Protein is incredibly important. If we don’t eat enough from our diet, our health suffers. However, there’s a lot of confusion surrounding protein. How much do we need? Do requirements increase if you’re more active? Are high protein diets the way to shed the pounds? What happens if you eat too much protein? Linia Patel separates fact from fiction!
What is protein?
Proteins are the main building blocks of life and every living cell in the body uses them for both structure and function. Proteins are made from smaller molecules called amino acids which link together like Lego. Our bodies can make some of these from other amino acids but we can’t make all the ones we need and these are called ‘essential amino acids’. Essential amino acids must come from the food we eat because we can’t make them. In general, animal sources of protein tend to deliver all the amino acids we need to make new protein, but most plant proteins don’t. So, if you’re vegetarian or vegan, it’s important that your diet contains a wide variety of plant based foods.
“Older adults are less efficient in regenerating protein and so protein requirements increase with age„
Recommended protein intakes
In the UK, adults are recommended to eat 0.75 grams (g) of protein for every kilogram (kg) they weigh, every day, which is about 56g a day for men and 46g a day for women. The average protein intake is however, higher than that, with women eating 64g a day and men eating 88g a day. Although actual intakes are higher than those recommended, it’s now argued that whilst this amount prevents deficiency, it may not be enough to ensure optimal health. In reality, the “right” amount of protein for any individual depends on many factors including their age, activity level, body composition, calorie intake, current state of health and their goals.
Regular exercisers and athletes have higher protein needs than the general population for example. Extra protein helps to repair and rebuild muscle cells that are damaged during intense exercise. Strength athletes and people who do high intensity exercise have higher protein requirements (1.2-1.7g per kg body weight a day) than endurance athletes (1.2-1.4g per kg body weight a day) who have slightly higher requirements than the general population (0.75-1.0g per kg bodyweight a day). Older adults are less efficient in regenerating protein and so protein requirements increase with age. This helps prevent the reduction in muscle mass (called sarcopenia) that comes as a result of aging.
“Regular exercisers and athletes have higher protein needs than the general population„
Types of protein to consider
With protein, it’s not just about quantity – quality matters too. Some high-protein foods are healthier than others because of what comes along with the protein such as healthy fats or harmful ones, beneficial fibre or hidden salt. Good sources of protein include:
- Lean chicken, fish (oily and white) and meat
- Dried beans and lentils
- Nuts and seeds
- Low fat dairy products such as milk, yoghurt and cheese
- Soy products
Recently, the IARC (an independent body of experts tasked by the World Health Organisation) reviewed the evidence between meat and cancer risk. The panel concluded that if you ate 50g of processed meat a day (around three rashers of bacon or two big slices of ham), you have around a 17 per cent higher risk of developing bowel cancer compared to those who ate none. This might sound like a lot, but, when you put it into context of your absolute risk of developing bowel cancer, then you start seeing the risk is lowered. Your risk of developing bowel cancer is low (around 6 per cent in your lifetime) and if you eat 50g of processed red meat a day this increases your risk to 7 per cent. This is more or less the same increase in risk as being obese or not exercising. For red meat, the report showed that for every 100g serving a day of red meat, the relative risk is around the same for processed meat. The current World Health Organisation guidelines state that you can eat 750g raw or 500g cooked red meat each week.
- Processed meat refers to products that have been cured, salted, smoked, or otherwise preserved in some way and includes cold cut sandwich meats, bacon, sausages, hot dogs, ham, salami and pepperoni.
- Red meat is beef, lamb and pork.
What about protein supplements?
Supplements are not essential if you’re already getting enough protein from your food. However, if your diet is low in protein or if you’re seeking a convenient option to food after your workouts, then there may be a role for a protein supplement. Having said that, think ‘food first’ post workout – a milk drink or yoghurt would fit the bill – as it can have the same benefits.
Protein at every meal
Protein rich foods tend to make you feel fuller for longer than foods rich in carbohydrate or fat. Distributing your protein intake over the day and including a lean protein source at each meal can help you regulate your appetite and blood sugar control. The recommended minimum is 0.25g per kg body weight at each meal. The heavier you are, the more protein you’ll need at each meal.
High protein diets
Some studies have shown that high protein, low carbohydrate diets are associated with a slightly greater initial weight loss compared with low fat eating plans. However, when you look at longer duration, for example 12 months, there appears to be no difference. Long-term studies are needed to compare the effects of high protein, low carbohydrate diets on body composition and effect on disease risk.
Is too much protein a problem?
One of the biggest myths is that eating large amounts of protein equates to big biceps! Muscle is gained through a combination of resistance training and a diet that contains enough energy and carbohydrate. If you only concentrate on a high protein intake without enough carbohydrate, then the protein will be used for energy instead of being used to build muscle. Additionally, too little carbohydrate will lead to low energy levels, which will make it very difficult for you to train and perform at your best.
It’s also often argued that too much protein (particularly animal protein) is harmful to kidney function and bone health. Although protein restriction may be helpful for people with existing kidney problems, it doesn’t have any negative effects on kidney function for healthy people. For bone health, when a nutrient-dense diet is eaten – which includes a good calcium, potassium and magnesium intake – a high protein diet does not adversely affect bone health.
Take home messages
1. Keep the variety going. Choose lean protein food sources such as chicken, turkey and fish and include both white and oily fish.
2. Reduce your intake of processed meat. A ham sandwich every day is not a good idea. The occasional bacon sandwich is ok.
3. Enjoy red meat in moderation. Keep it lean.
4. Serve up some vegetarian meals. Include some meat-free meals in your menu. Plant based proteins like beans and lentils are a great addition to winter soups and stews.
References available upon request.
Linia Patel, MSc. Human Nutrition (specialising in Sport Nutrition), BSc. Med Hons. Nutrition & Dietetics and BSc. Biochemistry & Physiology, is a leading dietitian and sports nutritionist with extensive experience in a variety of settings. Her passion is to support people to become their most healthy and high performing selves!