Popcorn
Compared to many other popular snacks, popcorn is a whole grain that contains a lot of fiber. This whole grain snack is also high in volume, filling the space in your stomach quickly. Studies have found that popcorn will fill you up more than other popular snacks such as potato chips. Air-popped popcorn is the healthiest. Commercially prepared or microwave popcorn can be extremely high in calories and contain unhealthy ingredients.