It is well established that it takes several weeks of adaptation to get the fat-burning systems functioning effectively. But there is rather more to this than simply reducing the carbohydrates and replacing them with fat. As Steve Phinney has emphasised, the mineral balance has to be considered (1). This means that if the diet is low in fruit and vegetables, steps need to be taken to ensure that adequate amounts of sodium and potassium are provided. When meat is baked, roasted or grilled, potassium will be lost unless the juice is included in the meals that are being served to the participants. Steve advocates a protein intake of about 15% Calories. If there is an inadequate supply of protein, there is likely to be a progressive loss of functional lean tissue resulting in a loss of physical performance. By contrast if there excessive consumption of protein, say about 25% Calories, there may be suppression of ketogenesis. This can manifest itself as headaches and lassitude and has been reported in those who casually undertake a “low carbohydrate, high protein”(LCHF) diet.
In an investigation in Italy the effect of adjusting to a ketogenic diet was studied in a group of highly trained gymnasts (2). At the outset, the main objective was to find out if this approach could be used to achieve weight loss without the disadvantages which are associated with the conventional methods of reducing the energy intake, dehydration and the use of saunas.
Those who agreed to take part were elite male artistic gymnasts who competed in the Italian premier league for the CorpoLibero Gymnastics Team ASD, Padova, Italy. Two of them were members of the Italian national team. They all trained for about 30 hours per week and this training regime was maintained throughout the study, during which time they were asked to exclude virtually carbohydrates from their diet. They were provided with a detailed menu containing permitted and non-permitted foods. The gymnasts were tested for performance and anthropometric measurements made at the beginning and after 30 days on the ketogenic diet. The entire process was repeated after 3 months when the gymnasts were consuming their usual diet.
The results showed that the mean body weight was reduced from 69.6kg to 68.0kg. However the body fat declined from 7.6 to 5.0%, which meant that the lean body mass increased from 92.4 to 95%. Although a comprehensive series of performance tests was conducted there was no evidence of deterioration as a result of making the adjustment to a ketogenic diet. When the procedures were repeated with the usual diet, no differences could be detected. It was concluded that the results demonstrate that the ketogenic approach can be used successfully to help athletes lose weight and is certainly preferable to the use of many of the alternatives, which may actually cause harm to the individuals. Because sufficient time was allowed for the adjustment to become fully effective, this explains why other attempts to adopt this approach have failed.
The object of this study was specifically focused on the issue of removing excess weight prior to a competition event. Nevertheless there remains the possibility the ketogenic diet could be beneficial to competitors in short events if adopted as a long term strategy. There is evidence to suggest that continual variation in body weight (weight cycling or “yo-yo dieting”) is detrimental to health. A study in the USA found that those who regularly lost weight and then re-gained it had 3 times the all-cause mortality of those who were non-obese but whose weight remained stable (3). The Italian study also noted that those who were keto-adapted had lower levels of insulin, which would mean that the scope for damage to the internal organs was reduced. In addition if the ketogenic approach was permanently applied, any concern about having to meet specific weight criteria would probably be eliminated. This could facilitate the preparation for a competition.
The Los Angeles (LA) Lakers is a top basketball team in the US. Because of concern that the poor diet of their players was having an adverse effect on the team performance. It was decided to employ Dr Cate Shanahan to review and to advise on the nutrition of the team members (4). To begin with, one of the top players, Dwight Howard was recovering from back surgery but it had not healed properly. He suffered from persistent tingling in his fingers and toes. He was in continuous pain and his performance was poor. It then emerged that he was eating the equivalent of 24 Hershey bars in sweets and soda every day. It was no surprise that tests showed that his blood sugars were at dangerous levels. Howard responded very positively to Cate’s advice and cut out all sugar, processed foods and the unhealthy fats and oils. Within weeks of starting the programme, Howard said his blood-glucose levels declined 80 percent. After increasing his consumption of healthy fats and decreasing processed carbs, all the indicators of heart health were moving in the right direction. After some initial lethargy during the detox phase, Howard said his endurance improved and his energy levels became more consistent. His body-fat percentage, which had been around 5-6% throughout his entire career, dropped to 3 percent.
Many of the other players have found that by following the dietary advice the soreness in the joints has been reduced and that muscle recovery has improved. Kobe Bryant was out of action for 8 months while he recovered suffering from Achilles’ tendon surgery and is convinced that this was helped by the change in diet. The programme is referred to as PRO Nutrition, which stands for Performance, Recovery and Orthogenesis — the latter being the theory that evolution is strongly influenced by environmental factors, such as diet. Cate Shanahan would like all the players to have at least 50% of their calories from fat, and no more than 25% each from protein and carbohydrates.
Since then Dwight Howard has moved on to Houston where these ideas are also being picked up.
Bode Miller is an American skier who has competed in 5 Winter Olympics. Prior to Sochi in 2014 he missed 2 seasons, because of a micro fracture in his knee. He decided he needed to lose weight so that he would lighten the load on his joints in order to improve his ability to manipulate himself out of precarious positions when he is about to crash. By reducing his carbohydrate intake he lost about 8kg and at the Olympics he managed a podium place with a bronze medal, which is highly commendable for a 36-year old (5).
Jonas Colting is an exceptional Swedish endurance athlete. On several occasions he has been the Triathlon Champion in Sweden as well as winning many other triathlons, long distance running and swimming events (6).
He eats lots of eggs, red meat, salmon, avocados, leafy greens, nuts and seeds. Although he is sparing with dairy he has plenty of butter and drinks full fat milk. His favourite fruits are pomegranate, blueberries, mango, citrus and bananas. He also likes potatoes, carrots, red beets and turnips. He does have some carbohydrates and enjoys the occasional bowl of pasta. He is convinced that the carbohydrate-loading that many athletes utilise is ill-advised and even if they are coping at present will ultimately cause serious health problems in the future.
There is a particularly interested case study in the Phinney/Volek book from David Dreyfuss who was trained as an engineer and scientist. He kept active throughout his life by activities such as running, including marathons, biking, hiking and swimming. Like so many others he has tried to follow the conventional dietary guidelines but despite this he gained weight and in his fifties, he reached 100kg and had hypertension, raised triglycerides and raised blood glucose. At this point he discovered “Good Calories Bad Calories”/”The Diet Delusion” by Gary Taubes (7). This led him to adopt an LCHF diet and he lost his excess weight and the other indicators reverted to “normal” although he still finds it necessary to take medication to control the hypertension. He discovered that when he ran a marathon that he no longer encountered the “wall”, which is what would be expected if the concepts of fat-burning are correct. He is absolutely categorical that after competing in an event he has much less pains and aches and that his recovery is much quicker than it ever was in the past. Despite his age, his performance is equal to or better than he was fuelled by carbohydrates.
Despite the warnings that there may be dangers associated with an LCHF diet, the fact that it is proving to be effective and usually also improves performance is pretty convincing evidence that it is perfectly safe for all. When this is combined with all the information about the benefits with respect to reducing the risks of a wide range of diseases, there can be little doubt it should be the basis for all healthy eating strategies.
- S D Phinney (2004) http://www.nutritionandmetabolism.com/content/1/1/2
- A Paoli (2012) Journal of the International Society of Sports Nutrition 9, pp34
- Vanessa A Diaz (2005) Journal of Community Health 30 (3) pp 153-165
- Gary Taubes (2007) “The Diet Delusion” Vermillion: London