salad will fill you up without adding many calories. Also, you could use protein shakes as a snack.

I'd agree that protein shakes make great snacks and if you add a little peanut butter, that'll give you a little more fat and will seem more satisfying. Hard boiled eggs are also great snacks. You might even want to pick up a couple of protein bars, usually a couple of bites will satisfy you if you have a sweet tooth.

some nuts are good, or vegetables.
I usually like protein bars but they don't have not enought protein for me.
Protein shakes are the best. Mix with water and u got a very low calories and the protein u need.

1 word... Fiber

Beef Jerkey