Protein – we hear about it all of the time, products in the supermarkets are emblazoned with the word and it generally gets a good press compared with fats and carbohydrates.
This blog aims to give you a few go-to bits of information about what it is, why our bodies need it, how to know whether you’re getting enough from the right sources and whether too much of a good thing is a bad thing.
Protein is one of 3 macro nutrients – nutrients that our bodies need in larger quantities in order for our bodies to work effectively. Our bodies break down (metabolise) protein from the foods we eat into amino acids which are the individual molecules or building blocks proteins are made from. There are 20 in total; 9 essential and 11 non-essential. These amino acids are absorbed by the bloodstream and transported to our cells to be synthesised back into proteins for repair and growth of the body’s tissues. There are different types of proteins: dietary, structural, homeostatic and fuel which are used for specific jobs such as:
- maintaining a healthy Ph balance within our blood and other body fluids;
- boosting our immune system by helping to form antibodies which help us fight infection;
- synthesising hormones and enzymes;
- repairing and building muscle tissue, tendons, ligaments, skin, hair and nails;
- facilitating muscles to contract and relax.
Our bodies are made up of thousands of proteins (scientists reckon somewhere around 20,000 different ones!) which make up the structural components of our cells and tissues; as our food is where our protein comes from, dietary protein is very valuable to our bodies. It weighs in at 4 calories/gram, the same as carbohydrates in fact, however due to it’s valuable properties, it is not the body’s preferred source of fuel for energy in normal circumstances. It is harder to metabolise and therefore expends more calories to digest compared to carbohydrates and fat. Excess protein cannot be stored, so leftovers, once growth and repair needs have been fulfilled, will be stored as fat or expelled from the body as urine. Excessive amounts of protein in our diet can mean that the concentration of urea and therefore nitrogen in the urine is too high which can lead to problems with our kidneys and liver.
So where does protein come from?
In order for the biological processes such as breathing, sleeping and all other chemical reactions keeping us alive and well that occur within our bodies, we should consume a healthy diet which consists of a balance of macro nutrients (carbs, proteins and fats) and micro nutrients (vitamins and minerals.) In addition, we need to consider how to fuel our daily movement, physical activity and recovery from this.
The million dollar question then – how much should I eat and where in my diet will it come from? The British Nutrition Foundation (https://www.nutrition.org.uk/healthy-sustainable-diets/protein/) state that an average person in the UK is consuming above the recommended daily amount – this includes people who prefer a vegetarian or vegan diet. Daily protein amounts are calculated at 0.75g per kg of bodyweight, so for example, a person who weighs 60kg (9 stone, 6lbs) and takes part in some physical activity such as going for a run or doing an exercise class for example, 45g of protein per day is recommended. For someone who weighs 42kg (11 stone, 10lbs), 56g of protein per day is recommended. Protein needs vary throughout our lifetime and at certain times such as if we are trying to build muscle, lose weight or recover from illness for example. For people training at a higher level – e.g. regular strength training rather than just the occasional run or exercise class – considering timing of eating protein e.g. after an intense resistance workout can support efficient muscle repair and growth.
What do these quantities of protein look like in the food I eat and are all sources equal?
These recommended daily intakes can be satisfied by eating 2 portions of lean meat, fish, nuts or tofu per day – a portion of protein should roughly fit into the palm of your hand. The satiety value of protein is high, therefore it can help with weight loss as it takes your body longer to break down, keeps you fuller for longer and your body expends more calories to digest it compared to fats or carbs – this is known as the thermal effect of food.
Choosing a wide variety of low-fat, protein sources is the best option. Go for foods which are minimally processed as often as you can to avoid eating extra calories in added or naturally occurring fats and sugars; this means foods which are closest to their natural state as possible; think: field, tree, ground and sea!
Here is a short list of commonly eaten foods and their approximate protein content (which can vary between brands and sources):
| Portion size | Food type | Approx grams of protein per portion |
| Animal sources: | ||
| 2 medium | egg | 12g |
| 1 hand-sized | chicken breast | 60g |
| 1 hand-sized | haddock fillet | 22.6g |
| 125g | natural full-fat yoghurt | 5.75g |
| Plant sources: | ||
| 125g | tofu | 21.8g |
| 33g | unroasted, unsalted peanuts | 7.7g |
| 33g | unroasted, unsalted almonds | 6.3g |
| 50g cooked | quinoa | 2.0g |
Animal proteins are complete proteins and are the best choice in terms of gaining all 9 essential amino acids which are required, but cannot be made, by our bodies. If however you have allergies, intolerances or follow a plant-based diet which means animal sources are not an option, there are a small selection of plant food sources which also provide all 9 essential amino acids; quinoa and tofu being 2 examples. So, at first glance, quinoa seems an inferior plant-based option however in terms of value of the amino acids available from it, they are superior to those found in peanuts.
In terms of deciding which food sources to choose then, it is clear that not all sources are equal. In addition to the surface value of protein content as above, it is important to consider how useful that protein is to our body.
If you have found this useful but would like more information about how this applies to you individually, book in with one of the team for a chat about how your food choices can help support you in achieving your health and wellness goals.