Heredity is a bitch, and so is getting older. There are lots of guys who are thin and good-looking when they're younger, then once they get past 30 or 35 years old, they inflate like a freakin' balloon. Orson Wells, Raymond Burr, William Shatner... the list goes on. Okay, Shatner's not quite there yet, but he's losing the battle even as we speak. You can see the hugeness trying to take over.
Happens to ladies, too. Linda Ronstadt, Ann Wilson, Stevie Nicks. Absolute goddesses when they were younger. Now... still very pretty, but let's be honest, that extra 100 pounds almost makes me cry sometimes.