28 May 2013
The Paleo Diet has gained an almost cult-like following since the book by Professor Loren Cordain was first published in 2002. No longer is it seen as an offshoot of ‘complementary and alternative medicine’, now many regular exercisers are jumping on the low-carb Paleo bandwagon. So, should we all be switching?
First, what’s Paleo?
The Paleo Diet is regarded as the diet that we are genetically adapted to, containing only the preagricultural food groups of meat, seafood, fruits, vegetables, and nuts. It’s based on the premise that Palaeolithic hunter-gatherers enjoyed a life free from modern diseases and that if we adopted their diet then we too could lead a longer healthier life. Proponents say that 10,000 years since Palaeolithic times is not long enough for humans to adapt to diets rich in grains & dairy. Essentially it’s a low carb, high protein/ fat diet.
What do the sceptics say?
Anthropologists say that the Paleo Diet is based on speculation – there’s little hard evidence to say exactly what hunter-gatherers ate. In any case, there was no single way of eating, as their diet varied from according to region, time period and season (1, 2, 3). Some ate grains/ legumes/ tubers (foods that are banned on the Paleo Diet!)(2, 3). They weren’t necessarily that healthy – atherosclerosis was prevalent, according to a study published in the Lancet this year (1) and most died by their 30s. According to evolutionary biologist, Marlene Zuk, evolution and adaptation can occur in 10,000 years (2) and palaeontologist Christine Warriner asserts that we are evolved to eat plants
What’s the evidence?
Very little as it turns out – there are 3 published studies that suggest the diet improves satiety, blood glucose control and heart disease risk in patients with type 2 diabetes or heart disease. But the studies were very small and aren’t necessarily applicable to everyone (4, 5, 6) On the other hand, there’s no shortage of anecdotal evidence to say that it produces weight loss, and has favourable effects on major risk factors.
Is it suitable for athletes?
Many exercisers extol its benefits: weight loss, plenty of energy, etc. The main problem for serious athletes is the low carb content. This means training/ competing with low glycogen, which years of research tell us reduces stamina, performance in competition and, in the long-term, can result in the over-training syndrome. Even Loren Cordain concedes this basic point. In his sequel, The Paleo Diet for Athletes (7), he tells athletes to bend the rules (!) and eat carbs 2 hours before exercising, during and after. Hmmm… so we do need carbs then. Also – and this is what puzzles me most – he advocates sugars, sports drinks, gels, and white bread – the complete antithesis of Paleo living!
It won’t do any harm if you’re exercising at low or moderate levels to lose weight or improve health, or do intermittent exercise (e.g. weights). But for elite athletes and those who train at high intensities longer than 90 minutes interested in maximising performance, then you’ll need more carbs! I would also advise including dairy products or whey protein (milk proteins stimulate recovery and muscle synthesis).
Recent studies suggest you can ‘train low compete high’ i.e. ‘force’ the muscles to use fat for fuel when you eat a low carb diet but – and there’s a big but – there is no evidence that fat-adapted athletes produce a better performance (8, 9, 10)
There are some good points about the Paleo Diet: its emphasis on unprocessed, ‘whole’ and fresh foods, the avoidance of unnecessary sugar, and the inclusion of fats and protein.
Does it help athletic performance? Paleo may get you through your day to day training OK but there’s no evidence from studies yet that this results in better performance during competition. At the end of the day, carb intake is very individual – if a lower carb diet works for you and you’re feeling full of energy then carry on. If you’re getting great results on a high carb diet and you are not overweight then carry on. It’s not possible to use a one size fits all approach when it comes to nutrition for sport.
- Thomson RC et al (2013) Lancet Mar 11.
- Zuk, M (2013) Paleofantasy: What evolution really tells us about sex, diet and how we live
- Warinner, C. (2013) http://tedxtalks.ted.com/video/Debunking-the-Paleo-Diet-Christ
- Jönsson T, et al. Beneficial effects of a Palaeolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study. Cardiovascular Diabetology 2009, 8:35.
- Lindeberg S, et al. A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia. 2007 Sep;50(9):1795-807.
- Jönsson T, et al (2010) ‘ A Palaeolithic diet is more satiating per calorie than a Mediterranean-like diet in individuals with ischemic heart disease. Nutr Metab. Nov 30;7:85. doi: 10.1186/1743-7075-7-85.
- Cordain L & Friel J (2012) The Paleo Diet. Rodale
- Hawley et al. (2011) Nutritional modulation of training-induced skeletal muscle adaptations. J Appl Physiol, 100 pp. 834–45.
- Hawley, J. A. & Burke, L. M. (2010) Carbohydrate availability and training adaptation: effects on cell metabolism. Exerc Sports Sci Rev, 38 pp. 152–160.
- Maughan, R. J. and Shireffs, S. M. (2012) ‘Nutrition for sports performance: issues and opportunities’. Proc Nutr Soc; 71 (1), pp. 112–9.