Back at camp, foraging and cultivating plants and, later in our evolutionary history, grains as peasant farmers, we would have been running more on carbs, albeit low GL carbs in those days.
The Masai and Samburu tribesman, during the dry season, live almost exclusively off a diet of meat, blood and a little milk, high in protein, and forcing the bodies to burn ketones for energy. This may have given them the edge as far as hunting is concerned according to Kieran Clarke, Professor of Physiological Biochemistry at Oxford University. Having been approached by the American Defense Advanced Research Projects Agency (DARPA) she had the opportunity to test ketones as an energy source in combat situations. “They were looking for an energy source that would improve soldiers’ mental and physical performance under battlefield conditions,” says Professor Clarke. “Troops weren’t taking enough rations into action because they filled their rucksacks with extra ammunition instead. As their blood glucose dropped, they become confused, sometimes ended up shooting their own side.”
Professor Clarke had been working on ketones as a high energy source for over a decade when she approached DARPA who funded the research that allowed her to discover a way to make ketones in the lab. “No one had done it before,” she says. “We called it DeltaG which is the biochemical name for energy but also has a military ring to it - Delta Force and all.” She tried the new compound on rats a few years later and found it boosted their physical and mental performance. Those who got 30 per cent of their diet in the form of ketones ran 30 per cent further on a treadmill and were smarter at finding their way out of a maze. But that wasn’t all. The rats became much healthier. They lost body fat, actually had lower levels of triglycerides (fatty acids) in their blood and lower blood sugar levels. There were also no signs of harmful side effects. Then she tried her ketones on rowers. A group of top international rowers were given the drink shortly before they rowed on fixed machines in a lab. At the end of half an hour of hard flat out rowing those getting DeltaG had rowed on average fifty metres further in the same time than they had when they had a dummy drink. That may not sound like a lot but it can be the difference between silver and gold.
One of them beat a world record, and five beat their personal best. Muscles love ketones. “This is a very interesting new area of research,” says Dr Scott Drawer, head of research at UK Sport, who helped design the trial. “Ketones have been ignored as an energy source in sport. We need to look at them seriously now.”
Alternate Day Dieting
While running on ketones has some ‘hunting’ advantages in the short-term, in the long-term there may be disadvantages. Ketogenic diets are linked with constipation (through lack of roughage) and sometimes bad breath (the result of the way ketones happen to smell). Increased ketone levels may also lead to kidney failure, osteoporosis, cancer, and heart disease, according to NHS Direct. Also, high protein, high fat diets have been shown to have negative effects on bone mineral balance within twelve weeks. However, if you have the occasional ketogenic day, interspersed with a healthy low GL (glycemic load) diet, feeding your brain and body cells with slow-releasing sugars, that could well be the winning formula for both mental and physical energy, weight control and overall health.
In my book Burn Fat Fast (which comes out on June 6th) I advocate just this. On three days a week you eat very low GL with a maximum of 800 kcals, forcing the body more towards running on ketones. For the remaining four days you follow low GL principles, but not so strictly. You can also learn more about Burn Fat Fast here. If you don't need to lose weight as such, and are exercising extensively and want to push your performance to new heights, on the ‘fast’ days try adding a tablespoon of coconut butter to a morning smoothie of Get Up & Go, berries and chia seeds. Coconut oil, being a medium chain triglyceride (MCT), is easily converted into ketones. Alternatively, if the 800 kcals is too little if you are exercising, increase your intake of protein, ideally from fish. If you’d like to find out more read Jerome Burne’s article ‘Ketones – a good health and fat burning secret?’ in my January 100% health newsletter (issue 73). I’d love to hear how you get on if you decide to give this a go. I have a blog on ‘alternate day diets’ so you can post your comments there.