While reading Jimmy Moore and Dr. Westman’s Keto Clarity, I started pondering on this. Most of us know that reducing carbohydrate intake (especially simple sugars) is very beneficial to one’s health, but if you are following a low-carb diet and you are not in ketosis, there may be some issues.
If you consume, say, 100-150g of carbs a day, much of it will be used by the brain , while the remainder will be insufficient to supply for the energy demands of the rest of the cells throughout your body.
In this situation, you’re not producing ketones (because of the higher carbohydrate intake) to supply for the energy demands of the brain and most of the cells. No wonder the fatigue and light-headedness you’d experience.
Low-Carb vs. Keto
When you eat low-carbohydrate but you do not go low enough to become ketotic, you’re still a sugar burner (and a very inefficient one) and you’re likely to fall of the wagon because you do not experience the benefits of ketosis.
When you’re doing low-carb and you are not ketotic, some of your body’s cells will use fatty acids for energy indeed, but your brain cannot use them directly as they cannot cross the blood-brain barrier.
Cravings and hunger are most likely to occur under this protocol as your cells will scream at you to give them sugar. The foggy mind may be persistent.
Note that this type of scenario can happen when you are very-low-carb and eat high-protein. You’ll not be able to enter ketosis due to gluconeogenesis (GNG) – synthesis of glucose mostly from protein substrates.
This will also occur when you’re just starting out a ketogenic diet because your body needs time to accommodate to switching to primarily burning fat for energy instead of glucose. It also needs time to start to efficiently use ketone bodies as energy sources.
It takes time because more mitochondria will be created to support the fat metabolism [2, 3]. Besides, a predominant fat metabolism requires higher enzymatic support.
That’s why I think ketosis is a permanent desired state as long as the feeding pattern is well formulated.
You can do a simple web-search and find thousands of studies on low-carb diets, some of them being poorly conducted and interpreted, while others would resemble real inefficiencies of low-carb diets.
Finding good studies on ketogenic diets is also challenging because folks from the research community confuse well-formulated ketogenic diets (where you don’t have to use multivitamin pills and supplements – see Wahls Paleo Plus or Phinney and Volek’s perspective) with diets that are high in fat and poor in nutrients, high in fat and carbs, high in fat and protein or other poorly designed version of diets high in fat.
I consider that being on a low-carb diet (and not being ketotic) is like being between metabolisms: you’re not efficiently burning sugar because you don’t have enough and you’re not in ketosis to burn fat primarily). This also happens if you go in and out of ketosis (note for carb-cycling and carb-loading). You never become keto-adapted to experience all the benefits of this state. From a biochemical perspective, insulin is the master orchestrator here.
However, these situations are better than following a high-carb diet.
Ketosis is Different
I honestly encourage you not to believe me. Learn how to efficiently read studies, read The Wahls Protocol, read the studies of Dominic D’Agostino regarding ketogenic diets for treating cancer as well as their use as tools for enhancing SEAL’s training and performance. Read Phinney and Volek’s book, read Keto Clarity by Jimmy Moore and Dr. Eric Westman. And most importantly, watch Volek’s presentation on keto-adaptation.
Ketosis is a desired state as long as your nutrition is well formulated. I’m talking about a nutrient rich keto-diet and not a diet that’s 85%+ fat, which is supplemented with multi-vitamins and minerals. If you don’t have a medical condition requiring such drastic strategies and if you’re a healthy person, a diet high-in-fat-moderate-in-protein-low-in-carbs which promotes ketogenesis (production of ketone bodies) and is nutrient rich would be preferable.
Once again, ketosis should not be a state in which you constantly get in and out because you never become keto-adapted to harness benefits such as extensive energy levels, clear mind, no hunger, and no cravings, as well as enhanced physical performance. One may know they are keto-adapted when they can perform well physically both in endurance and strength training while they are in ketosis.
Producing ketone bodies will make your brain use them in proportion of at least 70%  – see the image at the top of the post. They will efficiently be used by your heart, liver, and muscle, as well as most of the cells in your body.
There is no magic number for carbohydrate intake to trigger ketosis, but as Jimmy Moore put it in Keto Clarity:
1. Start at 20g of carbs per day and stick with that for a couple of days
2. If you’re in ketosis, you can increase your carb intake by 5-10g per day up to the point where you see ketone production starting to decline. That’s how you find your personal threshold.
3. If you’re not in ketosis with 20g of carbs per day (less likely), then reduce carb intake even lower. As your body starts recovering its insulin and leptin sensitivity you’ll be able to increase your carbohydrates to more sustainable levels.
Many of my friends and people who I talk to are going in and out of ketosis often and for different reasons. Folks, that’s not okay! You’re in-between if you do this and you may only cause yourself a lot of stress. Better not try doing this if you can’t do it well. I know you’re gonna hate me for this, but it is what I currently think.
1. El Bacha, T., Luz, M. & Da Poian, A. (2010) Dynamic Adaptation of Nutrient Utilization in Humans. Nature Education 3(9):8
2. Bough, K. J., Wetherington, J., Hassel, B., Pare, J. F., Gawryluk, J. W., Greene, J. G., … & Dingledine, R. J. (2006). Mitochondrial biogenesis in the anticonvulsant mechanism of the ketogenic diet. Annals of neurology, 60(2), 223-235.
3. Bénit, P., & Rustin, P. (2012). Changing the diet to make more mitochondria and protect the heart. Circulation research, 110(8), 1047-1048.
4. Phinney and Volek – The Art and Science of Low Carbohydrate Living
5. Maria Emmerich – Keto-Adapted
6. Jimmy Moore and Eric Westman – Keto-Clarity
7. Terry Wahls – The Wahls Protocol
8. Longo, V. D., & Mattson, M. P. (2014). Fasting: Molecular Mechanisms and Clinical Applications. Cell metabolism, 19(2), 181-192.