You may not really understand what whey protein is, which is why we’re here. Adding whey to your daily diet is a safe way to support fat loss and muscle gain. From the origins of whey to its many benefits to its many varieties, here is your complete guide to this highly popular muscle supplement.

What’s Whey Protein?

Whey comprises 20 percent of the protein found in cows’ milk. Whey has always been considered a byproduct of cheese production. Farmers used to think it wasn’t worth keeping it so they actually threw it out. The rest of the 80 percent of the protein found in milk is casein, used in the making of cheese. If you used to love nursery rhymes when you’re a kid, you may recall the expression “curds and whey” – which refers to a meal of cottage cheese. The casein comprises the cheese curds and the whey is the liquid in which they lie.

It wasn’t till the mid-20th century when nutritionists discovered the value of whey in and of itself. This was when it started to get popular as a supplement. The U.S. Dairy Export Council says there are 6,000 whey protein products that are sold globally. Between 2010 and 2015, the amount of whey products grew by 34 percent, compared with six percent between the years of 2005 and 2009.

Whey Protein: The Benefits

People use whey for the following benefits:

To Support Muscle Gain

As a complete protein, whey has all the amino acids that are essential and must be ingested via food because the body cannot make them. Thus, whey has an advantage over plant proteins like rice, which must be combined with protein powder or food to provide all the aminos necessary in all the proper amounts so the body can build up muscle. One scoop of whey protein powder (25 grams) gives about 20 grams of whey protein.

The leucine content is what draws bodybuilders to whey protein. This is a BCAA (branched-chain amino acid), with research showing leucine is the most important amino for support of muscle growth. The International Society of Sports Nutrition (ISSN) in 2017 released their stand on protein and what is needed for exercise. If you want to maximize muscle gain, it’s recommended that you eat between 20 and 40 grams of protein, spreading it out among three or four meals daily. Each meal should contain 0.7 to three grams of leucine, on top of a good balance of all essential amino acids.

A single serving of whey will give you a great daily serving. Most small portions of meat and poultry provide at least two grams of leucine. A 25-gram scoop of whey protein powder has between two and 2.5 grams of leucine. The Journal of Applied Physiology says this is more per gram than any other protein source like milk, eggs, milk, casein protein and soy protein.

It Promotes Faster Recovery

After finishing a workout, your muscles crave protein—and leucine will help rebuild them bigger and stronger. One study by Medicine and Science in Sports and Exercise showed that whey protein gives leucine to the muscles more rapidly than casein, which stimulates muscle protein synthesis more quickly. This is why whey protein is the best post-workout choice. Casein does have benefits, too, as it digests more slowly. This is why it’s a better protein choice before going to bed. It actually feeds your body leucine throughout the night gradually as you sleep.

It Helps With Body Recomposition

Even if you don’t want to get jacked, whey can help you improve your body composition, which supports both muscle gain and fat loss. A 2014 Nutrition Research study revealed that, whey promotes better changes in appetite, body mass, body composition, and waist circumference compared with soy protein – when subjects drank whey protein before consuming their biggest meal during the day.

Whey also helps you lose a lot of weight, A 2017 meta-analysis revealed that whey helped with overweight or obese individuals who wanted to lose fat and reduce risk factors that could lead to cardiovascular disease.

It Maintains Overall Health

Whey has many heart benefits. One study in Appetite found that overweight people who engaged in strength training while supplementing with whey protein had high levels of glutathione. This is a molecule responsible for supporting cellular health. It also increased HDL cholesterol after six weeks as compared with a control group that didn’t supplement.

One trial by the International Journal of Food Sciences and Nutrition revealed a linear relationship between how much whey protein was consumed and a boost in glutathione levels. Those who consumed 45 grams of whey each day for two weeks increased their glutathione by 24 percent.

It Helps You Reach Optimal Protein Intake

Similar to other protein supplements, whey helps you reach your total daily protein intake. The recommended daily dose of protein by the government is 0.8 grams per kilogram for those who don’t exercise. That number should be tripled for those who engage in strength training, equal to one gram per pound of body weight. And if you are engaging in strength training and you’re eating a calorie-restricted diet, you’ll need between 2.3 and 3.1 grams per kg of lean mass.

Someone who weighs 200 pounds with 15 percent body fat should start with a lean body mass of 77 kilos, or 170 pounds. You would have to take in 177 to 238g a day of protein, which is tough to get solely from food. You could take 20 grams of the whey protein to close up that gap, and give you a quality protein source that will give your body the best benefits.

Whey Isolate or Whey Concentrate?

There are several kinds of whey out there. The most popular are whey protein isolate and concentrate. A concentrate is not filtered as much as isolates can be, which means it still has a lot of the fats and carbohydrates in the originating milk. Whey concentrates are 70 to 80 percent protein, and are thus more affordable to purchase.

Whey protein isolate is the best type of whey protein you can get, with nearly all the fat and carbs taken out. You get a powder that is 90 percent protein or more. Because there is no fat to slow down digestion, you will want to consume whey isolate immediately after your workout. If trying to avoid excess calories, or are crazy about your macros, whey protein is a great option for dieters.

Hydrolyzed Whey Protein

Another option is hydrolyzed whey protein, also known as whey protein hydrolysate. This is a whey isolate whereby its protein chains have been broken down into little pieces. Basically, the manufacturer did part of the work of digestion for consumers, which means when you do consume the protein, it gets absorbed even faster and will reach your muscles quicker than if you were to take just an isolate.

This is why hydrolyzed whey is best for athletes with intense training schedules and who may be engaging in twice-a-day workouts. An example of this is MMA fighters who lift weights in the a.m. and do fight training in the p.m. Another example includes wrestlers or tennis players who must engage in multiple competitive bouts in a day, as with a tournament.There’s very little time between sessions, so speed of recovery is a priority. A study appearing in the Journal of Science and Medicine in Sport showed subjects who took hydrolyzed whey fully recovered about six hours later.

But there’s no big advantage of hydrolyzed whey over your basic whey protein isolate. A trial that appeared in the International Journal of Food Sciences and Nutrition said that whey isolate had quicker absorption of leucine as compared with a whey hydrolysate. Whey isolate also happens to be less expensive and is just fine for all types of fitness-seekers.

Whey Protein or Grass-Fed Whey?

Some companies distinguish their whey protein as originating from grass-fed cows. But in What The Health documentary, we show that grass-fed meat and dairy offers more health benefits with fewer toxins than originating from animals in a factory farm. If you care about the humane treatment of cows and would like to support a sustainable whey protein source, go with the grass-fed variety.

Mass Gainer or Whey Protein?

Supplement companies who make supplements to help people gain weight will sell products known as mass gainers. They have whey protein in them as well as other ingredients you don’t really want to see in your powder, such as sugars and fats that boost calorie count. This can actually lead to more body-fat gain than lean-mass gain.

If you’re looking for a denser shake, make your own so you have control over the amount and quality of what’s in it. Blend a banana and some nut butter with your choice of chocolate-flavored protein powder and voila – you have a delicious smoothie.

What Should Whey Protein Have?

On top of having a good-quality protein source, whey powder should include compounds that make it easier to digest so the protein is more easily assimilated and delivered to your muscles. A 2017 study showed that probiotics like bacillus strain can maximize the level of absorption and bring more benefits in regards to protein supplementation.

Digestive enzymes can also help. Be on the lookout for a powder that’s got protease, which helps the body break down protein. But even the purest whey isolate powders will have at least a small amount of fat and carbs in them. These don’t come from milk but will be added separately by other manufacturer sources to boost flavor. This is actually a good thing because whey has a bitter taste when on its own). This is why you want enzymes to break down fat and carbs as well, like amylase and lipase.

Does Whey Protein Result in Kidney Damage?

There are rumors out there that a high intake of protein may lead to kidney problems and some other health risks. In 2017, the media reported on the death of a female bodybuilder who overdosed on protein supplements. But then CNN reported that the woman suffered from a rare disorder whereby her body couldn’t properly break down protein. This led to a buildup of toxic ammonia levels in her system.

One study in the American Journal of Kidney Diseases says there are renal-related risks to incorporating high-protein diets in those with healthy kidney function. In the end, unless you have a pre-existing condition, you can have your daily protein shake with confidence.

A 2016 study appearing in the Journal of Nutrition and Metabolism showed that males who engaged in strength training and ate a high-protein diet for six months experienced no harmful effects on blood lipids, liver, or kidney function. They did, however, alternate the high-protein intake offset by the same amount of time to follow their normal diets – much lower in calories. So even with the total increase in energy intake as part of the high-protein phase, participants didn’t see an increase in fat mass.

Should You Take Whey Protein Before or After Your Workout?

Many nutritionists say you should consume whey protein afterward. You may have heard the term “anabolic window,” which is the hour or so you have to recharge your muscles and give them a boost of protein before recovery is endangered. But the ISSN says that window will last for 24 hours or even longer. As long as you’re eating a proper amount of protein throughout the day and into the next day, you’re covered.

But you’ll still need lots of protein on the regular, which is why having a protein shake right after your workout is so popular. Not only is it fast-acting, it’s convenient, ensuring the protein gets into your system without the need to prepare a big meal. It also helps to get protein into the muscles sooner than later when you’re an active person or an athlete with quick recovery needs. Whey’s quick digestion makes it a good choice immediately after a workout.

Can Protein Bars Be Healthy?

Whey protein powder shakes tend to be digested quickly, which means they’re not the most filling thing in the world. When people can’t eat a full meal or have a shake, they often grab a nutrition bar with lots of protein in it. They aren’t as messy as a shake, plus they are easier to carry and are overall more satisfying to eat. But many bars and chewable protein snacks are high in fat and sugar. They are often touted as high-protein alternatives to sweet and unhealthy candy bars, but in reality they’re not that much better, aside from the fact that they pack more protein.

Be on the lookout for bars and snacks that have just a few grams of sugar, as well as five or more grams of protein within one serving. You could also add a few grams of fiber too. One Australian study said that those who ate high-protein and high-fiber bars had lower blood sugar levels than people who consumed more sugary snack bars. Plus, they ate fewer calories at meal time.