Acorn squash is an easy to prepare, low-calorie, nutrient packed addition to any meal. Acorn squash provides vitamin B6, complex carbohydrates, potassium, magnesium, folate, thiamine and dietary fiber. When shopping for the right acorn squash, pick one that is that is heavy for its size with smooth, dull skin and no soft spots. A good balance between green and orange coloring is ideal. Fun fact: squash is considered a fruit, not a vegetable.