Protein is everywhere these days. Every day we find more and more products in supermarkets that are enriched with extra protein and, of course, at an extra price, but why taking protein?
In general, it is good news that public awareness of the need to get enough protein is increasing, but it may also be necessary to clarify some concepts in order to maintain healthy levels and not to expect miracles from protein.
Why is it so important to get enough protein?
Within the family of macronutrients, i.e. nutrients that provide us with energy, protein is the only one of which our body needs a certain amount; no more and no less. Protein is the “brick” that we need to repair and build our muscle mass. What protein gives us, we can’t get from any other source, whereas we have some of flexibility to get energy from carbohydrates or fats.
What happens if I don’t get enough protein?
When we do not take in enough protein, our body is not able to maintain our muscle mass. If the protein deficit is prolonged, we will progressively lose muscle. This process, called sarcopenia, is often blamed on age, but this is not true. As we can see in the image, there is no great difference in the musculature of a 70-year-old triathlete and a 40-year-old triathlete, while the image of a 70-year-old sedentary person shows a much smaller amount of muscle and a much greater amount of fat. Not using muscle and not taking in enough protein is what leads to muscle loss, not age.
Let’s look at the following example. An active 70 kg person would need about 1820 Cal per day, 480 of which should be protein (120 grams, or 1.7 grams per kilogram of body weight). However, instead of the 120 grams needed, this person takes only 60 grams, and instead of getting 1340 Cal from carbohydrates and fats, he gets 1580 Cal (240 Cal more than he needs). This excess of carbohydrates and fats accumulates in the form of adipose tissue, while the protein deficit will cause us to progressively lose muscle, although this change is not reflected on the scales, as the calorie balance remains neutral. In other words, we will remain at the same weight, but our body composition will get worse year after year.
How much protein should we eat per day?
The WHO establishes a minimum of 0.8 grams per kilo of body weight per day. However, different studies, such as this one, presented in 2015 at the Canadian Nutrition Society conference, show that protein intakes well above this recommendation, between 1.2 and 1.6 grams per kilo, are preferable to prevent muscle loss in adults.
In the case of people engaged in intense physical activity, studies such as this one, published in the International Journal of Sports Science, recommend a somewhat higher protein range (1.4 g – 1.8 g), and even higher (1.8 g – 2.0 g) in the case of being in a calorie deficit.
This other study, published by the International Society of Sports Nutrition, goes up to 3.0 g for people who train intensively when they are in a calorie deficit.
Would taking in more protein be beneficial?
In terms of maximising muscle preservation and/or muscle building, scientific evidence shows that more is not better. If you want to gain muscle, ideally you should have a slight calorie surplus (about 200-300 calories more than you need). This surplus will create the optimal hormonal environment for muscle protein synthesis and in this environment, exceeding the above recommendation (1.4g – 1.8g) has not been shown to result in greater muscle gains.
In periods of calorie deficit it is recommended to slightly increase protein intake, but a very high intake sustained over time could lead to various health problems.
How to consume protein?
To consume the protein we need, we have two ways: through real food (meat, milk, eggs, fish, pulses, nuts…) or through supplements (shakes, yoghurts and protein bars).
There is no one way that is better than the other; choose what suits you best and what fits your lifestyle. Protein supplements are very safe and have been used for many years. They offer you the possibility to supplement your daily intake if you find it difficult or uncomfortable to do so with real food (it’s always more convenient to have a chocolate shake for breakfast than three chicken breast fillets).
It is best to spread your total intake over several meals throughout the day to maximize assimilation, as we can see in this study published in the Journal of Sports Science.
When is it best to take protein?
In general, there is no one best time to take protein. Muscle protein synthesis is a process that remains active for up to 48 hours after training, so the popular belief that we should take protein as close to exercise as possible has little scientific basis.
As we said earlier, it is best to spread our intake over the course of the day in several intakes.
There is one small exception to this rule, and that is supplementing with casein (one of the proteins in milk) just before bedtime. As we see in this study by the International Society of Sports Nutrition, supplementing with 30-40 grams of casein before bedtime provides an increase in muscle protein synthesis, as well as a certain increase in metabolic rate.