Protein for athletes: how much you need and how to spread it out

What is protein for if you do sport?

Protein provides the amino acids that muscles use to repair themselves and adapt to the demands you place on them. Every demanding workout causes a little damage to muscle tissue. Protein from subsequent meals rebuilds it. Protein also forms enzymes, hormones and antibodies.

It contributes little as fuel. To move, the body relies mainly on carbohydrates and fat, and reserves protein for building. That is why eating more protein does not give you more energy during a session. The guide to sports nutrition explains what to eat to perform, compete and recover.

How much protein does an athlete need, depending on their sport?

This is the question most often asked in consultations by people who are starting to train seriously. For the adult population in general, the reference intake is about 0.83 g per kilogram of body weight per day [3]. If you train, it increases.

The consensus of sports medicine and dietetics associations in the United States and Canada puts it at between 1.2 and 2 g per kilogram per day [1]. Another sports nutrition expert position gives a similar range of 1.4 to 2 g for most people who exercise [2].

These ranges apply to both strength and endurance training. There is no separate figure for runners and people who lift weights. The point within the range depends on how much you train, what you are aiming for and whether you are eating less energy than you expend .

In grams, at 60 kg the range is 72 to 120 g per day, and at 80 kg it is 96 to 160 g [1].

If you do light exercise two or three times a week, your usual diet will generally already cover what you need . For adolescents who compete, a professional adjusts the amount while taking their growth into account .

How to spread it throughout the day

In addition to the total amount, distribution matters. Muscles make better use of protein when it is taken in moderate, spread-out portions than in one very large meal [2]. The recommendation is about 0.25 to 0.3 g per kilogram at each eating occasion, which works out to 20 to 40 g depending on your body weight [2] [1].

It is a good idea to space these portions about three or four hours apart [2]. In practice, you can spread them across breakfast, lunch, an afternoon snack and dinner, depending on your day. Include breakfast unless it does not agree with you or does not fit your lifestyle.

Four servings containing some protein, spread throughout the day, matter more than one large plate of meat at night.

After training, have one of these servings [1]. You do not need to eat anything special in the changing room. If you have lunch or dinner within the following two hours, that meal already does the job .

Before bed, 30 to 40 g of slowly digested protein increases muscle formation during the night [2]. Studies use milk protein. In the kitchen, the closest options are whipped fresh cheese or cottage cheese, and a complete late dinner already serves this purpose .

Which foods provide the most protein per serving?

The foods with the most protein per serving are meat, fish, eggs, dairy products, legumes and soy. The table gives rounded figures for typical servings, based on the Spanish food composition database [4].

Food and serving	Approximate protein
Chicken or turkey breast, 120 g raw	about 26 g
White fish, such as hake, 150 g	about 20 g
Tuna in water, one 80 g can, drained	about 20 g
Eggs, two medium	about 13 g
Fresh cheese, 100 g	about 12 g
Milk, one 250 ml glass	about 8 g
Plain yogurt, one 125 g pot	about 5 g
Lentils, 70 g dry	about 16 g
Chickpeas, 70 g dry	about 14 g
Soy drink, one 250 ml glass	about 8 g
Almonds or peanuts, 30 g	about 6 g
Pasta, 70 g dry	about 8 g
Wholemeal bread, 60 g	about 5 g

Bread, pasta and rice provide less per serving, but they are eaten daily and add up. A plate of lentils, an omelette sandwich and a glass of milk already provide more than 40 g [4].

If you want to check a food that is not in the table, the Spanish food composition database is free and publicly available.

If you are vegetarian or vegan

With a well-planned vegetarian or vegan diet, you can perform well and gain muscle. Plant protein is somewhat less digestible. It also tends to contain lower amounts of some essential amino acids, which the body cannot make [5]. See “Pea protein”.

For this reason, vegan athletes are advised to aim for the upper end of the range, 1.7 to 2 g per kilogram per day [5].

Amino acid intake is complemented by varying legumes, soy, grains, nuts and seeds throughout the day . You do not need to combine them in the same meal, although the classic lentils with rice already do that. If you have milk or eggs, it is easier to meet the target.

As a milk substitute, the best option is a soy drink with at least 3% protein, as shown on the label. Bear in mind that soy is an allergen.

Does eating a lot of protein damage the kidneys?

In healthy people, the data do not show kidney damage. A review of the available studies found no differences in kidney function between people who ate more protein and those who ate less [6]. The European Food Safety Authority considers amounts of up to twice the reference intake safe for adults, about 1.7 g per kilogram per day [3].

With chronic kidney disease, the amount changes. Kidney disease guidelines adjust protein intake according to the stage of the disease [7]. They also take the risk of progression into account [7].

If you have kidney disease or a test shows that your kidney function is reduced, your nephrologist or dietitian will tell you how much protein, potassium, phosphorus and other ions and minerals are suitable for you based on your stage . The guidance is in the chronic kidney disease diet.

More protein is not always better. Beyond this range, it tends to displace carbohydrates and vegetables from your plate, even though you also need them for training .

What mistakes do we see in consultations?

• All your protein at dinner. Coffee and biscuits in the morning, then a large steak at night.
• Counting only meat. Legumes, dairy products and bread also add to your intake.
• Increasing protein and cutting carbohydrates. In endurance sports, you notice it in your legs straight away.
• Not eating enough overall. If you do not get enough energy, the body cuts back on functions and performance drops, regardless of how much protein you eat [8].

Almost always, the gap in protein intake we find in consultations is at breakfast.

When is food not enough?

In most cases, food is enough [2]. It can be harder to meet your needs with a heavy training load, low appetite, travel and competitions, or a vegan diet with high requirements .

In these situations, review your meal distribution with a dietitian . If a supplement is being considered, your doctor or dietitian should prescribe it. If you are a minor, do not take sports supplements.