The Deal with Protein

The Deal with Protein

People like to say all kinds of things about protein, like, you need to eat lots of it to build muscle, and lose weight. But dietary science is way more complicated than that! You can’t just eat a bunch of one thing to get buff or to be healthy. In fact, eating too much of anything can be really unhealthy. Proteins are a group of macromolecules that do a lot of different things, like helping with chemical reactions or immune responses, Giving our tissue structure and even sending messages between cells. And by understanding the chemical basics of protein, we can understand why we need to eat it to keep our bodies working, so let’s dig in! Chemically, proteins are made up of long chains of amino acids. These organic compounds have an amine group and a carboxylic acid group Plus some other atoms that make up a side chain. These strings fold up because of interactions between the amino acids, making stable 3D structures that are ready to do things inside our bodies. And some proteins, like hemoglobin which ferries oxygen around our bloodstream are made up of more than one of these strings interacting. Our bodies use 21 different amino acids to make thousands of distinct proteins, So it’s important we have all of these building blocks for ourselves to work with. Amino acids can be broken down to three types: Essential, Non-Essential and Conditionally Essential. Essential amino acids are the ones that our bodies need to function but have no way of making. So that’s where food comes in, like meat, beans, nuts and eggs. The digestive system breaks down the proteins in food; first you basically untwist, or denature the 3D structure of the protein with stomach acid. Then, you chop the chains into chunks of one or two amino acids, using these specialized proteins called Proteases. These amino acids are absorbed into your bloodstream and your small intestine, and sent around your body to be assembled into new proteins. So what about the non-essential amino acids? We still need them and we can get them from food too, but our bodies can make them out of other chemicals that are hanging around. For instance, one of the intermediates from the energy making citric acid cycle Alpha Ketoglutarate can undergo chemical reactions to make four amino acids: Glutamate, Glutamine, Proline, and Arginine. So for the most part your body’s got you covered, Except when it’s still developing, sick, or injured, and can’t naturally produce enough of some of these amino acids. We call them conditionally essential. For example, pre-term infants can be deficient in Arginine, which causes a variety of health problems in the heart, lungs, brain, and intestines. And scientists think their still developing bodies aren’t synthesizing enough of the proteins that help with those chemical reactions that make the Arginine. So now that we know the basics, what’s up with all of these protein powders and shakes and bars and pills? Why do people have these expectations that they will build muscle? When people talk about building muscle, they’re probably talking about skeletal muscle the type that’s attached to your bones and you can voluntary move around like your quads and biceps. Skeletal muscle is made up of bundles of muscle fibers, which are basically a membrane surrounding these units called Myofibrils. And myofibrils are essentially bundles of these long proteins called Actin, which are thinner, and Myosin, which are thicker. When you contract a muscle, these protein filaments slide past each other, with myosin driving the movement. So your muscle tissue is constantly making and breaking down proteins, and your muscles grow when there’s more protein synthesis than breakdown. Exercise is just a way to stimulate chemical pathways that cause more protein synthesis. When you work your muscles harder than usual, the extra tension on the muscle fibers can cause these microscopic tears, either damage to the cell membrane, or the connections between actin and myosin filaments. And this damage can signal for more protein synthesis. When your body repairs muscle fibers and creates new tissue, it makes more actin and myosin too. But it’s not clear if you need to damage your muscle for growth. If you eat protein when you work out, your body mostly just has more amino acids hanging around to synthesize proteins in your muscles. And your body doesn’t really store extra amino acids for later. They get converted into other organic compounds, that are used in metabolic pathways, like glucose or Acetyl-CoA, or they get broken down and eliminated in urine. So that’s pretty much the basics of protein. They’re super important for all kinds of bodily functions, and you make them from amino acids, which you can synthesize on your own or get them from your food. And you cannot expect protein supplements to have magic muscle building powers. They’re pretty much just another way to take in sustenance, and for your body to absorb amino acids. Thank you for watching this episode of SciShow, which was brought to you by our patrons on Patreon®. If you would like to help support this show, you can go to And if you want to keep getting smarter with us, don’t forget to go to and subscribe!

100 Replies to “The Deal with Protein”

  1. So are you saying that athletes and body builders really don't need to be drinking protein shakes everyday, or consistently?

  2. Hank is like the professor that goes just a little too fast and it all makes sense but halfway in you have no idea what you're talking about anymore

  3. Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms and participate in virtually every process within cells. Many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions.

  4. Whats up people. 25% off your order when you spend 30 dollars for protein powder.

  5. Did someone say the word "vegan?" I feel like this video got preempted. No one pulled your cord…go on, Git! waves a broom at vegans menacingly

  6. The funny thing is, when the amino acids are deaminated, the keto acid produced can be converted into glucose and stored as glycogen in your liver. So if you're eating a tonne of protein and not exercising after, it essentially just goes to waste, part of the molecule is pissed out and the other part becomes a storage molecule or adipose fat. The majority of people in developed societies consume more protein than is required for their body and level of activity so it's just ironic that people put so much emphasis on it in diet

  7. If anyone is looking for a really easy to digest and gluten free protein you should try out hemp seeds which has more protein by weight and volume than any meat or fish or any other plant based protein you can find in nature! It also will give you a good combination of omega fatty acids which help your cells grow and divide properly.

  8. "Too much of anything is bad for you."

    That's why I worry about all the corn products in our food. There's no way that can be good for us. Just look at the label on what you eat and count each thing made of corn, some of them multiple times. Ever wonder what effect it all might be having on your health? :

    High Fructose Corn Syrup
    Modified Food Starch
    Monosodium Glutamate
    Vegetable Oil

  9. BRO TIP: If it sounds too hard, it's not bro science, it's real science. And that's for nerds, not gnars.

  10. Just to clarify on the practical application of protein in muscle building:
    Protein is what is considered a macro nutrient, alongside carbs and fats. All three macros are important for muscle building and are needed TOGETHER to achieve growth.
    The subject of the ratio between carbs, proteins and fats in your diet is a hot topic in the bodybuilding community and can look quite daunting to someone just starting out.
    A great source for anything fitness and diet related is Bodybuilding(dot)com. You can find a lot of credible, scientific supported information for a lot of subjects. Go learn about the caloric amount your body needs when you're working out, the ratio of macros in your diet to support your fitness goal and about each macro itself and the different types you need to get in your diet.

    Hope that helps someone.

  11. 1-3gram of protein to every kg of your body so if you are 70kg and eat like 1,5gram to every kg so you need 105gram of protein.

  12. I'm sad you didn't mention that there's protein in every plant since a common misconception is that protein is the same as meat!

  13. Scishow you didn't say why people take supplements of protein.
    It's because it's easier to supply body with spoon of protein powder rather than having to eat another breast of chicken

  14. Ok…. so Amino Acids just do……..everything??? Like, what is the difference between regular Amino Acids and these Branched-Chain Amino Acids body builders and other athletes take as supplements? And what EXACTLY do they do?

  15. So does it matter whether you eat protein or carb rich food before a workout? Is it best to have both? Or should you eat one first and the other after? There's so much conflicting info online, most of it not backed up by studies or even known biology, so I don't know what to believe.

  16. My professor told us that excess protein "is absolutely detrimental" to our health and that we really don't need to consume much protein in our diet. He claims that protein bars and shakes are pretty unnecessary

  17. Wanna hear a joke people? 2 words. VEGAN GAINS. Don't be stupid and eat enough quality protein. It doesn't need to be meat if you don't wanna too. Eggs and whey (and fish if you eat them) are superb protein sources for vegetarians and are good for your body. Don't get brainwashed by so called "vegan food police". I had been vegetarian for years and you won't believe me how much healthier i am eating quality whole foods – animal souces included.


  19. forgive me if you've made a video on it, but could you explain ketosis? I've heard a ton about it and understand the basics but not the science. thank you, I really enjoy this channel:)

  20. So, if you get your RDA of every amino acid from your diet but don't actually eat any protein (which are just bundles of amino acids and nitrogen that we break down into their constituent amino acids) do you actually need protein? Probably a stupid question, but one I've always wondered and never could find the answer too.

  21. People I know who workout and take these protein supplements claim that it makes the protein available for your body to use.
    Explaining to them that your body already makes all the protein you eat available for use does no good the powder has magical properties that make it's special and I am the one that don't doesn't understand.

  22. Athletes that workout 4-5 times a week with a variety of intensity need more protein than the average person. In fact it's often the case that athletes get less protein in their diet than what they need. Whey protein help serve this purpose, for athletes or individuals that exercise and have physically demanding jobs. It doesn't mean that an individual that is working out with the same frequency and intensity as an athlete doesn't need more protein as well. Maintaining a healthy and balanced diet is difficult in itself but with exercise even more challenging. More protein does not mean less fruits, vegetables, monounsaturated/polyunsaturated fat, and other vitamins and minerals. It's important to consult your doctor about working out and changing your diet. Athletes and individuals with physically demanding jobs even more. Be proactive about your diet learn about food labels, product claims, calculate your BMI and body fat. Don't get discouraged about the results! Take small steps to make healthy food choices eat lean meats, balance eating complex carbohydrates, try a various types of vegetables, and eat healthy fats. It's REALLY hard to maintain a healthy diet, it's hard for athletes too, remember that and don't give up.

  23. I love these nutritional videos. Cutting through all the food/diet BS we wade through on a daily basis with real science. Please make one about cholesterol, since I've never really been able to figure it out; and another that looks at simple sugars in more detail. I get so sick about people going on about HFCS like it's poisonous evil Satan-juice, rather than just an inexpensive blend of normal common sugars.

  24. You definitely need to damage the muscle tissue to build significant muscle mass. No bodybuilder in the entire world would say otherwise. Why would you say this is "not certain", that's just absurd

  25. You don't need meat to get any nutrition because you can get a lot more from grains and legumes ,soy beans , lentils so on …..

  26. > has a digestive disorder that prevents me from eating peanuts or beans
    > but I can digest meat and eggs (most of them anyway)
    > basically I cannot become vegan without running out of essential proteins. 🙁

    I also have serious fatigue problems and a possibly malfunctioning metabolism, so who knows how many of these optional proteins are actually essential to me. I'm already getting amino-acid supplements from my doctor just in case lol

  27. I used to eat meat and take protein supplements. Now I'm a mostly vegan vegetarian, don't take any supplements and feel like I'm missing nothing. 😀

  28. Can having these "muscle building" protein shakes on a regular basis without exercising lead to obesity? Or weight gain in fat and not weight gain in muscle weight?

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