So weight = density * volume = a constant (assuming constant density) * height * width * other width
BMI = weight/height^2 = density * width * other width/height
Unless you are a freak of nature, your, um, width and other width = < your height. So...taller people should actually have lower BMIs in general, correct?
The problem with your math, I think, is that our volume is not height cubed...that would assume that we're spheres. If anything, we're more like cylinders (i.e. h*r^2), although this isn't entirely accurate, either...
Still, I rather like BMI as a rough approximation. If your BMI is 22, you're pretty normal. If it's 40, you probably either are quite plump or are a crazy body builder. It's hardly perfect, but it's better than "if you are 120 lbs as a female, you are over weight", without acknowledging that a very tall woman is bound to be heavier than that.
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timeasmymeasure
no subject
Date: 2011-04-06 04:02 am (UTC)BMI = weight/height^2 = density * width * other width/height
Unless you are a freak of nature, your, um, width and other width = < your height. So...taller people should actually have lower BMIs in general, correct?
The problem with your math, I think, is that our volume is not height cubed...that would assume that we're spheres. If anything, we're more like cylinders (i.e. h*r^2), although this isn't entirely accurate, either...
Still, I rather like BMI as a rough approximation. If your BMI is 22, you're pretty normal. If it's 40, you probably either are quite plump or are a crazy body builder. It's hardly perfect, but it's better than "if you are 120 lbs as a female, you are over weight", without acknowledging that a very tall woman is bound to be heavier than that.