Five food combos to power up your diet

Like Dwyane and LeBron, some foods just work better when they're together. "Combining certain nutrients, fats and compounds can help your body better absorb and use these vitamins and minerals more effectively," said Marisa Moore, R.D., an Atlanta-based spokesperson for the American Dietetic Association. "They work synergistically, so you get the most bang for the buck." Try pairing these foods for a nutritional slam dunk.

1. Red peppers and spinach

"Your body needs the vitamin C in red peppers to process the iron in spinach," Moore explained. This mineral ferries oxygen to muscles, upping your energy levels and endurance. According to a Cornell University study, iron-deficient women who took an iron supplement during a six-week training program slashed nearly four minutes from their 15k bike trial times, while those who got a placebo shaved off a mere two minutes. Aim for 18 milligrams of iron daily from lean meats; dark, leafy greens; and beans. Serve it with a C source, like red pepper, spinach, tomatoes or citrus.

2. Avocado and salsa

Bring on the guacamole! Researchers from the Ohio State University found that people who added this green fruit to salsa absorbed five times more immune-boosting beta-carotene than those who didn't dress up their dish. "Certain antioxidants called carotenoids require fat to be digested," Moore said. Since tough workouts can deplete your body of these disease-fighting nutrients, add a quarter-cup, or a few slices, of avocado to your tacos, salads and sandwiches.

3. Whole grains and garlic or onions

Mixing sauteed garlic and onions into your whole-wheat pasta or rice dishes can do more than pump up the flavor -- it also can boost their nutrient profile. The sulfuric compounds in these spices appear to make the whole grains' iron and zinc more accessible to the body, reports a 2010 study in the Journal of Agricultural and Food Chemistry. "Both of these minerals play an important role in immune function," said Moore. "They can help fend off sniffles." Spice up your health by stirring garlic or onions into a rice pilaf or spaghetti sauce.

4. Olive oil and vegetables

Fat-free dressing is so 1999. Plus, topping your salad with the globs of the stuff means depriving yourself of vision-protecting antioxidants like lutein and zeaxanthin, reveals a study from Iowa State University. These (and other) carotenoids are fat soluble. To pull every last free-radical fighter from your veggies, add at least 6 grams of fat -- the amount in about half a tablespoon of olive oil -- to your salads and vegetable dishes.

5. Oatmeal and strawberries

Instead of scooping on sugar, sweeten your morning bowl of oats with fresh strawberries. Just eight juicy berries deliver all the vitamin C you need in a day, and a 2004 study in the Journal of Nutrition suggests that the nutrient can also enhance the action of oatmeal's phenols. These plant compounds stabilize LDL, or "bad," cholesterol in the bloodstream, which prevents them from building up in arteries and paving the way for heart disease. The berries appear to boost the cholesterol-fighting punch by blocking the actions of free radicals, which can damage cholesterol and make it more likely to stick to your arteries. Out of strawberries? Wash down your cereal with a glass of OJ to score the same benefits.