I think Ness is fat, since 1 of the cops says fat boy.
There is an NPC that comments that he lost weight at the end of the game. Also I think there is another NPC besides the cop that calls him fat as well. I picture him to be not as fat as Porky, but more like he's kinda on the husky side. A little overweight, but not obese.
>this thread
He’s fat.