How many protein shakes a day should you drink? We asked the experts.

Few wellness and supplemental products are as popular as protein shakes. Already a $6 billion industry, it's expected to grow even more at a rate of nearly 10% annually. Actor Chris Hemsworth swears by them, fitness influencers promote them, and tennis legend Venus Williams has started her own protein shake company to get a piece of the action.

But experts say protein shakes aren't for everyone and aren't even needed as part of a balanced diet. Still, the beverages do offer some health advantages under the right circumstances. "Protein shakes can help athletes and non-athletes meet their overall protein intake, but there are a couple things to know before purchasing them," says Ashley Hagensick, MEd, RD, a sports dietitian at Intermountain Health.

What are protein shakes?

Protein shakes are beverages in which protein powder has been added. They are popularly mixed up in shaker bottles pre or post workout or may be formulated in pre-packaged cans or bottles. Either way, the beverages are intended to build muscle, provide energy, and may even improve recovery time after a workout. "Protein shakes can be a good addition to one’s intake if used for the right purpose," says Nikki Cota, MS, RDN, an outpatient clinical dietician for Mayo Clinic.

Amounts of protein in ready-made protein shakes vary from manufacturer to manufacturer. Some have as little as 10 grams, while others offer as much as 25 grams of added protein within only 14 ounces of liquid. Many protein shake brands also include fiber, vitamins, minerals and sometimes less desirable ingredients. "Many shakes and powders have additives like sugars, artificial flavorings and colorings," says Brooke Levine, RD, dietician nutritionist at NYU Langone Health. "So, make sure you choose a shake that aligns with your health views and needs." Sweeteners are especially important to look out for as some brands add as much as 30 grams in a single protein shake. The American Heart Association recommends limiting total daily added sugar intake to 25 grams per day for women and 36 grams for men.

Are protein shakes good for you?

Protein shakes offer many of the same health benefits as other sources of protein. "Protein consumption helps with building and repairing muscle and other tissues in the body," explains Cota.

Protein shakes can also help with weight management as they "increase satiety − a sense of fullness, without a significant increase in caloric value," says Fatima Cody Stanford, MD, director of diversity at The Nutrition Obesity Research Center at Harvard Medical School.

While most people can get all benefits of protein from a balanced diet alone, some people need supplemental protein as well. For example, vegetarians are commonly protein-deficient and anyone looking to increase muscle mass may consider increasing their protein intake.

How many protein shakes a day should you drink?

The Dietary Guidelines for Americans recommends for women and girls ages 14 and up to get 46 grams of protein per day and for men ages 19 and older to get 56 grams of protein a day.

Stanford suggests that "people should still aim to get protein from food sources," but adds that supplemental protein may be helpful in some cases. "Protein shakes are not meant to replace a meal but should be used as a supplement to what one is consuming from whole foods," echoes Cota. Food sources that are high in protein include eggs, shellfish, nuts like almonds and peanuts, chicken breast, lean beef, milk, Greek yogurt, and turkey breast.

And while protein needs vary from person to person, "I would not suggest consuming more than one protein shake in a day to allow for other macro and micronutrients into the diet," recommends Hagensick.

More info here: You know protein builds muscle, but how much should you eat?

It's also important to note that when it comes to protein shakes, the FDA "leaves it up to manufacturers to determine the safety and labeling of products," says Levine, "so use your judgment." To help with this, Hagensick advises to check the labels of one's protein shake to make sure that it has been "3rd party tested by either NSF or Informed Choice to make sure the product actually contains what it says it does." She also recommends spreading protein consumption out throughout one's day and not all in one sitting.

How much protein per day is safe?

What's more, drinking too many protein shakes can cause negative side effects. "You may experience digestive issues like upset stomach, bloating and gas if you consume large amounts of protein shakes and powder," cautions Levine. "Please consult with your registered dietitian to find the best fit for you."

This article originally appeared on USA TODAY: How many protein shakes a day should you drink? Experts talk safety.