Lettuce

 Lettuce is a filling, nutrient rich veggie entirely free of fats and sugars. Lettuce is a great source of dietary fiber, calcium, potassium, and vitamins C (a powerful antioxidant that aids immunity), A (which is essential for healthy skin and vision), and K (which promotes bone mass). All lettuce have different qualities (Napa cabbage is crunchier than green leaf, etc.), but always choose lettuce with healthy, vivid leaves and avoid lettuce with limp leaves or discolored spots. Thoroughly wash your lettuce before eating it, as produce with an outer skin or peel can absorb and retain harmful pesticides.

Image: Lettuce, Rebecca Partington, Creative Commons.