Over the next three weeks, I cam going to discuss the three main types of nutrients found in the food we eat. We call these building blocks Macronutrients. These are distinguished from micronutrients like vitamins and minerals because we need macronutrients in large quantities and micronutrients in small quantities. The three macronutrients are protein, carbohydrates, and fat. This week, we will begin with protein.
"Eat more protein" has been a catch phrase in marketing campaigns in the last several years. However, what exactly is protein and why is it important?
What is Protein
Protein is a large molecule chain of various amino acids. While there are hundreds of naturally occurring amino acids, we will focus the 9 essential amino acids. Although there are 22 proteinogenic (or protein building) amino acids in total, these nine cannot be synthesized in our bodies and must come from our food intake. They are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Therefore, it is important that we eat protein sources that will provide all 9 essential amino acids. A food that provides all nine amino acids is a "complete" protein; complete in the sense that no additional amino acids are needed. When a food contains some amino acids, but not all, then it is an "incomplete" protein.
Meat, egg, and dairy protein sources are complete, so the concept of complete, incomplete and complementary proteins is important to those who eat a vegan diet primarily. I remember many years ago when I was in high school biology, I learned that there are to plant-based, complete proteins. However, this is not true. Soy products, hemp seeds, buckwheat, quinoa, and pumpkin seeds do provide all 9 essential amino acids. You should note that hemp seeds, however, do provide very low amounts of lysine, so making sure you eat some beans or lentils which are both high in lysine.
This brings us to another method for those eating a plant-based diet to get the proper protein intake known as complementary foods. The idea here is to combine two protein sources to make sure you get all needed amino acids. For example, eating beans or lentils (high in lysine but lacking methionine) with brown rice (high in methionine, but lacking lysine) provides an excellent balance of all amino acids. Spirulina is a high-protein algae but also lacks methionine, so combining it with brown rice or tree nuts forms a complete protein.
Why Is Protein Important?
Protein is important for the function of almost all cells in your body. Your body needs protein to build new cells and repair damaged tissue. So, if cuts are taking a long time to heal, that could be a sign of protein deficiency. The amino acids that form protein are also the building blocks for enzymes, hormones, skin, blood, muscles, cartilage, and bones. Basically, it is the chemistry set of your body.
While the diets of the day invite you to eat more and more protein, most Americans eat much more than the recommended daily allowance (RDA). The RDA for protein is 0.8 grams per kilogram of body weight. To convert this easily, multiply 0.36 by your body weight in pounds. For example, if I weight 150 pounds, that means I should consume 54 grams of protein per day (about 2 ounces). Yes, that is not very much protein! New research indicates that this number might be too low. In any case, you want to be sure that you are getting high quality protein, but not in excess. A good rule of thumb that many nutritionists recommend is a serving about the size of your palm with each meal.
In general, I would recommend against dairy products as a source of protein. While advertisers claim that milk, cheese, and yogurt are good sources of protein, the fact is that dairy products come with variety of digestive concerns. Therefore, I recommend avoiding dairy. (Note: butter and ghee are fats and will be discussed in a later post.)
I also recommend avoiding processed meats like ham, sausage, salami, and bacon. (Yes, avoid bacon.) Processed meats have a lot of additives and typically come from feed-lot stock. This is one reason why processed meats are classified as "likely to cause cancer."
If you are going to consume animal protein, then I would stick to the following:
- Grass fed, pastured beef
- Wild boar
- Free-range, organic poultry
- Wild-caught salmon
- Organic eggs
If you want to limit yourself to plant-based proteins, then these are all healthy choices:
- Whole grains (brown rice, quinoa, etc.)
- Seeds (pumpkin, flax, chia)
- Tofu, tempeh, and soy-based products (make sure organic, non-GMO and limited quantities)
Problems with Too Much Protein
Finally, my discussion of protein requires a quick look at the dangers of eating too much protein. First, when your body digests protein, especially animal protein, it creates ammonia as a by product. This leads to "keto breath." The build up in ammonia causes ammonia breath and also ammonia in the urine. While annoying, this does not cause any serious health risk as long as you are drinking enough water to allow your body to flush the ammonia build up.
Too much animal protein can leads to too many unhealthy fats. Most animal protein comes with its share of fat as well, especially when processed. For example, fried chicken comes with a good serving of bad fats. Processed meats like hot dogs, bologna, or sausage, often includes a high percentage of fat compared to protein. In part 3 of this series, I will discuss healthy and unhealthy fats.
Finally, research is beginning to show that excess protein, especially animal protein, can contribute to insulin resistance. While still controversial, if you are diabetic, or pre-diabetic, I would be careful to eat moderate amounts of protein, especially animal protein.
Next week, I will discuss the new Public Enemy #1: Carbs