Protein is a vital aspect of our diet and a crucial component of every cell. It is often referred to as the ‘building blocks of life’. Our digestive system breaks down protein to single bricks called ‘amino acids’ which our body absorbs and assimilates not only into muscles but also bones, collagen structures, neurotransmitters, hormones, immunoglobulins, transport proteins and other.
It also helps to keep blood glucose stable, keeps us fuller for longer, prevents cravings, snacking, sudden energy dips, ‘hanger’ and bouts of anxiety.
Increased protein intake is key on a weight loss journey - for body recomposition goals including muscle growth and the reduction of fat tissue. Increased protein intake prevents muscle loss which is a common issue these days due to chronic stress and a hectic lifestyle (during stress, muscle is used to create glucose to fuel up the constant fight-or-flight). I think that this is the main reason why we need a lot more protein these days. Those who retired, lead a more relaxed lifestyle and those who have no children generally do ok with smaller amounts.
More protein is indispensible in mood disorders, poor immunity and all autoimmune conditions. It is an unquestionable must for babies, children, pregnant and perimenopausal women, those who are stressed and on the go a lot.
Anyone who wants to heal should look into more protein.
The two main drivers of insufficient protein are:
• inadequate consumption of quality protein throughout the day
• impaired protein digestion and assimilation, regardless of adequate intake
What is quality protein?
There are two main factors which determine protein quality:
How digestible it is for humans (this determines how usable a protein is)
How many essential amino acids it contains (‘essential’ means that the body cannot make these and they have to come from food)
The DIAAS score is the latest measure of such protein quality. It evaluates which consumed amino acids are absorbed and utilised by the body.
a score of 100 or more: high quality protein
a score of 75-99: good quality protein
a score <75: low quality protein / no protein claim can be made
In other words, it’s not the question of how much total protein there is in a food but rather if it’s of any use.
For example, peanut butter may have a decent amount of protein but it is lacking certain essential amino acids. Peanut butter scores only 46 which doesn’t qualify it as a protein. This does not mean one should not eat peanut butter! It provides plenty of nutritional value in the form of fibre, phytoestrogens and fats. It just isn’t a strong candidate for usable protein.
Protein requirements and serving sizes
In order to prevent malnutrition, the WHO recommends approximately 0.8 gram of protein per 1 kilogram of lean body mass. However, optimal intake goes beyond just bare survival and warrants that ALL bodily functions that depend on protein incuding mood, immunity and hormones, work well.
Functional optimum for protein intake ranges between 1.2 - 1.6 grams per 1 kg of lean body mass, which depends on one’s goals, fitness level and health status. Most of my clients don’t meet adequate protein requirements when we first meet.
I usually recommend 90-120g of protein for women and 100-150g for men per day. It can be divided into 25-35g of protein, split between 3-4 meals and snacks if needed. 30g per each main meal is a good place to start.
Again, this depends on individual factors. Protein has a limited absorption rate, meaning that if a lot is eaten in one sitting, some of it will remain undigested and reach the colon where it will undergo putrefaction under the influence of gut microbes. It is the undigested and putrefied protein that is associated with adverse health effects, including colon cancer. If your protein demands are bigger, then it is better to add an extra meal or snack rather than having a very large serving in one go.
Last but not least, addressing the gut and improving digestion by stomach acid, brush border enzymes and pancreatic enzymes is key to benefit from an increased protein intake while keeping health risks at bay.
Best sources of protein
I compiled a list of the best protein sources according to the highest DIAAS scores, 75 and up. The amount of protein in the amounts below is approximate.
Meat:
Chicken breast (100g): 28g
Lean pork cuts like tenderloin and ham (100g): 26g
Fattier cuts of pork like ribs and shoulder (100g): 18-20g
Lean steak like sirloin (100g): 26g
Fattier steak like ribeye (100g): 20-22g
Beef burger (100g): 20g
Organ meats (100g): 22-25g
Chicken thigh: 22g
Sausages without fillers (100g): 16-20g
Lamb chops, 3: 22g
Traditionally cured meats like Iberico, Serrano, Parma ham (100g): 25g
Seafood:
Oily fish like sardines, mackerel, anchovies, salmon, herring (100g): 20-25g
Non-oily fish like tuna, hake, sea bass (100g): 22-26g
Prawns 10-15 large: 24-26g
Crab, 1 leg: 24-26g
Clams, 10: 25g
Mussels, 20-25: 22-24g
Scallops, 6 large: 20-22g
Tinned fish in brine or olive oil (50-60g of net weight): 12-15g
Vegetarian:
I don’t recommend exceeding the amounts of dairy below in order to get more protein. Dairy is generally inflammatory and insulinogenic. It is better to combine protein sources to reach your goal, e.g. eggs and cheese.
Cottage cheese (200g): 24g
Egg, 6g
Feta (50g): 7g
Greek yoghurt, fat free or low fat (full fat is predominantly a source of fat) (150g): 15g
Halloumi (100g): 22g
Kefir (250ml): 8g
Paneer (100g): 18-20g
Skyr (150g): 15g
Whey protein isolate, 20-25g per serving, depending on the brand
Vegan:
As above, exceeding the numbers below in order to maximise protein intake may cause adverse reactions, especially digestive, inflmmatory and hormonal when eaten in larger amounts and on a regular basis. It is best to stick to the maximum recommended serving sizes. Legumes and quinoa are considered high protein vegan foods but they are mainly a starchy carbohydrate. Quinoa does not even make it to the list. By increasing the amounts to rich a protein goal, one will also significantly increase starch.
Seitan also scores high but because it is pure gluten, I will not recommend it to any of my clients.
Chickpeas (75g cooked): 7g
Edemame (75g cooked pods): 8g
Natto (100g): 18g
Pea protein powder: 15-20g per serving, depending on the brand
Tempeh (100g): 18g
Tofu (100g): 8g
Yellow split peas (100g of cooked): 8g - borderline as yellow split peas scores 73