Antioxidants. We know they're good for us and that we need to eat lots of them, but what exactly are they?

Antioxidants are nutrients found in food like beta carotene, certain vitamins, and selenium, that can prevent damage and help repair your body cells. They work by drastically slowing down the damage caused by harmful free radicals resulting from oxygen. Antioxidants also boost your immune system and can help to fight against infection and cancer.

When searching for antioxidant-rich foods, it's important to find foods that are high on the ORAC (oxygen radical absorbance capacity) scale. A new diet book called "The O2 Diet" by Keri Glassman, R.D. said that counting antioxidants is a better way to lose weight than to count calories.

In short, a diet brimming with fruits and veggies, whole grains and nuts is a one-way ticket to antioxidant-land and overall good health. Add these five delicious eats to your daily diet and ensure you're getting your daily fill of antioxidants:

1. Grapefruit: Every since the rage of the grapefruit diet back in the 90s, grapefruits have been celebrated as metabolism boosters and weight loss helpers. It's not so surprising considering that they're armed with lycopene and fiber. Try starting your day with a grapefruit or eating half a grapefruit before each meal to curb your appetite and craving for a little sweet something.

2. Artichokes: Artichokes are low in calories, super delicious and high on the ORAC scale. They're known to help lower cholesterol too. Steam artichokes for a nutritious dinner side or cut 'em up and add them to a salad.

3. Lemon Water: We all know drinking more water is critical to better health. Adding a spritz of lemon and a chunk of lemon peel to your water can aid in weight loss and help you stay fuller longer. Plus, it's a great food-free way to cram in some extra ORAC points.

4. Dark Chocolate: Of all the 101 reasons to enjoy a piece (or two) of dark chocolate, the most compelling one is its high levels of antioxidants. Rich in flavonoids, chocolate, the darker the better, can help keep your heart health and keep you relaxed.

5. Leafy Greens: Specifically kale, chard, and spinach are antioxidant powerhouses. From starting the day with a spinach-enhanced fruit smoothie to ending it with kale chips instead of popcorn, get creative with adding leafy greens to your diet.