One of my 2 cats is a rather large girl.  As a kitten, she seemed to have a very long tail, proportionally, for her body size.  It took a couple of years to fill out, but she grew into her tail!  My friends swear I'm raising a small tiger.  Given that her trail now looks proportional to the rest of her, I believe she was destined from birth genetics to be a large cat.

Still, I didn't want her to be fat.  Being too large can cause other health problems for cats, just as it does for humans.  I tried Science Diet Light in hopes of reducing her weight.  Unfortunately, she just seemed to eat...