Lap band/gastric byp?

These methods seem to be the way to lose weight these days, but I'm not convinced that altering your body surgically is the way to go- my friend just got a lap band put on and she still eats crap- we went out for llunch and she got a fried seafood plate with fries and a soda. Can this hurt her? She's not loosing the weight fast enough (wonder why) so she's thinking of going to the byp. Has anyone had this done? How safe is it really?