What has become apparent to me with the discussions around the Low Carb High Fat (LCHF) diet is that there is a lot of confusion about what dietitians are actually recommending. Assumptions are being made and we know that they will ultimately get us nowhere.
Dietitians calculate individualised meal plans by working out total energy requirement and then select a macronutrient split that is appropriate for the patient. Macronutrients include carbohydrates, fats and proteins. Macronutrient splits will vary depending on nutritional status and medical conditions.
A fact sheet developed by the Nutrition Society of South Africa stated the following: “Single “best values” for population level recommendations for healthy eating are seldom appropriate. It is for this reason that recommendations across countries specify “safe ranges” for macronutrient contributions to total energy intake.
For carbohydrates the range varies between 40 to 75%, for protein between 10 to 35% and for fat between 20 to 35%. As both quantity (% contribution to total energy intake) and quality (type and nature) of macronutrients are of importance, guidance on the quality aspects of carbohydrates and fats are also included in most recommendations”.
The position paper “Dietary Fatty Acids for Healthy Adults” has been published in the January 2014 issue of the Journal of the Academy of Nutrition and Dietetics. This position paper confirms that “healthy adults should consume between 20-35 % of their calories from dietary fat”.
If the percentage of fat is above 30% total energy the diet would be considered a high fat diet. In our practice we mostly use 35-40% fat, 40-45% carbohydrates and 20% protein for weight loss. Therefore as you can clearly see, when we (dietitians) get accused of prescribing high carb, low fat diets to people it is hugely frustrating as this could not be further from the truth. As for the comments on dietitians using the food pyramid – I have personally not used the food pyramid ever as a dietitian and have been consulting for 10 years now.
We are yet to hear from Prof. Noakes what the macronutrient split of the LCHF diet is; there is no clear cut guide. It is instead based on general recommendations. At the talk we attended on Tuesday, Prof Tim Noakes stated that he recommends a diet made up of 80% fat (saturated fat) and 25g of carbohydrates. When calculated this would provide a diet that is 80% fat, 10% carbs and 10% protein.
These macronutrient ranges are extreme and are not within safe ranges mentioned above. I would like to see a referenced research article from an International peer reviewed journal that endorses this type of macronutrient split, before Prof. Tim Noakes continues to make unsubstantiated recommendations to the South African public.
- 1. Vannice, G., Calif, S. and Rasmussen, H. 2014. Position paper of the Academy of Nutrition and Dietetics: Amount and types of fat we ear affect health and risk of disease. Journal of the Academy of Nutrition and Dietetics.
- Senekal, M., Naude, C. and Wentzel-Viljoen, E. 2013. Fact sheet; Dietary recommendation for health. Nutrition Society of South Africa.