Outside of the debate that exists about whether eating eggs is bad for your health (which we already say no), it is interesting to know why the fitness world has decided that it is better to consume egg whites than whole eggs. Does muscle growth increase us? Isn't it better to take yolk eggs to increase nutrients?
If you are a regular at the gym or training with company, you will have been told about the importance of post- workout food. Which must contain to a greater extent proteins and fast digestion hydrates , but very little fat.
This type of food is recommended to contain these characteristics so that amino acids enter the blood much faster, increase protein synthesis and produce muscle growth . Fat is a nutrient that takes longer to digest, so it doesn't usually give it a great post-workout role.
But the obsession with segmenting nutrients can make us fall into error. They are not only fats, hydrates or proteins, there are many micronutrients necessary for a good recovery. That is, if we avoid fat after training, it could be counterproductive.
What happens to whole eggs? Why is there a suspicion? Many people think of eggs as a source of protein based on the whites, so they discard the yolks without regret.
Instead, the University of Toronto has conducted a study to determine if whole eggs are better than clear eggs for muscle growth.
How does the study was realized?
There were 10 young people, about 21 years old, who underwent this investigation. They had to do a leg workout that consisted of 4 sets of extensions and presses with 10 repetitions each.
Then the ten boys were divided into two groups:
- Group 1: ate 3 whole eggs post-workout
- Group 2: they ate an amount equivalent to 18g of protein from egg whites, post-workout as well.
And with the divided volunteers, they made several methods to know how "anabolic" both meals were:
- They mixed the eggs with compounds called " isotope tracers ." These allowed us to see how much protein from the eggs went directly to the muscle tissue, compared to the other organs.
- They measured how quickly each meal influenced leucine levels, and how long they remained elevated after each meal. Leucine is a primary amino acid in protein synthesis, and foods that maintain a high blood level are considered better for muscle growth.
- They punctured their legs to remove a small piece of muscle tissue. They then examined them to directly measure how protein synthesis was influencing muscle fibers.
The scientists were running tests for 5 hours after finishing the training. All the youngsters who ate whole eggs the first time went on to eat egg whites a second time, and vice versa. Thus a result based on the mean was not given, but in a more specific way by crossing data.
What did they conclude?
In the graph on the left you can see how much protein synthesis was happening in the muscle fibers. Protein synthesis levels increase in many organs of the body after eating, but in this case we wanted to know if they increased or not.
In the one on the right we can see that the protein synthesis in the body was more or less the same in both groups. But, if you look at muscle protein synthesis, people who ate whole eggs had 42% more protein synthesis than people who only took egg whites.
Actually, the scientists themselves were surprised with the result and do not know how to give an explanation for sure. Still, they discussed what the causes may be:
The extra calories from whole eggs will increase protein synthesis.
Egg whites contain 73 calories, compared to 226 for whole eggs. Curiously, eating more calories keeps protein synthesis high, although this is surely not the main reason.
A similar study found that drinking the same amount of calories from whole milk as skimmed milk caused a greater increase in protein synthesis, despite eating less protein.
It is true that calories matter, but the number that we eat in a single meal is not as important as its intake throughout the day when we try to build muscle.
The cholesterol content of the yolks increases protein synthesis
There are studies that show that people who consume more cholesterol develop more muscle than those who consume less. Cholesterol influences the production of testosterone and other anabolic hormones, so it stands to reason that it is part of that difference against the odds.
Some of the bud compounds affect gene expression
Egg yolks also contain micronutrients such as vitamins, minerals, and unique fatty acids, which can promote muscle growth.
There was a study that showed that both whole eggs and yolks caused changes in genes related to muscle growth.
So are whole eggs better for muscle growth?
At first glance we could say yes, but short-term levels of protein synthesis do not translate into increased long-term muscle growth.
This study shows that you don't need to make a low-fat post-workout meal. Leucine levels increased slightly after eating egg whites, so egg whites were digested a little faster, but that doesn't mean there was more protein synthesis.
