Chances are you’ve heard a high protein intake is necessary for building muscle, burning fat, and living an overall healthy life, but how much protein do you actually need? Do you really have to slam protein shakes every couple of hours?
Protein is one of the three macronutrients — the other two are fats and carbohydrates — that our body uses in large amounts to function properly. Proteins are the building blocks of life, and for good reason: it is an important component of each and every cell and process in the body. Without it, we wouldn’t exist!
Protein is made up of small molecules called amino acids, which play critical roles in the body. Their most well known function is building tissue, but they are also required for the synthesis of hormones and neurotransmitters which regulate our bodily functions such as metabolism, immune system, and more. There are 20 amino acids that the body uses, of which 9 are considered to be ‘essential’. These essential amino acids are ones that your body cannot produce and must be obtained through the diet. Deficiencies in any of the essential amino acids can negatively impact the body, leading to problems with the nervous, reproductive, immune, and digestive systems.
Foods that contain all the essential amino acids are known as complete proteins. The best sources of complete proteins are animal products like red meat, eggs, seafood, and poultry, though several vegan sources such as quinoa and soy also contain all the essential amino acids.
As I mentioned earlier one, of protein’s biggest roles in the body is to build muscle/tissue. The problem is, how exactly can we tell if we’re providing the body with enough building blocks?
Of the three macronutrients, protein is the only compound that contains nitrogen. When you consume protein, nitrogen enters your body. After your body breaks it down and absorbs the amino acids, you’re left with compounds like ammonia, urea, and uric acid which are excreted from the body through your urine. When the amount of protein you take in matches the amount you excrete, you’re in nitrogen balance.
If you don’t eat enough protein you’ll be in negative nitrogen balance, otherwise known as a catabolic state (muscle breakdown). If you eat a surplus of protein you’ll be in positive nitrogen balance, or an anabolic state (muscle gaining). While this anabolic state is obviously needed to build muscle, there are some issues that come up when you eat an excess amount (personal anecdote in a bit).
One misconception is that a high protein intake will harm your kidneys. Some believe that your kidneys need to work hard to clear the metabolites of protein from your body, leading to increased strain on the kidneys. Unless you have existing kidney issues, this is actually not a concern as the amount of ‘strain’ this adds is negligible to what your kidney already has to process on a regular basis.
When I began my fitness journey, all the articles I read recommended 1 gram per lb of body weight, or 2.2 grams per kilogram, as a minimum. Individuals looking to cut were to increase their protein intake to 1.5–2 g/lb, since being in a caloric deficit puts you in a catabolic state and causes your body to ‘eat away at itself’.
Armed with this knowledge, I upped my protein intake to 250–300g/day. What could possibly go wrong if the internet told me this was the way to go? Oh boy. Let me tell you. A noticeable negative impact on my digestion, which lead to the nastiest, most putrid farts in the world. I’m not kidding. And the worst part? I’d fart ALL THE FREAKING TIME. My poor, poor colleagues… anyhow. Moving on.
The truth is, there is no one size fits all equation here.
The USDA recommends about 0.36g/lb (0.8g/kg) of body weight, but this recommendation is for the completely sedentary person. The ‘right’ amount of protein you should eat is influenced by a myriad of factors such as activity level, age, muscle mass, digestion, as well as your goals. While I can’t prescribe a specific number for you, here is what the research shows for people who live an active and healthy lifestyle (read: not completely sedentary).
If your goal is to simply maintain muscle, research has indicated that you won’t receive much additional benefit from going over 0.55g/lb (1.2g/kg) of body weight (1).
If you want to build muscle, you should up the protein to anywhere between 0.6–0.82g/lb (1.3–1.8g/lkg) of body weight to maximize muscle protein synthesis (2). Of course, you will need to complement this higher protein intake with a resistance training program to send that muscle building signal to the body.
If you want to hold on to as much lean muscle mass as possible while losing body fat, upping the intake slightly to 0.9g/lb (2g/kg) of body weight could be beneficial in sparing muscle tissue while in a caloric deficit (2).
Now I understand you probably don’t want to deal with all these numbers — hell I don’t want to either. It’s safe to say that consuming anywhere between 0.6–1g/lb (1.3–2.2g/kg) will probably cover your bases. It may be worth staying on the higher end of that range if you’re cutting just to play it safe.
I’ve experimented with everything from about 0.55g/lb to 2g/lb of protein, and I guarantee that anything over 1g/lb is excessive. I try to stay around the 0.8g/lb mark since research shows that’s where you’ll maximize the anabolic effect of protein. This ends up being 136g of protein at my current weight of 170lb, though I honestly drop into the 120s on many days as well. So what does a day of eating look like for me to hit my protein requirements?
Meal 1: 5 egg scramble with a side of spinach and avocado, ~35g of protein
Meal 2: Big ass salad with a 4oz salmon filet, ~30g of protein
Meal 3: 10oz ribeye steak with veggies & sweet potato, ~70g of protein
As you can see, hitting the high end of my protein intake doesn’t require much food. If you aren’t able to estimate how large your portions are, I’d strongly recommend investing in a scale to weigh your food out. After a couple of weeks you’ll be able to eyeball portion sizes like a champ and ensure you’re getting enough protein each day!