The major types and functions of proteins are:
Antibodies: protect the body from foreign particles, such as potentially pathogenic microorganisms (viruses, bacteria, fungi), by binding to them and “tagging” them for rapid elimination
Enzymes: help form new molecules and catalyze chemical and metabolic reactions
Messengers: communicate signals between cells to maintain bodily processes
Structural components: proteins that act as building blocks for cells that allow the body to move
Transport/storage proteins: move molecules throughout the body
Dietary proteins provide the “essential” (unable to be synthesized in the human body) amino acids for our neurotransmitters, chemical messengers, and muscle cells. Here is where we come to a controversy of the “proper” sourcing and the exact amounts of protein that are needed for optimal health. While some people consider “protein” synonymous with “animal,” there is an emerging trend to substitute with plant-based alternatives instead. Almost every type of food will have some types of amino acids in it, and therefore can be considered a source of protein. Vegetables, grains, legumes and mushrooms provide varying degrees and classes of proteins.
It’s a fact that only animal sources (eggs, poultry, red meat) provide the 9 essential amino acids in tandem, and they are densely packed sources, both in nutrients and calories. However, the principle of “food combining” non-animal sources together to get the 9 essential aminos works just as well. As it happens, the combination doesn’t even need to happen within a single meal. As long as we are rotating the types of proteins, and therefore aminos, we are consuming within a couple of days of each other, the combination will work to provide all 9 essential aminos.
As for optimal daily protein intake levels, it really depends on a person’s individual needs. Levels of activity, age, gender and specific nutritional needs (for malnourished or pregnant people, for instance) all play a role in calculating one’s daily protein levels. A young professional athlete may have different needs from a retired middle aged person, for instance.
The Recommended Dietary Allowance (RDA) for protein is only 0.8 grams of protein per kilogram of body weight, which translates to roughly 10-35% percent of total caloric intake. Since the RDA is the minimum amount of a nutrient you need to meet your basic nutritional requirements, some sources estimate that up to 2.0 g/kg of body weight may be appropriate depending on a person’s nutritional needs. People who are highly active, or who wish to build more muscle should generally consume more protein. This protein calculator is a helpful tool to determine how much protein you may need, factoring in age, gender, and caloric requirements.
And what about protein powders and amino acid supplements?
As a proponent of whole foods, my stance on this is that protein powders do not compare to having real, whole foods. Protein powders and supplements are marketed as muscle-building blocks with anti-inflammatory effects. While this can be true, any isolated part that’s extracted, multiplied and consumed can have undesirable effects. The truth is that nutritional science doesn’t have all the facts, and the supplement industry has a lot of marginally evidence-based claims as part of a marketing effort. Any component of a food or plant that’s extracted, doesn’t have the benefit of synergy of all the other ingredients it was taken from.
Protein supplements are touted to help athletes or vegan dieters with additional protein needs. However, eating real food is preferable because our bodies are designed for real food, and not food-like imitations. Our bodies actually recognize real food and are able to digest it optimally, and use each of their components appropriately. Giving it pure protein, along with some additives and flavorings, may just confuse the body on some level. Sure, muscle growth can be improved, but at what cost? We just don’t know the long-term effects or drawbacks fully as yet. So do your body and the planet a favor, save those plastic cans and bottles, and pass on the powders and pills. Enjoy and savor a delicious meal incorporating plant-based protein sources instead!
[**Note: preparing grains and legumes in specific ways can unlock micronutrients and reduce anti-nutrients, which usually interfere with digestion and absorption of nutrients.]
(1) “How much protein do you need every day?” Harvard Health Blog. 18 June 2015. https://www.health.harvard.edu/blog/how-much-protein-do-you-need-every-day-201506188096