Protein powder pros and cons: What to know, what to watch out for

By Katherine Dillinger, CNN

Updated 1452 GMT (2252 HKT) March 9, 2018

Chat with us in Facebook Messenger. Find out what's happening in the world as it unfolds.

A new study suggests that eating plant protein can lower your risk of death, while eating meat is associated with an increased risk of death. Soy serves as a source of protein, such as in the form of tofu.

Photos: 6 sources of plant-based protein

Soy – A new study suggests that eating plant protein can lower your risk of death, while eating meat is associated with an increased risk of death. Soy serves as a source of protein, such as in the form of tofu.

Hide Caption

1 of 6

Photos: 6 sources of plant-based protein

Whole grains – Whole grains include plant-based proteins.

Hide Caption

2 of 6

Photos: 6 sources of plant-based protein

Nuts and nut butter – Nuts and nut butters, such as peanut butter or almond butter, contain plant protein.

Hide Caption

3 of 6

Photos: 6 sources of plant-based protein

Leafy greens – Leafy greens are also a good source of plant protein.

Hide Caption

4 of 6

Photos: 6 sources of plant-based protein

Quinoa – People trying to cut back on meat might try quinoa as a source of plant-based protein.

Hide Caption

5 of 6

Photos: 6 sources of plant-based protein

Brown rice – Brown rice can pack a punch of protein.

Hide Caption

6 of 6

Story highlights

Convenience is the top benefit protein powders offer, especially for athletes
Too much protein -- starting at about 35% of daily calories -- can lead to health issues

(CNN)Protein powders are expected to be a $7.5 billion industry by 2020, and the products are popular for a wide variety of reasons: Vegetarians might feel that their diets are somewhat lacking, athletes may want to add muscle faster or aim for a competitive edge, and still others might be looking for a quick meal that isn't dripping with grease.

And there's an equally wide variety of products on the market. Here's what you should know about protein powders.

Protein is an important building block for muscle as well as hair, skin and nails. Powders are dehydrated forms from sources such as milk, soy or plants. They're typically mixed with water or other beverages, or they can be added to foods to boost protein content.

Athletes' protein needs can be up to twice those of the average person because of the energy they expend and the process of breaking down, repairing and building muscle. Many vegans also use protein powders in lieu of animal-based sources such as meat, dairy or eggs.

Are energy bars healthy?

The recommended dietary allowance for protein is about 0.8 grams per kilogram of body weight each day, which translates to 54 grams for a 150-pound person.

However, "I think those estimates are a little conservative," nutritionist and health journalist