6. Did anyone laugh when he said penalize

  7. I wanna see Dwayne the rock Johnson’s BMI

  8. 5’4 117 pounds?

  9. hogwash to make obese women continue to ignore their laziness

  10. All through elementary school my bmi was 0.04. But im just fine though. Idk what's wrong with me, ive just always been that way. I eat fine (probably more then I should😅) rn I'm 15 and weigh 84lbs

  11. Obviously doctors wouldn't have a professional athlete with a lot of muscle lose weight because BMI says they're "obese" like a lot of the things they suggest are super expensive like dexa and most places dont have that

  12. Mine is 23.47

  13. Don’t let the body positive movement see this.
    They’ll blow it out of proportion. Just like they did with their bodies.

  14. I’m 5”4 and weight less than 90 pounds. I’m just naturally used to not eating too much as I was a picky eater as a kid so I just wouldn’t eat what my parents served.

  15. My body mass is 40 but I’m extremely skinny

  16. BMI is for normal people not for the bodybuilders because. bodybuilders will have above 100kg of weight

  17. BMI is for normal people not for the bodybuilders because. bodybuilders will have above 100kg of weight

  18. Prime Mike Tyson at 5’10/220 is classified as obese by BMI. It’s a ridiculous calculation, especially for muscular men.

  19. 0:18 Way to expose Phil

  20. You can't measure height in square metres. You can square metres though.

  21. I have a bmi of 18.7 and still feel fat.
    Am i anorexic or is just the bmi wrong?
    Send help in the comments
    I am in despair

  22. stop dissing phil 🙁

  23. Anyone else has the sudden urge to workout?

  24. BMI doesn't care about your muscle content. Neither does weight but at least most people know that. BMI sounds scientific when it's another scam for doctors to put you on medications you don't need. A very good (and low tech) way to measure overall health is resting pulse. Again, this won't work by itself as an indicator but it's a lot better than the other two I mentioned.

  25. When in doubt just measure your body fat instead, the mirror helps too and your size in jeans.

  26. No one with a high BMI and a crap ton of muscles is looking at the BMI to see if they're unhealthy. If your doctor brings up your high BMI, you're fat

  27. So BMI just shows you if you are under or overweight compared to the average person your size

  28. Don’t use outliers to make your point.

  29. I'm 5'9" and 170 lbs, which technically makes me "overweight" but I know I'm not, especially since I'm very pear-shaped, it all goes to my thighs. I've been at this weight since high school and I'm 25 now.

  30. WTF
    I’m 13 and I’m about 4 feet 5 inches tall and I weigh like 85 pounds and my BMI is about 28 like what

  31. Bmi also doesn't look at where your fat is. Subcutaneous fat is usually fine but organ fat it dangerous.

  32. 2:00

  33. 1:35 If he was an inch taller his BMI would be “overweight” instead of “obese” lol

  34. This video is just for fat people to feel better about themselves

  35. Hey can someone tell me that is having a bmi of 23 considered normal?

  36. Bruh I got 20 and it said I was overweight

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