We Asked 2 RDs How to Choose a Protein Powder — Here's What They Said to Always Look For

First off, you should know why you're buying protein powder, Nikki Jupe, MS, RD, LD, a senior sports dietitian at The University of Oregon told POPSUGAR. For example, are you buying it for recovery after a hard workout, for weight loss, or for weight gain? You should also know the types of proteins offered, Nikki said. A few of the most popular types are: whey (animal-based), casein (animal-based), amino acids (essential amino acids are found in foods and supplements and nonessential amino acids are made by the body) such as leucine/L-Leucine, soy protein (plant-based), and pea protein (plant-based).

"The ingredient list should be as short as possible," Jason Machowsky RD, CSSD, CSCS, a board-certified dietitian and exercise physiologist at the Hospital For Special Surgery's Tisch Sports Performance Center told POPSUGAR. How short? "No more than two or three ingredients," he said. "Keep it simple. It's really one of best things you can do," he added.

Essentially, you just want the protein — forget all the other "benefits" being marketed. You'll more than likely find powders with stabilizing agents in them and flavoring. A stabilizing agent may sound like an FBI position, but it's typically included in powders because it prevents them from caking, Jason explained. Jason recommends avoiding sweeteners in powders and instead getting the sweet taste from natural sources like fruits. Here are some great high-protein fruit smoothie recipes.

Because supplements are not currently regulated by the US Food and Drug Administration, Nikki said to be weary of brands that promote and promise health claims. Currently, "Companies and/or manufactures can put any additives or ingredients in the supplement, and you do not know," she said. To circumvent consuming random ingredients, Nikki recommends only purchasing protein powders that have been third-party tested.

"Third-party tested means the supplement company pays for a third party to test their supplements and manufacturers for any ingredients not listed on the supplement label," she said. Nikki also recommends looking for containers that have a "NSF Certified for Sport" or an "Informed for Sport" label to identify clean protein powders.

The ingredients should be simple, but what about the type of powder? "Whey protein is the most researched and proven source of protein for muscle protein synthesis (the building of muscle mass)," Nikki explained. "However, there is no difference in choosing whey vs. soy [protein]. As a sport dietitian, I would recommend whey protein first unless the athlete (or individual) is lactose intolerant, vegetarian, or vegan. Then, I would recommend soy or pea proteins," she said.

"We tend to favor whey protein as the most rapidly broken down and absorbed type," Jason said. This means that it gets digested and absorbed into your body and muscles faster than other types of protein, he explained. Regardless of the type of protein you choose, Jason recommends keeping the ingredients list basic.

Although whey may be the preferred choice of protein powder, both dietitians agree that the best source of protein come from food such as chocolate milk, yogurt, lean meats, legumes, and beans.

Once you've selected your protein powder, you'll need to know how much to have. Most brands give basic instructions on how much protein to consume in one sitting, but if you're looking for something more accurate, follow Jason's recommendations. "Generally, you want to have 0.3 to 0.4 grams of protein per kilogram of bodyweight per given sitting," Jason said. According to Jason, this could be about 15 to 20 grams for someone who identifies as a woman and upward to 30 grams for someone who identifies as a man. To find out the optimal amount of protein you should consume, we recommend consulting a registered dietitian.

A common misconception is that you need to consume as much protein as possible to increase your muscle mass, which isn't necessarily true, according to Jason. "I tell people, 'You want to have enough protein to stimulate muscle protein synthesis, but more isn't necessarily better. Adequate protein in the presence of adequate calories or fuel is really what's going to stimulate muscle protein growth,'" he explained.

Buying protein powder shouldn't be complicated. Look for a short ingredient list, check for verified labels, and opt for whey if your goal is to build muscle unless you have dietary restrictions.

At the end of the day, we always recommend speaking to an expert such as a registered dietitian to help you make any nutritional changes.