Whey is considered a superfood by doctors and fitness fanatics alike. And for good reason.

High in protein, whey is believed to be the most thermogenic food on the planet. It is also a great way to boost your body's production of glutathione - a natural detoxifier and anti-aging substance.

Whey is the liquid remaining after milk has been curdled and strained; it is a by-product of the manufacture of cheese or casein. Whey proteins primarily consist of a-lactalbumin and ß-lactoglobulin. Depending on the method of manufacture, whey may also contain glycomacropeptides (GMP).

Beware of whey proteins sold in "health food" stores as they often contain artificial sweeetners and are made with cows treated with rBGH.