Well, we (students) still don't have enough money to gain weight - but if you spend some time at home your whole family wants to feed you up, so you can certainly gain some weight during the holidays.
My roommate is constantly trying such strange things like diets - once he decided only to have breakfast and nothing to eat the whole day to save money. But he stopped that after a week when he got hallucinations and nose bleeding in the tube (no joke)!
Now I can tease him with eating Schnitzel while he's only having a lousy wholewheat bread.