More surprisingly, the average waistline for American men and women are 39 and 37 inches respectively. That's the average! That means for every guy that's got a 30" waist, there's a guy out there with a 48" waist - crazy!
I'm not sure why in the Japanese system women are allowed to be wider? Considering that women on the average tend to be shorter, 35.5 for women seems unusual.
On a semi-related note, healthy people actually end up costing health-care systems more than the obese or smokers. Amusingly, this is because the smokers and the obese die before the healthy.