There are more sources of energy than carbohydrates, one doctor says.
Recently I came across the article of Dr Eades: Nutritional ignorance abounds. It is one of many articles on his blog and I have noticed that he has the same mission as I have: to critically comment or debunk the nutritional nonsense out there. This article reminded me my numerous amazements when reading flawed articles in media and how I wanted to shout out: ‘This is nonsense! Have they lost their mind?’
I know exactly how Dr Eades felt in 2010 when he was writing his article. HOWEVER, this doctor is promoting a low-carb approach, hence the website: proteinpower. I think this has hugely biased his views. In addition, I guess Dr Eades either knew little about sports nutrition or, if he knew a lot, he ignored it, otherwise he would probably have avoided writing his article completely. He criticized a short magazine article aimed at golf players with arguments applicable onto average population with low levels of physical activity. I am very grateful that the nutrition students at LondonMet have a Sports Nutrition module included in their curriculum. This opened my eyes to see such claims in media from another perspective so that I can understand why the registered dietitian might have recommended the carbohydrates to sportsmen. By the way, the LondonMet dietetics students shared this module with the nutrition students. I don`t know how it is in the U.S. though.
I agree with Dr Eades that our body uses various sources of fuel in addition to carbohydrates: the fats and proteins. Our bodies metabolize all three substrates at any moment during the day, only their ratio changes depending on the actual needs and their availability. But why he did not check his view with a sports nutritionist? As I am not too familiar with the dietary requirements of golf players, I just typed “golf energy requirements” key words into the search engine and pressed enter. A quick look through the results and exclusion of drink industry articles forwarded me to this great article written by a certified sports nutritionist Dr Ralph Jäger: Golf performance nutrition. This article was also written by a doctor specializing in sports nutrition, unlike Dr Eades. Yes, they promote their own brand of supplements, but the article contains some valuable evidence about the energy requirements of golf players and several tips about how to balance their diet with proper food, too. Their customers do not have to rely on expensive snack products. All references listed below the article are older than the article of Dr. Eades, which means that if he had put an effort and researched the subject, he would have written a different article or didnot write it at all. Even the general and currently accepted sports nutrition principles are older than 2010.
Dr Eades refused the exclusive carbohydrate approach and promotes high-fat and low-carbohydrate snacks for golf players, literally going from one extreme to another. The certified sports nutritionists Dr Ralf Jäger recommends the middle approach:
“A round of golf is considered to be a moderate-intensity endurance exercise. Golfers use equal amounts of fats and carbohydrates as sources of energy during a round of golf. In other words, regardless of how you play the course, the fuel your body burns, whether carbohydrates or fats, is almost identical“.
This looks more appropriate to me as well. If the golfer wanted to lose weight, then fine. Low excursions of insulin after a low-carbohydrate food would encourage fat cells to release fatty acids for metabolism. I would agree in that with Dr Eades. But this might not be the case of slim and fit golf players pictured in the article he criticized and there was nothing mentioned about their adiposity issues as well. Moreover, I have noticed nothing such as exclusive carbohydrate promotion by the registered dietitian. She actually recommended the same thing as any sports nutritionist would. I would even not pick on the white bread and some sugar when these are supplied with proteins or little fats, since the latter two substrates would slow down the digestion and absorption of the former one, allowing for a slow and gradual release of energy. Moreover, the physical activity would not let the energy molecules circulate through the veins without the use and to be saved in the adipose tissue. They would probably be used as a fuel throughout the continuous activity, posing no risk to the body mass of the players. Indeed, the dietitian positively evaluated the content of proteins and healthy fat in the snacks discussed there. Even the emphasis on the carbohydrates can be understood since the original article was related to sport. Carbohydrates play a crucial role in most sports and Dr Eades has missed this point. What I can see is that Dr Eades distorted the dietitian’s recommendations towards his enemy zone, so that he could contradict this distorted image and write a lengthy article about it, promoting his low-carb approach instead.
Then came the agave nectar, rich in fructose, which was criticized by the doctor as dangerous. I can see that he had also bought the hysteria about the dangers of fructose. One fact is that its consumption is not causing spikes in glucose levels followed by spikes of insulin, which is exactly what he tries to achieve with advocating high fat snack. In addition, this low-insulin release property of fructose is welcomed by some people experiencing a so-called reactive hypoglycaemia. This happens when they supply their system with a lot of glucose based fast carbohydrates (sugar, white bread) at once and then the insulin rapidly lowers their blood glucose, so they suddenly feel tired, dizzy or nearly fainting. Another fact is, and this is rarely admitted by the scientists, that in humans large portion of ingested fructose is converted to glucose and lactate, more precisely 41% and about 25%, according to Sun and Empie (2012). This process takes time and it does not require immediate response of insulin in concentrations typical for the comparable amounts of glucose intake. Moreover, physically active people are less likely to experience adverse effects of some extra fructose (how much could be provided in agave nectar sweetened muesli bar?). These adverse effects were achieved by studies designed to challenge the metabolism of the participants. The examined subjects were followed under reduced physical activity regime (up to 3 hours of exercise per week, usually less) and they were fed with amounts of fructose beyond the normal human consumption. I will discuss this in one of my articles of the Fructose and metabolic syndrome series.
I would like to say one more thing before the potential critics pull the trigger. I know, that the review of Sun and Empie (2012) have declared a conflict of interests. However, the studies they included contain a relevant evidence about fructose metabolism in humans and despite a likely reporting bias by the Sun and Empie, these bits of evidence cannot be ignored. The study of Chong et al. (2007) contains high quality data about the metabolic fate of isotopically labelled substrates which were better controlled than in most of other studies. The team examined not only the isotopically labelled fatty acid palmitate, from which other scientists readily concluded their results about the fructose induced de-novo lipogenesis, but the team also studied labelled fructose and glucose. I consider this method as superior to the other simplistic methods. If you have better data or more in depth explanation of the mechanisms of fructose metabolism in humans, please share them with us. Thank you.
Chong, M.F., Fielding, B.A., Frayn, K.N. (2007) Mechanisms for the acute effect of fructose on postprandial lipemia. American Journal of Clinical Nutrition 85, pp: 1511-1520
Eades (2010) Nutrition ignorance abounds [Online]. Available at: http://www.proteinpower.com/drmike/fast-food/nutritional-ignorance-abounds/ (Accessed: 10.4.2014)
Jäger, R. (2011) Golf performance nutrition [Online]. Available at: http://iqplusfoods.com/golf-performance-nutrition (Accessed: 12.4.2014)
Sun, S.Z., Empie, M.W. (2012) Fructose metabolism in humans – what the isotopic tracer studies tell us. Nutrition and metabolism 9:89