Yogic diet: where to get protein?

"The body needs protein," say people who are not very familiar with vegetarian food. It seems to them that without meat, fish and eggs in the diet, vegetarians are forced to eat "nothing but grass," and so there is nowhere to get protein from. That is not so. Modern research has shown that, as long as the menu is varied, a vegetarian diet can fully cover the body's need for protein. And the very idea of a large amount of protein in the diet has long been outdated.

Why do we need protein?

Proteins are organic substances made up of various amino acids. Their role is to maintain muscle and bone mass, support the immune system and prevent fatigue.

The main functions of protein

• Transport. Delivering various substances to tissues and organs (hemoglobin, transferrin, etc.).
• Energy. Supplying the whole body with energy.
• Motor. The proteins actin and myosin make all kinds of movement possible.
• Protective. Special proteins (antibodies) take part in the work of the immune system, neutralizing foreign substances.
• Structural. Taking part in forming cellular and extracellular structures (keratin — hair and nails; collagen — cartilage and tendons).
• Catalytic. Speeding up the biochemical reactions that take place in cells.
• Storage. Storing certain substances in the body as a reserve.
• Regulatory. Taking part in regulating metabolic processes.

Protein and amino acids

Proteins are absorbed during digestion, when, under the action of special enzymes, they break down into amino acids. The amino acids enter the blood and are then used to build the body's own protein. And the norm of amino acid intake is no less important for the body than the norm of protein intake itself. In all, 20 amino acids are involved in building the body's own proteins, and 12 of them can be built by our body on its own.

Only 8 amino acids are not synthesized in the human body and must come from food. These amino acids are called essential.

The proportions of essential amino acids in animal and soy protein are similar to the proportions of amino acids in human protein. Such proteins are called complete. Plant proteins, with the exception of soy proteins, contain smaller amounts of amino acids than animal proteins. And they are called incomplete.

Table 1. Essential amino acids (intake norms recommended by the WHO)

| Essential amino acids | Milligrams per 1 kg of body weight [2] | Grams per 1 kg of body weight | Daily intake in g for a person weighing 80 kg |
|---|---|---|---|
| H Histidine | 10 | 0.01 | 0.8 |
| I Isoleucine (BCAA) | 20 | 0.02 | 1.6 |
| L Leucine (BCAA) | 39 | 0.039 | 3.12 |
| K Lysine | 30 | 0.03 | 2.4 |
| M Methionine + C Cysteine | 15 | 0.015 | 1.2 |
| F Phenylalanine + Y Tyrosine | 25 | 0.025 | 2 |
| T Threonine | 15 | 0.015 | 1.2 |
| W Tryptophan | 4 | 0.004 | 0.32 |
| V Valine (BCAA) | 26 | 0.026 | 2.08 |
| | | | Total 14.72 |

However, we shouldn't rush to conclude that a plant-based diet is inadequate. In fact, plant proteins also contain all the essential amino acids, only in smaller proportions. For example, legumes contain less methionine, and most other plant foods have less lysine.

Vegetarian foods containing essential amino acids

• Valine, threonine, phenylalanine, leucine: dairy products, especially farmer's cheese, wheat sprouts, oats.
• Isoleucine: milk, yogurt, hard yellow cheese.
• Tryptophan: cottage cheese, milk, yogurt, peanuts, legumes (especially soy), wheat, buckwheat and barley groats, wheat bran, walnuts and pumpkin seeds, beans, cauliflower, spinach.
• Lysine: yogurt, hard yellow cheese, nuts and seeds, cereal grains, legumes, beans, peas, soy, spinach, Brussels sprouts and cauliflower.
• Methionine: milk protein, wheat groats, wheat bran, rice, walnuts, beans.

The norm of protein intake

So how much protein does a person need per day? There are very different opinions on this. And here it is important to take into account a person's age, lifestyle, the intensity of their physical activity and so on.

Table 2. The ratio of essential amino acids to total protein

| | Total protein per 100 g | Essential amino acids per 100 g | EAA / total protein |
|---|---|---|---|
| Egg white | 12.56 g | 6.39 g | 51% |
| Parmesan | 39 g | 20.7 g | 53% |
| Beans | 23.58 g | 10.25 g | 43% |
| Chickpeas | 20.47 g | 8.28 g | 40% |
| Walnut | 15.23 g | 5.69 g | 37% |
| Buckwheat (grains) | 13.25 g | 4.9 | 36% |
| Wheat (grains) | 10.9 g | 4.59 | 42% |
| Rye (grains) | 10.34 g | 2.75 | 27% |
| White cabbage | 1.28 g | 0.23 g | 23% |
| TOFU (soy) | 9.98 g | 4.2 g | 42% |
| Button mushrooms | 2.11 g | 0.68 g | 32% |
| Potatoes | 1.68 g | 0.556 g | 33% |

Many international norms for protein intake were not revised for a long time. As the American biochemist Colin Campbell writes in his book "The China Study," ever since protein was discovered in 1839 by the Dutch chemist Gerhard Mulder, this nutrient has been the most revered of all. You can tell this even from its name, which comes from the Greek proteios — "protein" — meaning "of prime importance." Scientists of the past, such as the eminent German physiologist Carl Voit, one of the founders of nutrition science, were great champions of protein. Voit found that a person needs only 48.5 g of protein a day, yet he recommended consuming a huge dose of 118 g a day. This had to do with the cultural attitudes of the time. Protein and meat were considered synonyms, and everyone strove to include meat in their diet, just as many people today strive to have more spacious houses and faster cars.

The authority of these scientists was so great that for a long time these norms were not revised. But over time they began to change. Today the protein norm has dropped considerably, and the latest discoveries and observations in the field of extending human life span have shown the need to reduce it even further.

Today the World Health Organization (WHO) recommends a daily protein intake for men and women of 0.66–0.8 g per kilogram of ideal body weight. The Food and Nutrition Board of the US National Academy of Sciences, for its part, sets the recommended daily dietary allowance of protein at 44–56 g for adult men, 44–48 g for adult women, 76 g for women during pregnancy, 66 g during breastfeeding, and 22–36 g for children and teenagers.

Table 3. How much protein a person needs per day

| Grams per kilogram of weight | In absolute terms for a person weighing 80 kg | Type of activity |
|---|---|---|
| 0.6–1.25 | 60–96 g | For people who are not very active and people who don't do active sports, or for sports that use little energy, such as running and general physical training. |
| 1.25–1.6 | 96–128 g | Active sports, for example weightlifting, powerlifting and CrossFit. Training takes place 3 times a week, as a rule for no more than one or two hours a day. |
| 1.6–2 | 128–160 g | Active sports, with training five times a week, possibly for more than one hour a day (professional athletes). For people who play sports actively and want to lose weight — with the caveats of an overall calorie deficit in the diet and only a short period of taking that much protein. At the same time, we recommend that animal protein make up no more than 12% of the calories in the diet, and that it be replaced or supplemented with plant protein that has a complete amino acid profile [10]. |

A complete diet

It turns out that the idea of protein being supremely valuable in nutrition, and of the vegetarian diet being inadequate, is nothing but a myth. And although most plant proteins contain less of certain amino acids than animal proteins, with the right combination of foods you can reliably supply the body with all the substances it needs. For example, corn proteins contain little lysine but enough tryptophan. Legume proteins, on the other hand, are rich in lysine but contain little tryptophan. So a mixture of beans and corn gives us the necessary amount of essential amino acids.

It's also important to remember foods such as chickpeas, flax and chia seeds, which contain amino acids in concentrated form, and also soy products, which contain about 8% protein whose amino acid composition is very close to that of animal proteins. These foods are quite easy to find today and can be an excellent "insurance" in a plant-based diet.

Sources:

• 1. Chernov A.V. "How much protein does a person need per day?" ("PsychoPoisk," 2019)
• 2. WHO, Protein and amino acid requirements in human nutrition (2007)
• 3. Campbell C. "The China Study" (2013)
• 5. Anna Margolina, "Vegetarianism and Health" ("Nauka i Zhizn," 2010)
• 4. Morton RW, Murphy KT, McKellar SR, Schoenfeld BJ, Henselmans M, Helms E, Aragon AA, Devries MC, Banfield L, Krieger JW, Phillips SM. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults (Br J Sports Med. 2018).
• 5. Young VR, Pellett PL. Plant proteins in relation to human protein and amino acid nutrition. (Am J Clin Nutr. 1994).