Now that high-protein diets like the Paleo Diet are trendy, it only makes sense that we'd see other food and beverage products marketed as high-protein. Case in point: the rise of "protein water," or bottled water that claims to be enhanced with protein.

But is protein water actually good for you? And for that matter, does it actually contain that much protein? We asked an expert for his take.

What, exactly, is in protein water?

“Protein water is infused with whey protein isolate, which helps to contribute to growth and maintaining lean muscle mass,” says Jim White RDN, ACSM, owner of Jim White Fitness and Nutrition Studios.

Typically, a 16-oz. bottle of protein water will contain between 60 and 90 calories and 15 and 20 grams of protein.

Is protein water good for you?

The good news is that protein water usually contains fewer calories and less sugar than, say, protein shakes. “Many guys use this to help with recovery immediately after exercise," says White. "Consuming some form of protein post-workout can help to rebuild any damaged muscle tissue that occurred during the workout, so if this is all you can grab, go for it."

That said, you’re much better off eating real food after a workout. “The protein contained in these waters is not a complete protein, meaning it does not contain all of the 9 essential amino acids,” White explains. “Getting protein from real food, like meats or beans, will allow for a more satisfying experience and keep a person full for a longer period of time.”

To build muscle throughout the day, you should aim for a daily protein intake of about 1.2-2.0 g per kg of target body weight, he says. So chugging a 16-oz. bottle of protein water after your workout isn't really gonna do much.

Additionally, while protein water typically contains less sugar than most protein shakes, it does contain small amounts of artificial sweetener like sucralose or stevia, which have been linked to increased sugar cravings. You should also stay away from protein water if you're lactose-intolerant, as whey isolate contains dairy.

The bottom line

A bottle of protein water isn’t gonna hurt you, but you still probably shouldn't chug it every day. Even though it may be lower calorie than a shake or a protein bar, it’s still not totally sugar-free or calorie-free like good ol’ H20.

At the end of the day, "protein water does not provide the recommended amount of protein and carbohydrates needed for exercise recovery, or even to sustain a person for a long period of time,” White says. So if you really want to try it, combine it with another protein-rich snack, like yogurt and cheese and crackers.