I must quantify this article by stating that I am not a qualified Nutritionist or Dietitian, so this article is only for informational purposes. It was sparked by my current study of Nutrition – I am currently undertaking 2 courses in Nutrition among other things – and my great interest in the never ending debate about the role of carbohydrates in the weight loss matrix. If you would like some advice on the courses that I am doing please feel free to e-mail me and I will happily share my experiences.
You might have heard of the expression that ‘fat burns in a carbohydrate flame’. This is taken the mean that humans need carbohydrates to utilise stored fat. This is at least partially true.
The Krebs Cycle is a ubiquitous cellular system of enzymes that allows our cells to generate energy. Without it cellular respiration would cease. For this cycle to function most efficiently a compound called oxaloacetate must be present in reasonable amounts. With enough oxaloacetate in our cells the Krebs Cycle doesn’t run very smoothly. When we consume carbohydrates they are eventually broken down to a molecule called pyruvate, which can then be converted into oxaloacetate. Are you with me?
So without adequate carbohydrate metabolism the concentration of oxaloacetate will drop and the Krebs Cycle will not function very efficiently. This helps to explain why people will often feel very sluggish when they begin a carbohydrate controlled diet – they are not producing enough energy at a cellular level to meet their energy demands. Everything from brain function to physical capacity begins to slow down to match the reduced Krebs Cycle activity.
Does this mean that low carbohydrate diets are nonsense? Not really.
If people have enough body fat and are consuming enough dietary fat their body will compensate – after 7-14 days – to this reduced oxaloacetate volume and start producing more Ketone Bodies. Ketone Bodies are produced by the liver from fatty acid molecules at times of caloric or carbohydrate restriction and are readily transported around the body to all cells where they can help to keep the Krebs Cycle ticking along. By this stage the cells have increased the volume of enzymes functioning within the Krebs Cycle to help to compensate for the lack of oxaloacetate, which is usually needed to start the cycle. Clever, right?
This is what is called ‘fat adaptation’ and by this stage people often subjectively report feeling better than they did even when consuming carbohydrates. Some people, however, never make this adaptation and for them they never feel better. This can be for a number of reasons, and without knowing the precise number and volume of metabolic enzymes within our client’s cells, as coaches and trainers we can never be sure who will respond best to which type of diet.
Coming full circle, this is why even though fat does burn in a carbohydrate flame, some of our clients will function very well on low carbohydrate diets. A skilled coach will be able to help their clients identify this and adjust their eating plan accordingly.
Yours in health!
