10 Healthy Foods That Cost Under $1

Popcorn ($3.49 per 9-ounce box or $0.39 per 1-ounce serving)

While butter-soaked movie-theater popcorn has a bad reputation, plain air-popped popcorn is a great whole-grain snack that adds up to only 30 calories per cup. Whole-grain foods contain the entire grain kernel, which means that they have more nutrients than refined grains and can help reduce the risk of stroke and diabetes. For a tasty snack, Stadler suggests topping plain popcorn with “a teaspoon of olive oil for heart-healthy monounsaturated fat and a couple of tablespoons of nutritional yeast to add flavor and vitamin B12.”