Protein content of tofu is so high, why do some people choose to eat chicken breast, beef and eggs? I will have similar questions before I come into contact with these related knowledge personally. After all, tofu tastes at least better than chicken breast and tofu is cheaper than these things. Why do some fitness friends often see large pieces of chicken breast and eggs instead of cheap tofu?
Actually, it's all very simple. Many bodybuilders don't choose tofu, mainly because the quality of tofu protein is not good enough, and both "content" and "essence" are not as good as meat and eggs.
First, let's look at the protein content of these foods (100g edible part): chicken breast: protein19.4g.
Beef (lean meat): protein 20.2g..
Eggs (average): protein13.3g.
Tofu (average): protein 8.1g. (Nennan Tofu: protein 6.2g ... Old Beidou Fu 12.2g)
Therefore, we can clearly see that, generally speaking, what we call "tofu is high in protein" is actually relative to other plant foods. Compared with animal food, the protein content of tofu can only be regarded as the middle and lower level, and it is not particularly high, which means that tofu has lost in "quantity".
Next, let's understand why the "essence" of tofu protein is not as good as meat and eggs: we all know that "high protein is nutritious", but in fact we can't directly absorb and utilize protein. What we can absorb and utilize is the product of protein's decomposition in the body, that is, amino acids. Generally speaking, there are 20 kinds of amino acids in organisms, of which 12 can be synthesized by healthy adults, and the remaining 8 kinds need to be obtained from food (9 kinds are for babies and 1 kind is histidine). These are called "essential amino acids". To measure whether a food is a high-quality protein food, we must see whether it contains these eight essential amino acids and whether the ratio of these eight essential amino acids is suitable for us.
The existence of these eight essential amino acids makes tofu not the best source in protein. Because the methionine content in tofu is relatively lacking, not lacking, but the content is not enough. If tofu is taken as a single source of protein, methionine will be deficient for a long time. This amino acid is closely related to the synthesis of hemoglobin and some functions of spleen, pancreas and lymph. In a word, if we only eat tofu as the source of protein, it will have an impact on our health. But methionine is also called methionine, because the content of egg components is relatively high, which can be used as a supplement.
Seeing this, some friends may ask, "Since the quality of plant protein is not high, why are all the animals that eat grass so strong?" . We often describe a person as strong and may say "as strong as an ox". Cows are representatives of strength and strength, but cows grow so strong by eating plants. Why not be alone?
This is mainly because the digestive system of herbivores such as cattle is completely different from ours and much stronger than ours. For example, they have four stomachs and a large number of microorganisms in the rumen. These microorganisms will help the host absorb the nutrients in plants more thoroughly through decomposition and fermentation, which is not possible for carnivores. Moreover, herbivores eat an amazing amount. Their strong bodies are obtained through constant eating. Let's recall that when we watch programs like Animal World, herbivores are almost either eating or on the way to find food. The eating behavior of herbivores can be said to be a relatively standard "quality is not enough, quantity is enough".
But we humans don't have the appetite of herbivores. For example, if we want to eat tofu to get enough methionine, then the amount of food we eat may become very huge, which is difficult for ordinary people to bear. And even if you can bear it, the intake of other amino acids and carbohydrates has already exceeded the standard, which is why although the protein content of tofu is very good, people who exercise mainly choose eggs and chicken breast.
So finally, to sum up: Tofu is a very delicious food, a great food invention, and a well-deserved high-protein food among all plant foods. But the premise of all this is "compared with other plant foods". Once compared with eggs, meat and dairy products with natural advantages, the nutritional structure of tofu is still at a disadvantage.