Like many who've spent the best part of 5 years at medical school I seem to know very little about nutrition. Sure, as someone who works in critical care I can help treat nutritional emergencies, but the day-to-day knowledge of what I should and shouldn't be eating is sadly lacking. As I've got older I've tried to work it out. This is simply because I want to keep doing what I'm doing and I've a feeling that the right combination of protein, carbohydrates and fats might just help! But that's it, it's nothing more than a feeling. I was therefore very interested to read the dietitian Rebecca Dent's Nutrition For The Ageing Athlete that recently appeared on the excellent Uphill Athlete website. I recently got in touch with Rebecca to ask her more about the role protein plays in those planning to remain active well into their dotage.
Rebecca is based in Chamonix where she runs her own business specialising in providing a nutrition service to endurance and adventure sports; including mountaineers, alpinists, mountain guides, ultra runners, ironman triathletes, climbers, ski tourers and expedition members. Rebecca’s career spans over 15 years in health and sport. Her journey started in the NHS where she specialised in weight management and working in the area of bariatric surgery. Following completion of her MSc in sports nutrition in 2006, Rebecca headed into the mountains of Chamonix to work with enthusiastic young ski racers at the British Ski Academy. This led her to becoming a performance nutritionist at the high performance epicentre, Sport Scotland Institute of Sport (SIS), working with national and Olympic athletes. In 2010 Rebecca fulfilled a career ambition by supporting athletes towards the Vancouver Winter Olympics. During her time at the SIS Rebecca gained a sports nutrition diploma with the International Olympic Committee. Recognising the deficiency of sound science based nutrition practices in outdoor and adventure sports, in 2011 Rebecca set up her own business in this field.
Thanks Rebecca for helping to shed some light on this fascinating field. Many of those reading this post will know the basics - that proteins are chains of amino acids that are essential for cells to function normally and from an athlete's perspective, adequate protein is essential to build muscle, maintain strength and ensure recovery. To meet these needs you ask your clients to consume between 1.4 and 1.6 g/kg of protein per day. However, in the UK the Reference Nutrient Intake (RNI) is much lower at just 0.8 g/kg.
Can you explain the difference?
This minimum RNI is set to meet the daily recommended intakes for health. When training and exercising on a regular basis your body requires an increase in protein to support recovery and training adaptations such as an increase in musculature and other metabolic processes that all require additional protein from the diet. Recovery from exercise is a 24hr process with an ongoing process of muscle make up and breakdown, the aim of an increased protein intake is to primarily support muscle recovery. With age, the RDA has in fact changed recently and been increased to 1.2g/day to account for age related muscle mass loss and research has shown this increase in protein intakes with age (>65yrs of age) can help support muscle mass loss that occurs with ageing. Research has shown we can still gain muscle mass into our 80’s but a stimulus is still required (i.e. exercise and protein intake). This increase in older age takes into account the associated age related degeneration of physiological processes such as digestion, increase inflammation, insulin resistance and anabolic resistance. If that person who is older than 65 still exercises on a regular basis and is not sedentary I would still consider advising 1.4-1.6g/kg/day.
Time to put my breakfast under scrutiny - muesli, nuts, yoghurt and fruit. Here's Rebecca's thoughts, "This is a great go to breakfast, I would suggest choosing a good quality muesli without any added sugar, including healthful fats is important in each meal so a handful of nuts are nutritious and also contribute a small amount of protein. I would suggest swapping the natural low fat yoghurt to a good quality Greek yoghurt, such as Fage Total Greek yoghurt, Skyr type yoghurt. These are higher in protein at approx. 9/10g per 100g. I would recommend adding 200g of this higher protein yoghurt to achieve the recommended 20g of protein per meal. I would also suggest a handful of berries on top of your muesli would add to one of your 5 portions of fruit and vegetables a day."
Let's put the numbers now into "real life". I'm 80kgs. So 120g of protein seems like a reasonable target to aim for. What's the best way for me to get what I need?
The best way to consume this amount is to spread this throughout the day at 4 hourly intervals e.g. breakfast, lunch, evening meal, post exercise and/or pre bed. Aiming for a minimum of 20g per meal (or approx. 0.4g protein per kilogram body weight per meal). As mentioned recovery is a 24hr process and timing of protein rich meals spread through out the day can support adaptations and recovery to exercise. What is important to note is that these guidelines are provided in relation to physical exercise (resistance, endurance, high intensity). Other research has shown that increasing protein intakes can also support weight loss goals (protein promotes satiety, leaving you feeling fuller for longer) and has also been shown to help manage energy levels throughout the day.
You mention the need for "high quality protein food sources" in your postings. What does this mean?
This means protein rich foods that contain sufficient and the right type of amino acids (essential amino acids) to aid adaptations and recovery from exercise, protein rich food source examples include; dairy (milk, cottage cheese, greek yoghurt), eggs, lean meats, fish and good quality protein rich vegetarian / vegan sources including tofu, quorn, quinoa, hemp seeds. These protein rich food sources are easier to digest and have a greater bio availability. In the main as long as you are consuming enough protein throughout the day it will not matter if you consume these proteins with a source of carbohydrate/fat. The guidelines are inclusive of meals (that contain fat and carbohydrate), after all we eat foods, not macronutrients!
Now for lunch - Beans on Toast - Here's Rebecca again, "Simply add an egg or two to the top of the beans (a half tin (200g) of baked beans is 12g of protein) so I would recommend 200g of baked beans onto your toast topped with one egg (~7g protein per egg). If you avoid eggs then perhaps you can make some scrambled tofu to go on top of your toast".
Can vegetarians and vegans access sufficient "high quality protein food sources”?
Yes but you have to be a bit smarter and plan your protein intake better. Most plant proteins do not provide all of the essential amino acids required for health and exercise from one food type. Therefore plant proteins are deemed as incomplete proteins. Proteins from animal sources are deemed as complete proteins, as each of these protein food types contain all of the essential amino acids required for health and exercise. Therefore it is recommended as a vegetarian/vegan to combine different types of plant proteins in one meal to achieve a balance of all of the required essential amino acids.
Suitable foods include; soy (tempeh, edamame, tofu) quinoa, hemp seed, chia, Quorn (complete proteins) and a mix other plant based sources such as beans and lentils, rice and peas (in order to obtain a complete balance of proteins).
What sort of feedback do you get from those trying to consume this amount of protein. What obstacles do they encounter? How do they get over them?
I would say the majority report a positive response, that they fill fuller, better energy levels through out the day, they report feeling leaner and noticing an improvement in recovery. I am not sure I have had any clients who struggle to eat this amount or have any barriers to implementing these quantities. It is my role as a sports dietitian to help provide practical guidance on how to easily implement this amount of protein from a food first approach and then add in protein supplement sources as required. Usually it is about adding more protein food sources on top of pre-existing food intake, not completely over hauling someone's dietary intake. Most already consume sufficient at main meals but it is usually breakfast where people fall short and potentially a pre-bed protein and post exercise recovery intake may also be beneficial for some depending on activity levels and training goals.
Thanks Rebecca for helping shed some light on this fascinating field!
For further information about the role of protein in the diet Rebecca recommends this review.
Rebecca can be contacted through her website.