According to the National Diet and Nutrition survey, our intake of protein is well above the recommended intake in all age groups, with many of us consuming 45-55% more protein.
With the huge boom in sales of protein powders, shakes and bars over the last few years, do we really need to be supplementing our diets or can we reach our protein intake from consuming a balanced diet alone?
Let's start off by taking a look at what protein is and why we need it in our diet.
What is protein?
The word “protein” comes from the Greek meaning “of first importance”.
Protein, carbohydrates and fats are all macronutrients. The body requires these nutrients in relatively large amounts to grow, develop and thrive.
Proteins are made up of chains of amino acids. There are around 500 amino acids known to man but only 20 appear in our genetic code. Of these 20, 9 are considered “essential” in our diets because our bodies cannot produce them from other compounds and they therefore must be taken in as food.
Why do we need protein in our diets?
Protein is the main structural component of all cells in the body. It provides the essential building blocks to grow and maintain muscle, as well as bones, skin, hair, nails, arteries, veins, enzymes and hormones.
It has been shown to increase feelings of fullness to a greater extent than carbohydrate or fat, which will help you reduce your overall energy intake and manage your weight.*
Where does protein come from?
Protein is found in both animal derived products such as meat, poultry, fish, dairy and eggs, and plant foods including grains, legumes and nuts.
In the UK we are recommended to consume 0.75g of protein per kg of bodyweight. So if you weigh 70kg, then you are recommended to consume around 52.5g of protein per day. Athletes, particularly elite athletes, are recommended to increase their protein intake to around 1.2-1.7g per kg of bodyweight, to help build and repair muscles. Requirements for protein may also vary depending on individual factors, such as stage in life, illness and injury.
Below I have included a rough estimate of the amount of protein in a normal portion of these foods:
• Size of your palm/70-100g cooked meat, poultry or fish = 20-30g
• Two eggs = 14g
• 30g cheese = 7g
• 100g natural yogurt = 5g / Greek yogurt = 10g
• 80g beans such as kidney beans = 6g
• 25g nuts such as almonds = 5g
• 180g (cooked) brown rice = 6.5g, quinoa = 9g, brown pasta = 7.2g
• 2 slices wholemeal bread = 9g
• 80g tofu = 8g
• 80g peas = 4g, broccoli = 3.5g, kale= 3g and spinach = 2g.
Protein-rich foods are often rated in terms of how “complete” their amino acid profile is. A “complete” protein will contain an adequate proportion of all the 9 essential amino acids necessary for the human body. As we are biologically much closer to a cow than a carrot, the protein content of animal derived products are generally much more similar to our own. “Complete” proteins are therefore mostly animal products including meat, poultry, fish, eggs, milk, cheese and yogurt, but also include a few plant foods such as quinoa, soya beans and buckwheat.
The amino acid profile of many plant foods is often deficient in one or more amino acids, making it “incomplete”. Vegetarians and especially vegans are therefore recommended to combine proteins to raise their amino acid profile. Vegetarians who eat plenty of dairy and eggs should be getting enough protein in their diet, but vegans who do not consume any animal protein need to make sure they are getting enough protein by eating lots of grains, legumes and nuts. There are a few traditional dishes that already combine legumes with grains to create a dish that is high in all essential amino acids. Examples include rice and beans, pitta and houmous, and a peanut butter sandwich!
It's important to remember that not all sources of protein are equally as good for you. Animal derived protein, such as red meat, contain more saturated fat than plant foods and have been shown to raise blood cholesterol levels and increase the risk of heart disease. I would recommend limiting your intake of red meat to once or twice a week, eating oily fish at least twice a week, eating a moderate amount of dairy and filling your plate with lots of fresh fruit and veg, legumes and grains.
What happens if we eat too much protein?
Our bodies are capable of absorbing a large amount of protein but our muscles can only utilise around 20g of protein at one time. Someone consuming a very high protein diet may therefore not necessarily be building more muscle mass than someone consuming less than them.
If we consume too much protein, it is broken down by the liver and removed from the body via the kidneys or used as energy. In healthy people a high intake of protein may not necessarily pose a problem to the kidneys or liver, particularly over a short period of time. However, the impact of a high protein diet over a long period of time needs further investigation. In those who already suffer from kidney or liver disease, or are at high risk, a high intake of protein may put unnecessary strain on these organs, as the body may have trouble eliminating the waste products of protein metabolism.
Do we need protein supplements?
Protein supplements, such as powders, shakes and bars, have been used by elite athletes and body builders for a number of years. However, over the last year or so, you may have noticed the increase in protein products in the supermarkets. We've been fascinated by the use of protein to build muscle, to help sustain hunger and for weight loss.
As we are recommended to consume protein within an hour post-exercise for maximum protein synthesis, protein supplements are often seen as more efficient and convenient than eating a protein-rich meal. This may be the case for elite, strength or endurance athletes, but for those of us who do light or moderate exercise 3-5 times a week, a balanced diet will provide you with all the protein you need. The key is to be prepared, if your away from home and you know it’s going to be a few hours after your workout until you eat a balanced meal, then take some snacks with you. For example, some slices of chicken, hard boiled eggs, a yogurt, pitta bread and houmous or a packed of our Full of Beans Protein Mix.
The ideal way to nourish your body is to balance protein with other macronutrients (carbohydrates and fats) throughout the day. Make sure you are consuming a variety of protein foods as part of a well-balanced diet.
Take home message
Protein is a very important nutrient in our diet, essential for a number of bodily processes, to grow and repair muscles and for keeping us full. By consuming a well-balanced diet, you should be able to meet your recommended intake of protein. Find out what works best for you and adapt it to your lifestyle.
Speak again soon
Gemma, The Food Doctor nutritionist
- Paddon-Jones D, Westman E, Mattes D R, Wolfe R R, Astrup A, Westerterp-Plantenga M. Protein, weight management, and satiety. Am J Clin Nutr 2008; 87: 15585-15615.