Protein — the nutrition facts
Get the bars in, shakes on and a bucket of meat cooking. Everyone knows that to bulk up on muscle and keep our body fuelled we need to eat shit loads of protein. Muscle is made of protein, so obviously that makes sense. Or does it?
Let’s start with the metabolism of protein from start to finish. This has been worked out over many years by clever and interesting experiments revolving around nitrogen balance, some of which involve keeping people in a hospital ward for many weeks and finely controlling their diet until we know just how much protein they need to maintain their body weight.
Protein is the name given to combinations of the 22 amino acids that combine to make a strong and functional structure we call protein. We most often associate protein with muscle but there are vast amounts of proteins, big and small, that do amazing things in our bodies. Some diseases are caused by problems with proteins that perform important functions in our bodies.
Of the 22 amino acids, our own bodies can make 13 of them from ingredients we eat in our normal diet — that’s a normal diet, not a superfood, clean eating, high protein, supplement mad diet, just a good old fashioned balanced diet. There are 9 amino acids that our body cannot produce itself so we call these essential amino acids, as we need to eat them in our diet to provide our body in sufficient quantities.
Is protein just meat?
No. Nearly everything we eat and drink has some protein in it. Meat just happens to be mostly protein so it’s associated with ‘building muscle’ by the marketing crowd. Think of a big fat juicy steak, now think of the cow it came from. What do cows eat? Where do cows get the protein to make the juicy steaks? Grass, that’s right, grass.
So having established that protein comes from other sources than meat this opens the door for this question; Do we need to eat meat?
Now that is a topic in itself which is why I’m treating it that way and doing a whole article on that very soon.
In the simplest terms our bodies have no conscious about where the nutrients come from in our diet, we as consumers on the other hand have to consider the moral and ethical values of where our food comes from. There is a need for protein in the diet and it must be met or we will fail to maintain our body weight. We are perfectly capable of getting all our protein needs from plant sources.
Questions such as do we need to eat meat, is a vegan diet healthy, does eating x,y,z cause cancer are flawed in most respects as they are nebulous and not specific enough to test in the form asked. The fundamental issue with these questions is that they are black and white. Life and our bodies just don’t operate on a black and white scale. My advice is always to question everything, especially information presented as black and white or as the definitive ‘answer’ to a problem. It may of course be correct but it should be backed up with high quality evidence.
How much protein do we need?
In a way this is the simplest question to answer as it is something that is relatively easy to test. Based on the experiments of putting people in a controlled environment and feeding them a strictly controlled diet with decreasing amounts of protein until they can only just maintain their body weight we know that the average protein requirements for an adult human are 0.65g/kg per day to maintain your body weight. We need to be careful here to keep in mind that this is to maintain your body weight — that is to stay in a protein equilibrium or balance.
If we look at the current dietary protein guidelines we can see that they are higher than the above figure. That’s not a mistake, in developing the guidelines they were set to two standard deviations above the average to account for variation within the population. Setting the guidelines above the minimum requirement is to ensure that everyone’s protein requirements are met if they aim for the guidelines. For a 70 kg adult the recommended protein requirement per day is about 58g, in developed countries the average protein consumption is around 90g per day so we far exceed our needs on average already. Your average chicken breast cooked provides about 46–66g of protein based on USDA data.