«RABBIT STARVATION»: Can protein excess be dangerous?

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Recently, a real frenzy has arisen around protein diets. People have begun to care about protein in their diets more than ever before in history. Social media is full of calls to consume more protein, including through supplements such as protein shakes. Food companies have also started highlighting protein content on product packaging to boost sales. But let us try to figure out which protein sources are actually beneficial for us and how much protein we really need.

PROTEIN INTAKE GUIDELINES

egardless of whether you want to build muscle mass, improve your physical fitness, or manage your weight, everyone — from fitness influencers to doctors — seems to agree that we need more protein. Protein does indeed play an important role in maintaining muscle mass and overall health. But is it possible that, in our enthusiasm for protein, we have gone too far? Recommendations for protein intake vary. A common guideline suggests consuming about 0.75 g of protein per kilogram of body weight per day. However, many consider this amount too low and argue for 1.2–1.6 g of protein per kilogram of body weight. Some social media «gurus» even talk about 3 g. So who is right?

MORE DOES NOT MEAN BETTER

There is no simple, definitive answer, because the amount of protein we need actually changes depending on the condition of the body. For example, athletes and people recovering from illness should consume more protein. To counter age-related muscle loss, older adults need at least 1.2 g of protein per kilogram of body weight. But in general, it is worth remembering that the body absorbs only a small portion of the protein we consume. This means that the rule «the more protein, the better» does not work.

LESS, BUT MORE OFTEN

In fact, it is not the amount of protein that matters most, but the quality and frequency of its intake. Ideally, one should aim to eat small portions of protein-rich foods more frequently throughout the day. Current evidence suggests that consuming 20–30 g of protein (roughly the equivalent of a handful) at each meal is optimal for maintaining muscle mass and improving physical performance. So what are the ideal sources of protein for us? First and foremost, natural whole foods — nuts, seeds, milk, eggs, legumes, as well as meat and fish.

A DEFICIENCY OF FIBER, NOT PROTEIN

Unfortunately, we do not live in an ideal world. So let us agree that protein-enriched products from supermarkets can also be useful. However, it is important to consume them in moderation. One should not forget that they typically contain a lot of sugar and belong to the category of ultra-processed foods, meaning they include ingredients you would not normally find in your kitchen. The combination of these two factors can be harmful to your health. Moreover, despite their high protein content, ultra-processed foods may lack other essential components of a healthy diet — fiber, vitamins, and minerals. It is worth recalling that in the modern diet it is not protein deficiency, but precisely fiber deficiency, that is one of the main factors contributing to the deterioration of public health.

MUSCLE MASS DOES NOT DEPEND ON THE AMOUNT OF FOOD

Doctors recommend that no more than 15–25% of our daily energy intake should come from protein. This equals about 76 g per day for a healthy adult man weighing 90 kg, or 53 g per day for a healthy adult woman weighing 70 kg. For a hypothetical 90-kilogram athlete aiming to build muscle mass through strength training, intake may be increased to 144 g per day. However, studies show that consuming larger amounts of food provides no additional benefits for muscle growth. Simply because the body’s capacity to build muscle tissue is limited. Therefore, consuming protein beyond the recommended amount offers no real benefit.

«RABBIT STARVATION»

Excess protein is eliminated from the body quite efficiently. However, it can still cause certain problems. The more protein we consume, the more energy we obtain. Any surplus energy is converted into fat tissue, which can be unhealthy in the presence of certain conditions. For example, people with chronic kidney disease should carefully monitor their intake and avoid excessive protein consumption. Medicine is familiar with a phenomenon now referred to as protein poisoning. It occurs when you eat too much protein while not getting enough fats, carbohydrates, and other nutrients. An early 20th-century researcher, Vilhjalmur Stefansson, gave this phenomenon the name «rabbit starvation». He discovered that people who subsisted mainly on rabbits (whose meat, as is well known, is very lean) fell ill quickly.

THE KEY IS NOT PROTEIN, BUT ITS SOURCE

«Rabbit starvation» serves as an important reminder that the source from which our bodies obtain protein is far from irrelevant. Australian scientists have found that excessive consumption of animal-based protein by older adults is associated with an increased risk of death, especially from diabetes and cancer. To reduce this risk, dietary patterns need to shift toward a greater emphasis on plant-based sources. This is important for two reasons. Plant-based protein sources contain dietary fibre, which most people today lack — something that leads to heart and intestinal problems. They also contain far lower amounts of saturated fats, which increase the risk of cardiovascular disease, compared to animal protein sources.

PROTEIN IS NOT A PANACEA — BALANCE MATTERS

Of course, everything said above is not a reason to completely give up animal protein. Medical experts insist that maintaining a balance between animal and plant sources is far more important than simply trying to add more of one type of protein to your diet. Proteins, fats, carbohydrates, vitamins, and minerals — none of these are superfluous; they all work together and are equally important for the body. To keep it functioning smoothly, people simply need to maintain the right proportions. And under no circumstances should one think that any single component — protein, for example — is a panacea.

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