Low-fat milk, powdered milk and low-fat cheeses (cottage cheese being at the top of the list) are huge protein producers. An added bonus? They're all natural.
"I'm a fan of real foods. Most bodybuilders can get the protein that they need through their diet. But if they want a protein shake, they can certainly spend their money on it," says Clark. "They can also take skim milk and powdered milk and a banana and blend it all together, and make a protein shake that way."
While Clark isn't opposed to supplements such as casein and whey, she says much of their purported benefit is more marketing hype than reality. Current research, she says, indicates that "milk, which has both casein and whey, has a synergistic effect, in that it enhances muscle building more than an isolated nutrient."
"A lot of (body builders) like whey protein, and they tend to gravitate toward that. And it's a source of protein," she says. "But I think, in the long run, whole foods have a synergistic effect that really enhances not only health, but also muscle development."