It's as exactly as it sounds--a powdered form of protein!  Once primarily used by bodybuilding and athletes, protein powder has definitely made its way into the mainstream. It is considered to be a 'food supplement', meaning that protein powders are originally intended to add something to the diet that may be missing.  Protein supplements come in a variety of forms: ready to drink shakes, bars, bite-size pieces, gels and powders.

Protein powders have many uses.  The most common use is to mix the powder with water, milk or another liquid to make a 'shake'. Protein powders are often added to vegetable or fruit smoothies to create a more filling meal or post-exercise recovery snack. Protein powders can also be added to baked goods, oatmeal, cereal and soups to add additional protein in the diet.  

The Protein Digestibility Corrected Amino Acid Score(PDCAAS) is used to assess the quality of a protein based on its amino acid profile and how well it digests in humans.  A PDCAAS score of 1.0 is the highest, while a 0 is the lowest. A higher score means that food item has a better protein quality. Casein, whey, soy and egg whites all have a score of 1.0, whereas whole wheat has a score of 0.42 and peanuts a score of 0.52. 

Great question!  While it's difficult to apply a broad statement to each individual, in general, most people can consume enough protein from traditional food sources (meat, tofu, beans, cheese, milk, etc.) so that an additional source of protein isn't necessary.  Individuals such as cancer patients or burn victims are likely to have greater protein needs as their bodies are rapidly using up protein stores to repair muscle and tissue. But, protein powder is a very convenient way, especially in the morning, to get a serving of protein.  If a protein smoothie makes it easier for you to actually eat breakfast in the morning, go for it! Keep in mind, a protein shake isn't recommended as meal-replacement. On average, a scoop of protein powder has about 100 calories. Even if you're mixing it with 8oz of milk, that's only about 190-220 calories, hardly enough for a complete meal. Meal-replacement products should only be used as part of a medically-supervised weight management program & are not intended for lifelong use.  Protein is also needed as a post-workout recovery aid when you're doing high intensity and/or long term (60 minutes or greater) exercise, such as heavy weight lifting, moderate-intense lap swimming and running.   After this type of workout, you'll want to consume a bit of protein along with carbohydrates, but the form of protein (i.e. actual food vs. powder) doesn't really matter.

Choosing the right protein powder for your body's needs can be overwhelming as there are so many products available. Here are some differences between various types of protein powders:

Whey is the left over product when milk coagulates and is a by-product in the production of cheese. Cow's milk is 20% whey and 80% casein (a slow-digesting type of protein, usually found in cheese), compared to human breast milk which is 60% whey and 40% casein.  Whey protein contains about 5% lactose, minerals and lactalbumin, as well as the three branched-chain amino acids (BCAAs) leucine, isoleucien and valine, which are involved with muscle protein synthesis.  Whey protein is absorbed rapidly by the body to aid in recovery (post-exercise, trauma, etc.), thus making it an ideal supplement for those who have higher metabolic needs, such as burn victims, cancer patients or individuals recovering from bariatric surgery.

Whey protein powder is found in three forms--concentrate, isolate and hydrolysate:

• Concentrate:  29-89% protein by weight; less processed but has less protein; has some fats and carbohydrates (as lactose)
• Isolate:  90% protein by weight; processed so that fat & lactose are removed; more expensive than concentrate
• Hydrolysate:  more expensive, predigested and partially hydrolyzed (water is added to a substance, causing the substance to split into two parts ) so that the body can metabolize it easier; free of most allergens

Try:  Natural Factors 100% Whey Protein (unflavored); Unjury® Protein Powder

A great option for those with a milk allergy, egg white protein powder has a high PDCAAS score (1.0). It's very low in carbohydrates (<1.0 gram/serving), high in protein (~ 24 grams/serving), less than 1 gram of fat per serving and is a good source of potassium.  Keep in mind, many of egg white protein powders add some type of non-nutritive sweetener (such as Stevia) or use soy lecithin as a thickener, which may make it unsuitable for some people with a severe soy allergy.

Try: Jay Robb Vanilla Egg protein powder;  

Healthy & Fit 100% Egg protein powder (vanilla)

Soy protein is actually isolated from the soybean.  It's used to make soy flour, soy concentrate and soy isolates.  Soy flour is made by grinding soy beans into a fine powder and is often used in gluten-free baking. Soy concentrates are about 70% protein and are made by removing the carbohydrates from the dehulled, defatted soybeans. Soy isolates are highly refined and have a minimum of 90% protein. They are used to increase the amount of protein in a food, improve texture and help retain moisture.  Soy protein is suitable for those on a vegetarian or vegan diet.  Unlike most plant-based sources of protein, soy is a complete protein, meaning it contains all of the essential amino acids that our body needs but cannot make on our own.  Some studies have shown that soy may have positive cardiovascular benefits.

Try:  Bob's Red Mill soy protein powder;  GeniSoy soy protein powder

Made from hemp seeds, this protein powder is a great vegetarian and vegan source of protein as it contains all 9 essential amino acids.  Per 4TB (30 g) serving, it has roughly 630mg of Omega 3 fatty acids (~39% of the Recommended Daily Value!), 9 grams of fiber and 13 grams of protein. However, hemp tends to have lower amounts of protein compared to whey and soy. Some lines of hemp powder carry a "high protein" version, which can have anywhere from 15-22 grams of protein per 30 gram serving.  Most hemp protein powders contain about 37-50% protein, with about 10-12% fat and varying amounts of fiber and carbohydrates.  Hemp protein powder is also a good source of magnesium, iron and manganese.  Keep in mind, hemp contains 0% THC and is safe and legal to consume.

      Since hemp powder is higher in fat (albeit heart-healthy fat) compared to other types of protein powder, it may not be the best choice for post-exercise recovery.  After intense exercise, your body needs to rapidly reabsorb nutrients. Too much fat can slow your body's absorption of carbohydrates, protein and minerals.  However, if you're having hemp protein as part of a breakfast shake and you're not working out until the evening, the extra fat in hemp protein is a benefit.

Try:  Nutiva Hemp Protein powder; Trader Joe's Hemp Protein Powder; Living Harvest Tempt Organic Hemp Protein Powder

This is a good option for those looking to avoid dairy or soy-based protein powders. It is naturally gluten free and is suitable for vegetarians and vegans.  Rice is easily digestible, so those with gastrointestinal (GI) issues may tolerate this type of protein better than animal-protein powders.

Try:  Growing Naturals, Organic Brown Rice protein isolate powder

Many protein powders combine different types of protein (i.e. whey + soy protein).  Note that some protein powders may contain soy lecithin, which is used as a thickener/binding agent and is different from soy protein powder. Here are a few brands:

Natural Factors Vegan Protein Powder: contains a mixture of yellow pea protein, sprouted brown rice protein, hemp protein and chia protein

Aria protein for women: a combination of 50% whey, 50% soy protein

In summation, protein powder supplements can be a great way to sneak some protein into your diet. However, choose protein in its most natural form whenever possible and be mindful of the additional calories that protein powder supplies in the diet. 

• Age 60+ and menopausal/postmenopausal
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