THE IMPORTANCE OF PROTEIN
The importance of protein cannot be overstated. It’s not just the domain of the bodybuilder; protein is involved in virtually every cell function. We need it for immunity, detoxification, hormone balance, brain function, gut function, sleep and much more. It’s the key component of hair and nails; a vital building block of muscles, skin, bones and cartilage; essential to the building and repair of tissues, and involved in the production of enzymes and hormones. Furthermore, unlike carbohydrates and fats, our bodies cannot efficiently store protein. So it’s easy to see why we need to ensure adequate and regular supply in our diets. A shortage can lead to many health issues.
Human proteins are built from 20 amino acids. Of these, 9 are essential amino acids, meaning that our bodies cannot synethesise them directly. These 9 amino acids must come from our diet and an inadequate intake of these can lead to deficiencies which in turn can cause low energy, poor concentration, sugar cravings, thyroid problems, hormonal issues, skin complaints, anxiety, poor sleep, inability to lose weight or inability to add muscle.
How much is enough?
The official advice for adults is 0.75g of protein per kg bodyweight per day. So someone who weighs 60kg needs 45g of protein a day, and someone who weighs 70kg needs 53g of protein a day. But this doesn’t account for exercise, and weight training in particular. Studies examining the increased protein requirements of those involved in strength training have suggested that the protein intake may need to be significantly higher, with 1.7-1.8g per kg a commonly (but not unanimously) suggested range.
Can we eat too much?
So it seems reasonable for someone who works out regularly to aim for this higher range. Some may go further still and simply employ the “more is better” motto. But it’s not that straightforward.
Firstly, there is the question of how much protein you can absorb in a single meal. The historical consensus has been around 30g. Although this is increasingly being challenged as an overly simplistic “rule”, it seems a reasonable assumption that our bodies can use only a certain level of protein efficiently at any one time. Processing excess protein can put strain on our digestive system, liver and kidneys. It also leads to elevated levels of ammonia in the body, the long-term implications of which are not yet clear.
The source of protein also has to be considered. If a large proportion of our protein intake comes from meat, we risk upsetting the pH balance of our bodies due to the acidity of animal protein, as well as potentially increasing our saturated fat intake. If a large proportion comes from processed meats, we could increase our salt intake and chemical load. If a large proportion comes from oily fish, our exposure to mercury potentially rises.
So we all need to ensure that we get enough protein for our individual needs, but not blindly consume a lot more than is necessary. And we should aim to vary our sources of protein: prioritise white meat, fish and seafood; consuming 2-3 eggs a day is ok; limit red meat and oily fish to a few occasions per week; avoid fatty cuts of meat; avoid processed meats.
The vegan’s dilemma
Protein sources that deliver all 20 amino acids needed to form human proteins are called “complete’ proteins. The problem for vegetarians and vegans is that the best sources of complete proteins are meat, fish, seafood and eggs. There are vegan sources, such as soy, quinoa and spirulina, but they tend to contain significantly lower levels of overall protein. The only real answer for vegetarians and vegans is to be incredibly conscious of protein levels in their diet, eat large amounts of the complete proteins that are available to them, and combine non-complete protein sources (e.g. nuts and beans, or soy and lentils) to avoid amino acid deficiencies.
Protein is absolutely critical to our health and wellbeing and many of us may well benefit from exceeding the official guidance of 0.75g/kg of bodyweight. But we have to be conscious of both the extra strain on our bodies of breaking down unnecessary protein and the implications of our protein sources. So it can’t be an unchecked race to the meat counter!