Not sure about this. The other side of the U shaped curve (and it is a U shaped curve) has not been well studied. From what I gather a BMI in the early twenties up to around 25 has no significant increased morbidity risk. It goes up really fast when you are above 30 though.
People with BMIs under 20 have significant morbidity risks too. Although it seems like a low BMI (18-20 range) is okay provided you arn't malnurished, have some kind of eating disorder, or are quite old. My BMI is, I think, around 19 but I put that down to large amounts of long distance running which tends to do that to you after a while.
Upshot is, you shouldn't be worried if you have a BMI in the 23-26 range unless you have any metabolic risk factors (such as high blood pressure, high blood sugar, high levels of visceral abdominal fat e.c.t.).
And if you do have those metabolic risk factors they are a problem regardless of your BMI.
Originally Posted by: Quantum