BMI

Speaking of BMI, I'm sure you've all heard about the inaccuracy of this measurement. If not, you can read about it here. Essentially, the Mayo Clinic in Rochester, MN compiled a bunch of data and found that people with a lower BMI were more likely to suffer from heart disease than those with a normal BMI, and "obese" people were less likely. As the article points out,

This apparently perverse result, drawn from data from 40 studies covering 250,000 people with heart disease, did not suggest that obesity was not a health threat but rather that the 100-year-old BMI test was too blunt an instrument to be trusted.

So don't stress about your BMI. And check out this amazing flicker slideshow, displaying pictures of various people and their BMI rating. For example, the following women are "overweight."