peanuts are way to high in calories, unless thats what youre looking for. peanuts were my secret weapon for eating 5500kcal a day. i gained 30lbs in 2 monthes that way but got pretty fat too.
low calorie snacks are mixed raw vegies. cauliflower, broccoli, carrots, mushrooms, cucumbers. eat em plain or with a little fat free ranch. apples are good too and satisfying. my girlfriend snacks on ice cubes. wierd but its the ultimate low cal snack, it actually burns calories!
good luck bro and remember that no one ever got fat from eating too many carrots!