Back in the day, the only people you found gulping down protein drinks were big, hulking body builders.

Now, according to one nutrition industry expert, more than 60% of consumers are enhancing their diets with protein drinks and powders.

"Hundreds of protein powders and drinks have flooded into health food stores and supermarkets, marketed as dieting aids, meal replacements, energy and endurance boosters, sports recovery aids, and easily-absorbable sources of protein," sports drink guru Anders Porter of Team Core Power told us.  

Porter says we are witnessing a global protein revolution. And with so many protein products to choose from, the expert cautions consumers to beware, because all protein drinks and powders are not 'created equal.'  

"Because neither the FDA nor any other government agency routinely tests protein powders and drinks to assure ingredient quality, it makes sense for consumers to arm themselves with enough information to be able to ask retailers and manufacturers some hard questions before spending their cash on protein drinks and powders," Porter warned.

According to Porter, there are five key questions that health-conscious consumers should be asking about any protein drink or powder before they shake it up, pop-the-cap or chug the contents. Check out the first below:

What is the source of the protein; Plant or animal?

Porter says animal proteins are more complete than plant proteins, as plant proteins are deficient in at least one nutritionally indispensable amino acid (IAA). "IAAs cannot be created by our body and must be provided through food. Milk as a protein source contains all the IAA's," he explained.

"As a source of protein, milk has a biological value of 91-93, followed by soy with a biological value of 74, and wheat with a biological value of 64. Milk protein has a digestibility of 94-95 percent, compared to 91 percent for soy, 86 percent for wheat and 88 percent for rice protein."

Look out for the rest of what you need to know before you chug a protein shake tomorrow.