Sweetdaisy suggested low fat popcorn, which is one thing we do for snacking.
ACT II Mini Bags 94% Fat Free Butter popcorn (I buy it cheap at Wal-Mart) has 100 calories per popped bag and makes several cups of popcorn. 1.5g total fat, 0 g sat fat, 0 g trans fat, 0 mg chol, 150 mg sodium, 21 g carb, 2 g dietary fiber, 3 g protein and 4% iron.