The keto-adapting eating styles abound – Paleo (Cordain), Primal (Sisson), Pegan (Hyman), Wheat Belly (Davis), Atkins (Induction Phase), Virgin and I am sure I missed a few of them. At the end of the day – what do these plans all represent? The ability to utilize your body fat for energy.
I am a biochemist and I devour this information – so, it is a little more difficult to tone down the ‘wonkiness’ of this blog topic. So, I hope I give you enough information so that you want to learn more.
First off, why do you want to be keto-adapted? When you are keto-adapted, the body doesn’t have sufficient glucose (glycogen) to use as energy, so it switches to using a source called ‘ketones’ that are generated during fat metabolism.
So, how does this work? Let’s look at the Standard American Diet to see what is currently happening in your body:
- When you eat foods high in carbohydrates (especially sugars), the body either burns the glucose immediately or, your body secretes a hormone called insulin to remove the non-burned glucose from your system.
- Glucose is converted into glycogen and the muscles and liver are the main storage areas for glycogen. The liver stores about 400 Calories of glycogen, while the muscles store anywhere from 1400 – 2000 Calories.
- While this is all happening, your blood glucose crashes and you need more glucose to keep energy levels normal. So, how about a few chips, a candy bar, leftover pizza? They will bring the glucose back up – but, you repeat the cycle all over again.
- What happens to that extra glycogen that the muscles and liver can’t store? Well, once the liver and muscles are filled, the remainder is stored at fat. And, if that isn’t bad enough, elevated insulin hinders the ability of your body to use stored fat as energy.
- What does this mean? Your body thinks you are starving – despite the fact that your body has about 94,000 Calories of energy in fat deposits (more if you are overweight). So, think about this analogy (and thank you, Dr. Peter Attia as the source of this):
- The body is similar to a fuel truck. Like the truck – it is equipped with a small ‘gas tank’ (your glycogen stores). Yet, there are more than sufficient fuel reserves sitting in the tanker (for the body, this is in the form of stored fat).
- You have so much energy to use – but, the system can’t tap into it (just like the truck) because insulin levels remain high.
This is where ketogenic diets and keto-adaptation comes into play. By keeping your ingested carbohydrates low, your insulin decreases and the fatty acids in your cells now become available for fuel – and, a real positive side effect is that they generally decrease hunger as well.
So, what are ketones?
As I mentioned earlier, ketones are by-products of fat metabolism and are utilized by the body just like glucose. They can also be used by the brain and other organs for energy. Some organs (like the heart) actually prefer to burn ketones rather than glucose.
How do you get keto-adapted?
It takes ~ 2 – 3 weeks of low-glycemic eating to become keto-adapted. This is not to be confused with diabetic ketoacidosis which is life threatening. Diabetic ketoacidosis affects people who don’t produce insulin (Type 1 diabetics, or Type 2 diabetics that are dependent on insulin). This is different than the ‘nutritional ketosis’ I am discussing here.
During this transitional phase, the body enzyme structure changes as it begins to make more enzymes that are involved in breaking down fat (rather than storing glucose).
Are there negative side effects? I have only seen them during the transition phase where there might be fatigue, headaches, and some weakness – but, these clear up fairly quickly if you are consistent.
What does the diet look like? That is a topic for my next post.