Muscle growth and protein: the essentials

Muscle growth needs two simple things: a strong training stimulus and enough food at the right times. In this article we look at why protein, an energy surplus and meal frequency determine whether your body leans toward building or breaking down muscle.

Why does muscle growth depend on how protein is distributed?

When it comes to optimal muscle growth, hitting your daily calorie target is not enough. Your body needs a steady supply of protein, and of energy in general, roughly every three hours, apart from the overnight period. This matters most when your training is hard and the goal is not simply to gain weight but to build muscle mass.

Muscle building requires overeating, meaning you need to take in more energy than your body burns. How much more depends on how fast you want to gain weight. The question is where the extra calories come from: carbohydrates, fat or protein.

The Atkins diet and the Anabolic Diet, created by world championship powerlifter Dr. Mauro DiPasquale, rely heavily on protein and fat. Carbohydrates are limited to just a couple of dozen grams a day. Some of the protein is burned for energy, but because the amount is large, there is still enough left to build muscle. In practice, the weak point of this way of eating is simple: you have to actually eat enough. Protein suppresses appetite, and it is easy to skip a meal.

Honestly, ½-1 liter of cream as a protein snack sounds pretty brutal, but anyone who has been through the Anabolic Diet knows what we are talking about. On the Atkins or Anabolic Diet, the total amount of protein may be sufficient, but in terms of supplying protein evenly, these diets are not always the most convenient. Hunger and the need to eat are not the same thing. Some people find that even a phone alarm helps them remember to eat something proper every three hours.

When you are cutting body fat, protein intake on the Anabolic Diet is generally adequate. During weight loss this is important, because your body needs a signal that it is worth holding on to muscle tissue.

Muscle growth across different diets

On a Zone-type diet, the recommendation is to get 30% of total energy from protein, 30% from fat and 40% from carbohydrates. The protein amount here is quite high. At every meal, getting enough protein should be fairly easy. On the other hand, plenty of protein can again dampen appetite, so you need to keep an eye on how often you eat.

During weight loss, the protein you get on the Zone diet is enough to help protect muscles from breakdown. That does not mean the diet is ideal for everyone, but in terms of protein distribution it is stronger than a menu thrown together at random.

The traditional Western diet is harder for anyone trying to bulk. The usual recommendation of 15-20% protein, 25-30% fat and 60% carbohydrates can push protein into the background. Snacks are where it is easiest to go wrong. A glass of milk and a banana make a nice snack, but they do not always deliver the amount of protein you need.

This kind of eating plan only starts to work better once your intake is above 3000 kcal per day. The higher your total energy, the easier it is to get enough protein. With 3000 kcal, 15-20% protein means 112-150 g of protein per day. For a person weighing 90 kg, that comes to 1.24-1.66 g of protein/kg/day; for someone weighing 100 kg, the relative amount is smaller still.

When you are dieting, this kind of split often works poorly or not at all. When energy intake drops, the share of protein has to go up to avoid cannibalizing muscle. The simple truth: in a calorie deficit, the body is not very generous about holding on to muscle if it does not have an adequate protein supply.

How does protein balance work?

Protein balance is the balance between the protein your body uses and the protein you take in. Your body uses protein all the time, and it has to be replaced through food. Not all the protein broken down in tissues is thrown out of the body; some of it is taken back into internal circulation as amino acids. This internal recycling is not counted toward the protein you get from your daily food, however.

For muscle building, protein balance has to be positive. You need to take in more protein than your body uses up. If hard training provides the growth signal but food does not supply enough building material, the result will be weak.

When estimating protein needs, you also have to take tissue repair into account. Very large tissue damage occurs in fire victims, but in sports terms, marathons, triathlons, ultrarunning and the like also create training load. In bodybuilding, damage results from hard training. It is not usually dramatic, but the body still has to repair it.

Textbook wisdom says that a person is born with a certain number of muscle cells and that this number does not increase over a lifetime. In laboratory animals, however, an overproduction of muscle cells, known as hyperplasia, has long been demonstrated. This could explain some of the peculiarities associated with bodybuilding. If very heavy gym training were to trigger a similar process in humans, it could explain the 3 g of protein per kg of body weight. Who knows, perhaps one day this can be proven more clearly in humans too.

In a chicken’s injured thigh muscle, extensive hyperplasia has been observed during healing. Since no bodybuilder has volunteered to have their muscles deliberately injured, it is not known whether the same happens in humans. The point is nevertheless a practical one: when recovering from tissue damage, we need a steady supply of protein so that protein synthesis can work as well as possible.

Muscle growth, anabolism and catabolism

Nutrition scientists talk about the amino acid pool, a temporary store the body can draw amino acids from when food isn’t supplying enough of them at that moment. The principle holds, but that doesn’t mean the store is endless. When training is hard and your basal metabolism is running at high revs, you need to take care to keep your protein supply constant.

The amino acid pool is certainly important for vegetarians. It used to be said a lot that to get all the essential amino acids you had to combine legumes with grains at every meal. That talk has faded, because amino acid turnover spread across the day helps to even out any shortfalls. But the pool is still only a temporary store. If it isn’t replenished, it empties quickly.

Anabolism and catabolism are familiar words to any gym-goer. In anabolism, cells grow in size; in catabolism, they shrink. Catabolism is often linked to illness. Bedridden patients recovering from major surgery can lose 20-30% of their muscle mass in just one month. That is a serious catabolic state.

Catabolism happens to all of us every day, and our state can change several times over the course of a day. Ideally, the body would spend most of its time in an anabolic, or building, state. Heavy strength training, overtraining and a calorie-deficit diet are examples of situations where the body may shift in a catabolic direction. The body enters an anabolic state when, for example, it has received a growth stimulus from hard training or from eating well above maintenance.

Some sports supplements have an anti-catabolic effect. This means a product may help prevent the body from slipping into a catabolic state, or help it get out of one. Anabolic steroids are also called anti-catabolic for this reason. The practical message of this article is simpler, though: you need to get enough protein, and get it evenly, so that your body is in a building phase most of the time.

Practical protein and meal distribution

Nitrogen balance is one way of looking at the state of the body. Proteins and amino acids are the only carriers of nitrogen into the body. When more nitrogen enters the body than leaves it in urine and feces, the body is in an anabolic, or growth, state. In the opposite case, catabolism prevails. Nitrogen balance is easier to keep under control if you spread your protein intake evenly.

How often should you eat protein? The answer is a practical one: often enough to keep the body in an anabolic state as much as possible. For strength training, the rule of thumb is 5-7 times a day. That doesn’t have to mean seven big cooked meals. Sometimes a meal is simply a smaller, protein-rich snack.

Which protein should you choose? If you take the amino acid pool into account, the quality of the protein in any single meal matters less. If at some point your food doesn’t supply quite all the amino acids, the shortfall is taken from the pool. Over the course of a day, however, the amount of high-quality protein still counts. For a trainee eating normal food, it is hard to go completely wrong when the menu includes meat, fish, dairy products, soy, whey protein and so on.

The last detail is absorption speed. Free amino acids are absorbed quickly, and their effect on, for example, nitrogen balance is short-lived, under an hour. Hydrolyzed protein is broken down and absorbed in about ½-1 hour, whey protein in roughly 1-2 ½ hours, and casein and other protein powders in 3-4 hours. These figures are not absolute, because absorption is affected by the whole meal, by digestion and by the individual person.

Protein dose per meal when eating 6 times a day, by body weight category and protein amount
6 meals	1.4 g/kg/day	1.6 g/kg/day	1.8 g/kg/day	2.0 g/kg/day
70 kg	16 g	19 g	21 g	23 g
80 kg	19 g	21 g	24 g	27 g
90 kg	21 g	24 g	27 g	30 g
100 kg	23 g	27 g	30 g	33 g
110 kg	26 g	29 g	33 g	37 g
120 kg	28 g	32 g	36 g	40 g

Anabolic Diet 60% protein, 35% fat, 5% carbohydrates
	2500 kcal	3000 kcal	3500 kcal	4000 kcal
Protein/day	375 g	450 g	525 g	600 g
Protein split into 6	63 g	75 g	88 g	100 g

Zone 30% protein, 30% fat, 40% carbohydrates
	2500 kcal	3000 kcal	3500 kcal	4000 kcal
Protein/day	188 g	225 g	263 g	300 g
Protein split into 6	31 g	38 g	44 g	50 g

Traditional 20% protein, 25% fat, 55% carbohydrates
	2500 kcal	3000 kcal	3500 kcal	4000 kcal
Protein/day	125 g	150 g	175 g	200 g
Protein split into 6	21 g	25 g	29 g	33 g

FAQ

Does muscle growth always require a calorie surplus?

Usually, yes. Muscle building is easier when you take in more energy than you burn. A beginner or someone returning after a long break can sometimes progress on a smaller surplus, but for experienced lifters, getting enough energy is very important.

Do you have to eat protein exactly every three hours?

You don’t need to count the minutes. The point is to spread your protein intake evenly across the day rather than leaving most of it for one late meal. With strength training, eating 5-7 times a day works well for many people.

Is fast protein always better than slow protein?

Not always. Free amino acids and whey protein act faster, but casein and other slower sources can help supply amino acids for longer. What matters is the daily total and a suitable distribution, not singing the praises of a single source.

Author: Greta

Source: Protein

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