To help ensure your lunch is giving you rock star energy -- instead of weighing you down -- you just have to follow three simple rules.

According to RealAge expert Mehmet Oz, MD, the three keys are quality carbs, healthy fat, and lean protein -- nutritional bases you need to cover to keep energy levels from bottoming out.

1. Quality carbs: Build your meal out of complex carbs -- the kind that are digested slowly to give you a longer, steadier stream of energy. Just about any high-fiber carb will do, including beans, brown rice, whole-grain bread, quinoa, and veggies like brussels sprouts and eggplant. Make this roasted-veggie tart from EatingWell on Sunday for all-week slice-and-go lunches.

2. Healthy fat: You'll need a bit of healthy fat to help your body absorb all the goodness of certain fat-soluble nutrients in your meal (like vitamins A, D, and E). Fats also help you feel full longer. Try topping soups and salads with chopped walnuts and drizzling some olive oil on your whole-wheat pasta. Sandwich lovers, replace your mayo with a few slices of creamy avocado. And try this slimming type of salad dressing.

3. Lean protein: Dr. Oz recommends making your meal "mostly veggie" and then adding some lean protein to give it a little more lasting power. Skinless chicken, lean meats, fish, tofu, eggs, and beans are all primo sources of healthful protein. Hit all three lunch essentials in one fell swoop with this EatingWell recipe that packs a lightly dressed, veggie- and protein-rich punch: Green Goddess Salad.

And get more daily-living health tips from Dr. Oz by tuning in to The Dr. Oz Show. Find your local listing!

Tips from the RealAge Community

Which lunch item gives you the most staying power?