Life is amazing. Tiny animals called tardigrades have been shown to survive in the vacuum of space. They join bacteria and lichen as the only things yet known to do so. All three organisms have the basic machinery of life in common though, and so their survival is remarkable.
What is it that allows life itself to exist?
First you need a border wall that allows things in and out in a controlled way. The only way that we have seen this accomplished is with fat. Fat molecules have a characteristic that allows them to make these border walls (cell membranes) really easily and effectively, so all life shares this characteristic membrane, called a bilipid layer.
This means you can never get to zero fat in your diet unless you start eating in a way that includes only staggeringly refined chemical experiments as food (think a diet of powdered sugar alone … blech). Therefore, even rice, wheat and potatoes contain fat due to the natural architecture of life.
The other unvarying characteristic of all life: rutabagas, tardigrades, lichen, chickens and toddlers, is protein. The machinery of the cell itself is made of protein, and DNA is the code that allows those proteins to be assembled in their protean ways (sorry, had to do it).
So as for fat, also for protein. There is no way to eat a diet of even remotely normal foods and not get protein in it. Again, only a diet of the most extreme processed foods could leave you with zero protein (think a diet of only oil … bleargh).
Even with all of this, sometimes patients come to see us with low levels of protein in their blood; this looks like a dietary inadequacy of protein. So it is possible to eat food and still not get enough protein. Yet it’s interesting when you look at the research in this area. There is really no distinction made between a lack of total calories in the diet and a lack of protein calories in the diet.
In malnutrition research it is almost always described as “protein-calorie malnutrition.” Making categories for disease is a separate field from medicine called nosology. The job of a nosologist is to describe the different diseases. When I diagnose malnutrition, the nosological system doesn’t even have a diagnosis for “calorie malnutrition,” it has to be “protein-calorie malnutrition.”
My experience as a doctor differs. I have not seen a patient who is maintaining adequate body weight with adequate calories in the diet develop protein deficiency by itself. Calorie deficiency, in my clinical experience is required for there to be a protein deficiency. What we know about life suggests this would be the case.
“But Dr. Allen,” you say, “aren’t there specific amino acids that I need that might not be present in brown rice?”
Ah … no.
We have to go back to the primary point here. All cellular machinery is mostly the same. The same enzymes are used to break down nutrients and create energy in every living cell. Thus every living cell has those same proteins which are the core group which you need.
Dr. Garth Davis from Texas is a bariatric surgeon and an obesity medicine specialist. He has written a wonderful book called Proteinaholic that details these issues much more extensively, and I recommend you check it out. The general public has an idea of protein requirements that is wildly off base, according to the book.
There is no report of an isolated amino acid deficiency of a human being on a calorically adequate normal diet. They have only been induced in the laboratory. Even there, it’s typically on bizarre diets that would make me type more nonsense words that sound like up-chucking.
We are a slow-growing mammal with a long lifespan and little cell turnover after adulthood. As babies, our species’ milk has such low protein that it can’t curdle. Babies are adding much more body mass at a much faster rate than anyone capable of reading this article, yet they get only 5% of their calories from protein in their ideal food.
So focus on getting adequate calories, and get them from healthy sources. Even athletes don’t need protein supplements, not even plant-based ones. If you like protein, get it from beans, lentils, chickpeas, quinoa and other foods that have a great nutritional and health profile for you, but please don’t give it a second thought.