Waist size matters.  Frankly speaking, whether you have the apple shape, pear shape, or you have an hourglass shape, they measure obesity based on waist circumference and body fat percentage, not on pure weight.  This is because quite frankly, when you have more fat in the abdomen, it is surrounding the vital organs in general and therefore it can be more harmful and otherwise to your health than you would experience with other areas of fat in general.  This is why a lot of fitness tests base part of their analysis on waist size. 

It is meant to measure fitness and overall health and wellness.  So quite frankly, if you have a smaller waist, due to the health implications, you have a higher rate of healthy options.  Even if you have more fat in the lower areas of the body, you could still be considered more fit or otherwise healthy than somebody who had the same buildup in the stomach even though every other area was fine.  So next time you think that it shouldn’t be measured by waist size and it shouldn’t be determined on that basis, think again and look into it a little bit deeper.