Spinach

One of Eat This, Not That's 8 Foods You Should Eat Everyday. It may be green and leafy, but spinach is no nutritional wallflower. This noted muscle builder is a rich source of plant-based omega-3s and folate, which help reduce the risk of heart disease, stroke, and osteoporosis. Folate also increases blood flow to the nether regions, helping to protect you against age-related sexual issues. Spinach is packed with lutein, a compound that fights macular degeneration. Aim for 1 cup fresh spinach of 1/2 cup cooked per day.

Substitutes: Kale, Bok Choy, Romaine Lettuce
Fit it in: Make your salads with spinach, add it to scrambled eggs, over pizza, mix with marinara sauce and then microwave for an instant dip.

Source: Eat This, Not That