Circulation myths circulating in clubs say that there is only a strictly defined amount of protein that can be assimilated in a single portion. Usually, 30 g of protein is given in a portion, while the protein above this value is to be oxidized for energy purposes or to be transaminated with the formation of urea and other organic acids. This would be true for the supply of high-quality, fast-digestible proteins without additives (eg fats).
Providing a protein with slower kinetics, especially in combination with fats, delays absorption, and thus may increase the use of essential amino acids. In the case of an ordinary chicken egg, 60 g (medium egg) contains 7.5 g of protein, 0.36 g of carbohydrates and 5.82 g of fat. In 50 g boiled eggs we find 6.3 g of protein, 1 g of carbohydrates and 5 g of fat.
The egg has a speed of protein absorption estimated at 3 g per hour, therefore full absorption of the omelette containing 20 g of protein will take ~ 7 h.
Macnaughton et al. Randomly assigned men and given 20 or 40 g of protein, in two trials separated by 2 weeks. During one study participants received 20 g of whey protein immediately after strength training. In the second attempt, they received 40 g of protein. The synthesis of myofibrillar (muscle) proteins was 20% higher with 40 g of protein. From other scientific research we know that even a poorly trained (internship about a year), a fairly light man (72-82 kg, with an increase of 168-190 cm) can consume 36 g of whey protein (whey protein isolate) after the resistance training, as well as almost 50 g rice protein (RPI).
The amount of protein that is absorbed in one portion depends on its type, kinetics, and the time of absorption depends on whether the proteins are accompanied by, for example, fats. For the absorption of protein, the amount of dry body weight is also important. The heavier a person is, the greater the need for amino acid supply shows. Proteins that are slowly absorbed (eg proteins from boiled eggs or casein) show different properties than those that are easily digestible (eg isolate or whey protein hydrolyzate).
For example, whey protein isolate causes the maximum concentration of amino acids after 69 ± 3 minutes, while the rice protein isolate after 93 ± 4 min. Casein works much longer compared to isolate, hydrolyzate or whey protein concentrate. These last proteins are better suited as an addition to a meal during the day or as an additional portion of building material after resistance training. The role of the isolate ends after about 3.5 hours after eating a portion of 22.6 g of protein, micellar casein works even after 6 hours from serving 23.2 g portion (energy 993 kJ). 8 Therefore, slow-leaven proteins are a better solution, eg at night.
You can read also: Protein, protein, how much should we consume per day?