Same. I played very little of San Andreas and didn't play GTA 4 at all, though I've watched roomates at college play a bit. The thing that annoyed me with San Andreas was constantly having run back and forth between the burger shack and the gym so that my character could function like a normal human being.
Eventually I got so annoyed with it I just f**k it, I'll take 74 whoppers, 218 orders of large fries, and Diet Coke to go along with it (no need for them pesky excess calories, right?)
Dude looked like a mammoth lol. I figured the weight would natrually work itself off by playing and starving him in the process, and even though I ran at a speed of about 25 feet an hour I wouldn't have to worry about him keeling over from weighing 40 lbs every other minute.