Would a jacked 200 pound guy be less likely to die than a fat 200 pound guy at the same height?
It’s true that BMI is flawed (particularly in the case of athletes, weight lifters, and the elderly). However, it is the MOST COMMON weight assessment used in studies assessing health. As well as in clinical practice.
To use an analogy… even if your yardstick is flawed, you will still acquire meaningful results to review when measuring with a flawed yardstick if that’s all you got. It just won’t be accurate for all populations.
Body composition is a better means to determine someone’s LBM and total fat mass. However, this cannot be performed at home like a simple BMI calculation can.
Both have pros and cons.
But to answer your original question, the man weighing 200 lbs of mostly fat will be unhealthier. Fat stores toxins/pollutants. Then you factor the lifestyle that got them there.
Overall inflammation is a better indicator of health than either of those. Many muscular people are considered obese per the BMI. There are so many lifestyle factors that go into health, trying to find similar markers of health in two different people with different lifestyles isn’t a good idea for the sake of data collection.
Between the two, I would say body fat percentage. BMI takes into account ONLY weight and height in its calculation while excluding other factors such as muscle composition. On top of that, it is skewed heavily by height due to height being squared in the denominator. This means that BMI is overestimated for people shorter than average and underestimated for people taller than average.
My BMI is 28 which classes me as overweight, on the way to obese. Like hell I am!
If I say it myself, I’m in pretty damn good shape. I can out-row, out-run, out-lift most guys half my age. My doctor is blown away by my slow, strong RHR and my body fat is 18-19%
BMI is ok as a broad measure of statistical population health, but IMHO its near useless for individuals.
BMI is a flawed indicator. Doesn’t take into account muscle, body frame, ethnicity. It’s also flawed for underweight people. Some people have thin frames. Some have bigger body frames. There are many things to factor in. (I work in nutrition).
BMI is a mostly useless number that tells you very little.
Body fat percentage is an excellent indicator of body composition, but is not hugely indicative by itself of overall health.
It’s a combination of several measurements that determine health.