Low-carb and Paleo nutrition approaches share many similar traits to a ketogenic diet. In fact, with only a few modification to your low-carb diet make it possible to achieve the best of both worlds. (Warning... If you're on a high carb diet, it will be a dramatic and often difficult transition. Try low-carb first for 8-12 weeks, then you'll be ready to take the plunge into a ketogenic diet).
The physiology of a ketogenic diet is incredibly interesting and a "keto" diet has significant benefits for a myriad of chronic health conditions including weight gain, diabetes, metabolic syndrome, cardiovascular disease, neurological conditions and certain cancers.(1,2)
Now, the practical part… How can you transform your current diet into a ketogenic Paleo approach?
#1 Reduce Your Carb Intake
If you’re following a Paleo or low-carb dietary approach, you’re likely already eating a moderate to low-carb diet, so it will probably be easier than you think to reduce your carb intake a little further to begin the shift into a ketogenic state.
Root Veggies vs. Cruciferous Veggies
The general guideline for carb intake on a ketogenic diet is 30-50g per day.(3) Practically speaking, this usually involves shifting from starchy carbs and root vegetables to cruciferous veggies and leafy greens. For example, one cup of sweet potato provides 27g of carbs, while 1 cup of broccoli yields only 6g. Starchy, carb-dense veggies can also be swapped out for leafy greens like arugula, spinach, mustard greens, etc. which carry minimal amounts of carbs.
Figure 1.0 – Carbohydrate in Root & Cruciferous Vegetables
Reduce Fruit Intake – Swap Out for Berries
Fruit is tremendously nutrient-dense. However, it can pack a significant carb punch. From an evolutionary perspective, our ancestors’ intake would likely have plummeted after the fall and throughout the winter months. On a ketogenic diet, you want be able to eat large amounts of fruit, but you can tweak your fruit selection to reduce total carb intake.
The following is a list of possible “swaps” to reduce your intake of carbs from fruit.
Figure 2.0 – Carbohydrate in Fruit
#2 Increase Your Healthy Fat Intake
A ketogenic diet emphasizes a robust intake of healthy dietary fat – approximately 70% of your total caloric intake.(3) This can seem a little daunting for some (especially those still fearful of dietary cholesterol). Here’s a breakdown of how to add healthy Paleo-friendly fats into your diet.
Saturated Fats – MCTs
Medium-chain triglycerides (MCTs) are a group of saturated fats that play a key role in supporting energy and vitality on a ketogenic diet. MCTs are absorbed directly into the bloodstream as free fatty acids via the portal vein (attached to albumin) and thus, unlike other fats, are ready to be converted to ketones by the liver to be used for energy (with no impact on insulin levels), All other long-chain fats are reformed into triglycerides and packaged into chylomicrons that travel through the lymphatic (immune) system before being released into circulation.
MCTs are naturally found in coconut oil (approximately two-thirds of the fat content) and are also a popular supplement. You can use coconut or MCT oil to cook your food, add it to a high-fat and -protein breakfast smoothie, or blended in your morning coffee or tea. Other key saturated fats include egg yolks, as well as duck fat or beef tallow for cooking food at higher temperatures.
#3 Modify Your Protein Intake
If you’re already following a low-carb diet, you’ll likely not need to change your protein intake. A common misconception is that a ketogenic diet is a high protein diet. In reality, if you consume too much protein on a ketogenic diet it will kick you out of ketosis (as amino acids are converted into glucose).(4) The general recommendation is to consume about 0.7-0.9g per pound bodyweight.(5) That’s about 100g for a 125lbs. adult. If you’re active and following a high-proteindiet start by adjusting your carbs and fat intake, then adjust protein intake if needed.
How Do I Know I’ve Reached Ketosis?
A simple urine test, using the standard urinalysis “dipstick” provided by your local pharmacy, will highlight when ketones are present in your urine. Test seven and 14 days after starting your diet. It’s a quick and easy way to assess your progress. If you become more dedicated to a keto approach as a dietary lifestyle (and it is indeed a "lifestyle"), then you can think about using “keto-strips” to assess your blood levels of ketones. (This is costlier but typically more beneficial once you’ve been in ketosis for some time.)
How Will I Feel on A Ketogenic Diet?
When you start a ketogenic diet, it will typically take about two weeks for you to become “fat-adapted” and experience the acute benefits of a keto approach. Some of the benefits are sustained energy throughout the day (no more energy crashes at 3h00pm), improved mental clarity (say goodbye to brain fog), weight loss, and improved base aerobic fitness. That said, the first two weeks may be a struggle.
As your body adapts to burning fat as a primary fuel source, you may feel periods of fatigue, poor concentration and reduced exercise capacity. While these symptoms are common, the severity depends on the individual.
The term metabolic flexibility describes the body’s ability to easily switch from primarily burning carbohydrate for fuel, to burning fats for fuel. The fitter and healthier you are, the more metabolically flexible, and thus the easier it should for you to make the shift to a keto diet.
If you’re overweight, out of shape, or eat a high-carb diet, then the symptoms may be more pronounced. But that shouldn’t necessarily shy you away from trying a ketogenic diet for short period. It can powerfully improve blood sugar and insulin levels, promote weight loss, improve cardiovascular health, and possibly have an “anti-aging” effect on your brain.(6-8) It will likely do you some good!
How Long Should I Be in Ketosis?
From an evolutionary perspective, our hunter-gatherer ancestors would have entered a state of ketosis periodically throughout the year as they scavenged for food or during the winter months when food sources were scarce. Ancestrally, our bodies are hard-wired to be able to enter and exit the state of ketosis. So, it’s not surprising that new research is uncovering a myriad of health benefits. It can be highly beneficial to go “keto” periodically throughout the year.
Some people feel so good on a ketogenic diet they decide they want to adopt a ketogenic diet full-time. While there is no current evidence that this is harmful for the body, there is some literature showing abnormally high levels of HDL cholesterol, which may be associated with adverse heart and kidney health.(9,10) For this reason, I would recommend 2-4 week ketogenic cycles, anywhere from 1-6 times per year.
The Keto-Paleo Diet… Final Word
Transforming your diet into a keto approach is actually quite simple; ramp up your fat intake, dial down the carbs, and modify your protein intake to suit your activity level (i.e. active vs. sedentary). From an ancestral perspective, short periods of ketosis are consistent with human evolution and have been shown to be have many health benefits.(8) Is a ketogenic diet right for you? Try it out and find out for yourself!
Dr. Marc Bubbs ND, CISSN, CSCS
Want to learn more? Listen to expert Ryan Lowery PhD(c) talk basic os a keto diet and impacts on health in Episode #33 of the Dr. Bubbs Performance Podcast...
Check out more articles in the "KETO" SERIES...
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 Freeman JM. (Mar-Apr 2013). Epilepsy’s Big Fat Answer. Cerebrum. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3662214
 Paoli A, et al. (2013). Beyond weight loss: a review of the therapeutic uses of very-low-carbohydrate (ketogenic) diets. European Journal of Clinical Nutrition, 67. Retrieved from http://www.nature.com/ejcn/journal/v67/n8/full/ejcn2013116a.html
 Volek, J. Phinney, S. (2012) Art & Science of Low Carb Eating. Beyond Obesity LLC.
 Veldhorst, M et al. (2009) Gluconeogenesis and energy expenditure after a high-protein, carbohydrate-free diet. Amer J Clin Nutr 2009;90:519-26.
 Volek, J. Phinney, S. (2012) Art & Science of Low Carb Performance. Beyond Obesity LLC.
 Owen OE, et al. (Mar 1969). Liver and kidney metabolism during prolonged starvation. The Journal of Clinical Investigation, 48(3). Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/5773093/
 Grady D. (Aug 17, 2012). George F. Cahill Jr., Diabetes Expert, Dies at 85. The New York Times. Retrieved from http://www.nytimes.com/2012/08/17/health/george-f-cahill-jr-diabetes-expert-dies-at-85.html
 Paoli A, et al. (2011). [The ketogenic diet: an underappreciated therapeutic option?]. La Clinica Terapeutica, 162(5). Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22041813
 Shotji et al. Elevated Non-high-density Lipoprotein Cholesterol (Non-HDL-C) Predicts Atherosclerotic Cardiovascular Events in Hemodialysis Patients. Clin J Am Soc Neprhol. 2011 May;6(5): 1112-1120. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3087778/
 Ejida, Y et al. Serum non-high-density lipoprotein cholesterol (non-HDL-C) levels and cardiovascular mortality in chronic hemodialysis patients. Clin Exp Nephrol. 2012 Oct:16(5):767-72. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/22374049