PART 2: To #LCHF or not to #LCHF; That’s the dietary question!

By @JohannWindt, @Liam_West & Ania Tarazi

This is part 2 of the’ To #LCHF or not to #LCHF’ Summit summary. Read part 1 HERE

In this post, we focus on the low carb high fat diet (LCHF) and performance, and finish off with the pros and cons of the #LCHF2015 summit. We hope you enjoyed BJSM Editorial team’s coverage from the summit in Cape Town! Follow the #TeamBJSM on @BJSMPlus for future SEM event coverage!


#LCHF and #EndurancePerformanceruntrackcrop

#RunOnFat – More than the name of the exclusive screening of the new documentary featuring Dr. Stephen Phinney and Prof. Tim Noakes, this describes how adaptation to a #LCHF diet may impact endurance performance. Professor Tim Noakes, Dr. James Smith, and Dr. Stephen Phinney all demonstrated that fat oxidation rates are significantly higher in athletes adapted to a #LCHF diet than any other athletes. They identify that an adaptation period is necessary for performance to return to performance levels with higher carbohydrate content. This may explain the significant portion of the research supporting high carbohydrate diets, as the athletes with lower carbohydrate content in their diets were not on the diet long enough to adapt. The increased fat oxidation level as a result of a high fat diet corresponds to slower rates of glycogen depletion, thereby offering a theoretical benefit to improved endurance performance, and less dependence on exogenous carbohydrate intake during prolonged activity. At this point, data is mixed between beneficial effects and no documented effects on endurance performance on LCHF diets. More research is necessary to determine whether athletes adapted to the diet are capable of maintaining/improving sprint performance and peak power outputs, since sprint performance appears to decrease under carbohydrate restricted conditions.

#LCHF and #Strength/Power Sports

Most of the discussion at the conference focused on #LCHF diets and endurance performance, with little addressing strength/power sporting contexts. With the exception of a study in gymnasts, showing stable performance in the presence of fat and weight loss, no literature has examined this area in depth. In addition to their potential use in helping these athletes lose fat, further research is needed as to whether this diet contributes to  significant performance benefits.

As identified by Noakes, Phinney and Volek in their recent editorial, many research questions remain in this field. Namely, the effects of #LCHF adaptation on recovery ability and total training volume, their immune function and overtraining risk, sports requiring high levels of hand-eye coordination and mental acuity (i.e. Golf & Cricket), and their efficacy in allowing for weight control. While #LCHF adaptation can significantly increase rates of fat oxidation, it remains to be seen if this translates to improved performance in endurance events.


#LCHF2015 Summit summary and final considerations 


  • The conference included a global speaker line-up and addressed #LCHF diets from a variety of perspectives, including weight, CVD risk, glycemic control, mental health, anthropology, history, psychology and more.
  • The speakers consistently voiced that low carbohydrate diets are not the only way to success/health, but that they should be considered as an effective, healthy option.
  • The conference itself ran very smoothly and was very well-organized seeing over 400+ each day register.


  • Certain portions of the conference were heavier in anecdotes/case studies than scientific data. On occasion, unsubstantiated claims without supporting data were made. During the first 3-day medical part of the conference, it is vital to remain consistently evidence-based.
  • #LCHF can cause some confusion. The demonization of “carbohydrates” can lend to the misunderstanding that all carbohydrate sources, from fruits and vegetables to refined, sugary breakfast cereals and pastries are the same. The recommendations to consume unprocessed, nutrient dense foods must be emphasized, after which point the restriction of certain carbohydrate sources may be warranted.
  • Many speakers failed to elaborate beyond the carbs à insulin à fat model, which fails to account for other factors associated with weight gain. Acknowledgement of other factors, and more thorough explanations are warranted.

Far from a simple fad, #LCHF diets have a growing body of evidence in their favour. #LCHF diets are extremely effective for weight loss, glycemic control, and improve a large number of CVD risk factors. Adaptation to this diet also significantly increases rates of fat oxidation during exercise. It is true that no long-term trials have demonstrated their efficacy beyond two years. However, the significantly positive effects from RCT evidence should validate their use, especially since the long term effects of the low-fat diet have not proven to be beneficial beyond a control diet after 8 years. To demonize them as a ‘fad diet’ fails to honestly examine the evidence, which indicates both their efficacy and safety. #LCHF diets may not the only way to eat, but they should be considered as a viable option.

With that said, many questions remain. Long-term trials are still called for to examine the effects of long-term adherence to a #LCHF dietary plan. What factors help to explain individual variability in response to #LCHF diets? What are the long-term effects of nutritional ketosis? In terms of performance, further investigation into different performance parameters, sporting contexts, recovery rates, and weight control remains necessary.

Overarching the whole #LCHF summit was an insistence on nutrient dense #RealFood, thereby #AvoidProcessedFood stripped of fiber and containing additional sugar. Thus, we conclude by insisting a focus on eating #RealFood, and if desired to try a #LCHF approach to nutrition.


Johann Windt BHK CSCS (@JohannWindt) is a graduate student at the University of British Columbia in the Department of Experimental Medicine. His research currently focuses on physical activity prescription and lifestyle counseling in family medicine settings. A certified strength and conditioning coach, Johann is passionate about improving health, body composition, and performance through evidence-based application of nutrition and physical activity. 

Dr. Liam West BSc (Hons) MBBCh PGCert SEM (@Liam_West) is a Cardiff Medical School graduate and now a junior doctor at the John Radcliffe Hospital, Oxford. He is an Associate Editor for BJSM and also coordinates the “Undergraduate Perspective on Sports & Exercise Medicine” Blog Series.

Ania Tarazi BSc (Hons)  (@AniaTarazi) coordinates the Aspetar Sports Medicine Journal in Doha, Qatar. Ania graduated from Royal Holloway University of London with an International Business degree in 2013. Her interests lie in social media engagement to promote physical activity and healthy eating in children.

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