Eating too much protein: is it advisable?

Health information and advice everywhere can make one a bit dizzy concerning what are considered the right food choices to make. We know the value of protein well, but not necessarily in detail. Some questions remain: should we eat a lot of protein? What are the recommended daily allowances? Which categories should be given priority? What impact does protein have on our health? Please read on if you would like to find out.

Amino acids: some basic facts!

As an introduction, remember that protein is made up of large molecules, which in turn, are made up of chains of amino acids. There are twenty amino acids, nine of which are essential, as they cannot be made by the body. As a result, they must come from food. The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Eating them every day gives us energy; however, their primary purpose is elsewhere: they provide amino acids after digestion for the production of protein for the body itself, for the cellular infrastructure, tissues, organs, hormones, enzymes, neurotransmitters, etc. They are “bricks” on which we depend to function and that is why they are essential. They are not stored; we therefore have very few reserves. We have to replenish them every day and food is the only way to do that.

The quality is also important, and the complete presence or absence of those essential amino acids is dependent on quality. Foods that contain all nine essential amino acids are called complete proteins. The greater the proportion of those foods in your diet, the higher its nutritional quality will be. Eggs are the gold standard of protein in terms of quality because they contain all 9 essential amino acids. When an amino acid is missing, the whole protein balance is threatened, and in particular the proper use of other (non-essential) amino acids.

To understand whether or not we need to eat a lot of protein, know beforehand that two categories are distinguished, those of animal origin (meat, egg, dairy products and fish) and those of vegetable origin (legumes, grains, seeds and algae or seaweeds). However, they are not of equivalent value. Again, foods that contain all nine essential amino acids are called complete proteins and include beef, poultry, fish, eggs, dairy, soy, quinoa and buckwheat. Foods that contain some but not all the essential amino acids are called incomplete proteins and include nuts, seeds, beans and some grains. This is why it is recommended that vegetarians and vegans combine legumes and whole grains to obtain the 9 essential amino acids. Exceptions to the rule: Pseudo-grains like quinoa, amaranth and buckwheat which are actually seeds and just like regular grains have similar overall nutrient compositions, but they are also a great source of fibre and minerals. In addition, they have an exceptional balance of amino acids, with higher content of lysine, methionine and cysteine than common cereals often deficient in lysine, threonine or tryptophan((Motta et al., 2019).

Daily protein intake

Our needs are around 0.8g/kg of body weight each day, or 48g for a 60kg person. This corresponds to approximately 200 to 250 g of protein foods. In certain circumstances, the needs are stronger, such as during childhood growth and development, pregnancy, breastfeeding or in the event of intense and prolonged physical effort. To give you an idea, 100g of red meat provide about 25g of protein, 100g of fish 20g and 100g of cooked lentils 10g. The important thing is to vary the sources for diversity (which is always beneficial) and to balance the intake throughout the day to avoid deficiencies. Generally speaking, the rule is to eat one protein at every meal. For example, an egg in the morning, another animal protein at noon and a vegetable protein in the evening. If you do not wish to consume meat, it is recommended to diversify the sources of your vegetable proteins on a daily basis to have all the essential amino acids, which are found in animal forms.

The benefit of eating protein in the morning

Breakfast is the first meal of the day, therefore it is important to pay attention to it as it will have an impact on the rest of the day. High carbohydrate breakfasts are deeply rooted in our culture (toasted bread, jam or marmalade, pastries, highly processed cereals depleted of nutrients, orange juice, etc.) yet they are far from perfect as they do not provide enough nourishment, are acidifying and often cause hypoglycaemia (tiring our pancreas) as well as food cravings.

To stay healthy, change your habits by eating savoury rather than sweet and include proteins. You can for example eat eggs (as little cooked as possible), goat or sheep cheese or even a slice of smoked salmon. You will be more satiated, won’t feel the need to snack mid-morning due to energy crashes and will more easily meet your daily protein needs. In addition, amino acids are precursors of neurotransmitters (serotonin, dopamine, noradrenaline, etc.), which participate in the transmission of nerve impulses. By ingesting protein in the morning, you promote their release early in the day and support your brain activity.

Eating lots of protein: what are the limits?

As you now understand, we cannot live without protein. However, overeating protein (beyond what is recommended above) can be harmful too. Indeed, the digestion of these lead to the production of uric acid (resulting from the degradation of purines). It is very difficult for us to eliminate it (only 2%) because humans and higher primates are unique in that they lack uricase, the enzyme capable of oxidizing uric acid. As a consequence of this enzyme deficiency, humans have high serum uric acid levels. Red meat, offal and cold meats are the most toxic from this point of view due to a high level of uric acid; other proteins contain less. In case of build-up in the body, this acid becomes toxic. The body becomes acidic, which contributes to acid-based imbalance. For example, a gout attack can occur, as a result of protein overconsumption.

The notion of excess is obviously to be individualized, according to the metabolic capacities of each. As the digestion and elimination of proteins involves the liver and to a lesser extent the kidneys, if these organs are weakened, purines are insufficiently eliminated, which increases uric acid. If you need to eat a lot of protein, it is better to have good liver and kidney functions, otherwise, you risk storing these toxins. In this regard, hydration is essential to evacuate waste through the kidneys, hence the need to drink at least 1.5 litres of water a day.

The impact of protein on health has been studied by scientists in different ways, including through the protein restriction diet. What should be noted is that reducing its intake helps prevent the onset of diseases related to aging and therefore increases life expectancy.

It is not a question of reducing your protein intake but rather optimizing the quality. There is a balance to be found between overeating protein and not eating enough to protect your health. Deficiencies are not desirable, as you can imagine. What you have to aim for is quality: without switching to veganism (a diet without any animal products), introducing more plants to your meals is a good way to support your health, ideally up to 50% more every day. As for animal products, do not forget to eat fish, which is much more digestible than meat.

You now know more about the risks of eating too much protein; as the Swiss physician Paracelsus proclaimed in the 16th century “All things are poison and nothing is without poison; only the dose makes a thing not a poison.”. This key message lends itself perfectly well to the consumption of protein, which must remain varied, qualitative and without excess!

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