A completely meat-free diet can lead to serious nutritional deficiencies. Let’s summarise the risks of an exclusively “plant-based” diet.

Nowadays, we hear a lot about the risks of eating too much, with meat too often in the crosshairs and other foods left out, like hyper-processed foods, which deserve more attention. But we never talk about the risks of a completely meat-free diet. What happens if we don’t eat it? Can we really do without it?

Because of its unparalleled ability to fully satisfy all human nutritional needs, meat can be defined as a species-specific human food. Our ancestors were carnivorous super-predators, and our physiology proves that we are perfectly adapted to eating and digesting meat and effectively absorbing all its valuable nutrients.

No meat, risk of shortages

Meat has been practically part of our diet since humans first walked the earth and has contributed to its evolution. It has been shown that without meat, our brains would be significantly smaller, and our intelligence would not be as developed as it is today. Eliminating meat would mean giving up a unique food full of essential nutrients and, therefore, very difficult, if not impossible, to replace.

For this reason, those who do not eat meat must balance their diet by increasing their intake of other foods, sometimes with the help of supplements for the nutrients found only in meat, to fill the many gaps. Maintaining a balanced diet without food as efficient as meat is not an easy task and the risk of developing deficiencies that are harmful to health is high, leading in the long term to the development of serious pathologies.

One of the main conditions that can occur is a lack of complete proteins, i.e. essential amino acids, of which meat is the main source. Nowadays, it seems difficult to suffer from a protein deficiency, but it is more common than we think. Inadequate protein intake can lead to loss of muscle mass, or sarcopenia, which is now affecting young people, fatigue, general weakness and a reduction in immune defences.

Iron and anaemia

Another example is iron, which is found in meat in the heme form, which is easier for our bodies to absorb and use than the non-heme iron found in vegetables. A diet without meat, especially red meat and offal, can lead to iron deficiency anaemia, characterised by fatigue, pallor and weakness. Eating meat less than once a week is one of the main risk factors for anaemia during pregnancy. This condition should be avoided to ensure that everything goes well during this critical period.

Megaloblastic anaemia is another form of anaemia caused by a deficiency of vitamin B12, which is found in its biologically active form only in meat and animal products. The bioavailability of vitamin B12 is greater in meat, especially red meat, mutton and chicken, than in other animal foods such as fish or eggs. A deficiency of this vitamin can lead to irreversible neurological damage, especially in children, including nerve damage, mental confusion, memory loss, cognitive disorders and dementia. This is why vegetarians, and especially vegans, need to take this vitamin through supplements or fortified foods.

The Importance of Zinc, Calcium and Vitamin D

Zinc is also found in high levels and bioavailability in meat, especially red meat and offal. A deficiency can affect the immune system, delay wound healing and reduce fertility in couples. Interestingly, the presence of muscle tissue in the meal increases the absorption of zinc and iron from vegetables, giving meat this power, which is called the meat factor. Osteoporosis, brittle bones and an increased risk of fractures are other conditions that can be caused by a lack of calcium and vitamin D, which are highly bioavailable in meat and whose consumption has been shown to be a strategy for preventing osteoporosis in the elderly and in post-menopausal women. Regular meat eaters have also been shown to have a lower risk of hip fracture than vegetarians and pescetarians.

EPA, DHA and antioxidants

The absence of meat can also lead to a deficiency of long-chain omega-3 fatty acids such as EPA and DHA, essential fats for which meat, especially chicken, is now a reliable and preferred source, especially for those who do not like fatty fish. The lack of EPA and DHA has a negative impact on cardiovascular and brain health, leading to an increased risk of heart disease and cognitive decline. The lack of nutrients, of which meat is the best source in terms of quantity and bioavailability, can also negatively affect thyroid function, with hypothyroidism, weight gain, depression, mood disorders and an increased risk of eating disorders.

To reduce the risk of these conditions, it is essential that those following a meatless diet carefully plan their intake of critical nutrients, using other animal sources and taking supplements where necessary. Recently, increasingly sophisticated detection techniques have made it possible to identify other previously unknown compounds in meat, such as powerful meat-specific antioxidants and substances with anti-cancer potential, such as trans-vaccenic acid.

In short, the complexity of meat’s structure and composition makes it a unique food. No matter how hard you try to replace it, a ‘plant-based’ diet will never be the same. The wisest choice is not to give up such precious food but to benefit from its incomparable properties, even in small quantities.