How exactly do BMIs work, practically?
I'm 172 centimeters, 5"7 I think. According to the Australian Heart Foundation's BMI calculator, at 118 pounds I would be healthy at 18.7, but at 117 I would be underweight at 18.3. Why would losing one pound take away .4 from the total number? I'm 123 currently and don't look anywhere near underweight physically, although…