Protein has been a hot topic for some time and has always been surrounded by confusion about how much one needs and where to get it from. We all know it's one of the three macronutrients but this doesn't really tell us much at all.
Whilst we can convert most of our energy from carbs and fats, only around 8-10% of dietary protein is used for energy - the rest is used by the body to replace, regenerate and renew YOU. The body is continually undergoing restoration and repair and we need to ensure adequate protein intake to supply the raw materials for these processes. It's easy to think we are just static beings but about 330 billion of our cells are replaced every day!! That's a staggering and inconceivable number. Skin cells and cells lining the gut wall are particularly quick to be replaced, lasting on a few days.
The word protein describes amino acids, of which there are about 20 that exist singly - from these the body can combine them to make around 10,000 unique proteins. 9 of those 20 are considered 'essential', i.e. the body cannot manufacture them so they must be obtained from the diet. 3 of those 9, isoleucine, leucine and lysine, are considered the 'branch chain' amino acids required for the synthesis of muscle fibres, so especially important for strength and power.
There are very few vegetarian sources of all 9 essential amino acids (EAAs, also known as 'complete protein') that a) contain sufficient amounts and b) are easily absorbed - for example, whole grains contain protein but gluten and lectins make grains harder to digest, which is why quinoa and buckwheat are great alternatives as they do not contain gluten and are low in lectins. You may read that there are 10 or more vegetarian sources of complete protein but many of those contain negligible amounts of some of those EAAs, whilst most animal sources of protein contain EAAs in good amounts. It is, however, possible to to get adequate protein on a vegetarian diet so long as you vary your diet to obtain a good blend of different sources of protein.
More recent studies indicate around 1.6g protein per kg of body weight to prevent loss of lean muscle mass - for a 60kg individual this equates to 96g per day, or about 25-30g per meal. This becomes more important as we age, particularly for women who lose lean muscle mass more quickly than men. It is possible to overdo it - eating excessive amounts of protein can lead to weight gain since whatever the body does not need, will be converted into fat.
Tips for adding more protein to your diet:
Breakfast: eggs, pumpkin seeds, quinoa, mushrooms, peanut butter, cottage cheese and plain live yoghurt all contain high levels of EAAs.
Lunch: quinoa, lentils, peas, buckwheat, feta cheese, nuts and seeds. Combine in a salad with a nut-butter dressing.
Dinner: Tofu and tempeh are the best vegan sources of protein, containing all 9 EAAs in good amounts. Miso, lentils, peas, split peas, buckwheat and also eggs and cheese, are all good dinner-type ingredients high in protein.
Head to my recipes page for some delicious protein-rich recipes.