The moment it enters your mouth, protein starts winnowing your waistline. High-protein foods take more work to digest, metabolize, and use, which means you burn more calories processing them. They also take longer to leave your stomach, so you feel full sooner and for a longer amount of time. The cumulative effect has obvious benefits for anyone who is watching her weight.

Protein is doubly essential for making sure you lose fat, not muscle. Your body uses the amino acids in protein to build lean muscle, which not only makes you stronger and more toned but also fries calories even when you're not active—unlike lazy fat. Ultimately, this keeps your metabolism humming along at high speed so you can burn off the occasional ice cream or barfi, no problem.

While nuts, whole grains, and veggies technically count, they don't contain all nine of the amino acids your body needs in order to build lean muscle. Those that do—known as complete proteins— are typically found in animal products. Your best flat-belly bets are skinless white chicken or turkey, seafood, low-fat dairy, pork tenderloin, and lean beef.

Vegetarians need to be a little more creative. Pairing incomplete proteins—peanut butter on wholewheat bread, or brown rice and beans, all pulses and sprouts. Even milk products like curd, tofu, paneer, cheese, etc, have an abundance of protein. Here's one example, though a quick Internet search will uncover hundreds of delicious protein shakes:

• 8 oz skim milk

• 1 banana

• 1 tbsp peanut butter

• 2 scoops of protein powder

The beauty of protein is that with so many tasty options, getting your daily dose is a simple pleasure.

- Radha Krishnaveni