The ketogenic diet is one of the most talked about and debated diet trends today. You’ve probably heard celebrities, athletes, and neighbors raving about the benefits of this dietary approach. Interestingly, the science backs up its rapid growth in popularity, as a ketogenic diet has been shown to have numerous health benefits for its adherents. The diet can reduce the risk of heart disease, improve glycemic control in both Type 1 and Type 2 diabetes, help individuals struggling with obesity lower their BMI, and even improve or control symptoms of debilitating neurodegenerative conditions like Parkinson’s and epilepsy. There is even some evidence to suggest that a ketogenic diet can play a role in the treatment of cancer! If it is implemented properly, adopting a ketogenic diet can be a very powerful tool in the fight against a variety of chronic diseases.
If you’ve recently made the decision to transition to a ketogenic diet or are exploring the possibility of a change, chances are you might currently find yourself in a world of confusion. What is ketosis? What are ketones? Can I really eat all the fatty foods I want? How can this possibly be good for me?
Allow me to address some of these questions.
While the ketogenic diet may sound “new,” it actually parallels the way many of our ancestors ate, before the advent of agriculture allowed for the domestication of staple crops like wheat and corn. Before the widespread emergence of these crops into the modern diet, which are high in carbohydrates and sugar (particularly in their most processed forms), our ancestors ate a wide variety of wild plants and animals and much less carbohydrate or sugar. This diet, naturally lower in carbohydrate, forced our ancestors’ bodies to burn fat for fuel as opposed to carbohydrates — the core goal of the ketogenic diet.
As a clinician, I have recommended the ketogenic diet both as a clinical intervention for patients suffering from a wide variety of ailments as well as a general suggestion for people looking to optimize their cognitive health. And while the diet is relatively easy to follow, there are a number of common misconceptions and lots of outright misinformation that one must be aware of. If you’re looking to incorporate a ketogenic diet into your lifestyle or just wanting to learn more, I’ve compiled a few tips for you here.
The central aim of the ketogenic diet is to push the body into a state of ketosis, where metabolism shifts from burning carbohydrates as the primary energy source to fat, or “ketone bodies.” These ketones are a special type of fat that serve as cellular “superfuel.” In order to achieve ketosis, one must consume a diet high in healthy fats and dramatically lower in sugar and carbohydrates. This allows blood sugar to drop to the point that glucose is significantly less available to the body to burn as a source of fuel. In the absence of glucose, the body shifts its focus to ketones for energy production. Ketosis not only burns fat—which supports weight loss and BMI reduction if in a calorie deficit—it also transitions the body’s energy source to what clearly turns out to be a better fuel. In fact, energy derived from burning fat is associated with a remarkable reduction in the amount of damaging free radicals in the body, in comparison to burning sugar.
Focus on net carbs
Maintaining a state of ketosis is as simple as following the same dietary parameters that got the body into that state in the first place. If you limit carbohydrates and sugars in your diet, your body will opt to burn the healthy fats you consume for energy. However, when cutting carbs from your diet it is very important to focus on limiting net carbs, which is simply the number of grams of total carbohydrates in a portion of food minus the grams of fiber. Constipation is a very common issue for new adherents to the ketogenic diet, and it is caused by foregoing fiber in an attempt to limit total carbohydrates. So to prevent constipation from derailing your ketogenic diet, simply make sure you consume adequate levels of fiber!
What About Fasting?
One of the most powerful tools available to individuals on the ketogenic diet is fasting. Caloric restriction forces the body to burn through all of its available carbohydrates. Therefore fasting serves as an excellent kick start for getting the body into ketosis. Furthermore, periodic fasting while the body is in ketosis helps maintain that state because it keeps carbohydrate levels in the body negligible. Not to mention, fasting has been practiced by many cultures for thousands of years, and has numerous health benefits, generally, and is an incredibly powerful tool for improving brain health, specifically.
Before you fast, consult your health care provider to ensure it is a safe exercise for you. After confirming you can safely fast, I recommend kicking off a ketogenic diet with a 24-48 hour fast, during which time you consume nothing but water—but make sure you drink plenty of it. Once your body is in ketosis and you shift to maintenance mode, I suggest fasting once or twice a year for the same period of time and with the same, water-only restrictions. While fasting can be challenging, especially in the beginning, if you stick with it you can reap huge benefits.
Which Fats are Healthy?
One of the easiest traps to fall into when starting a ketogenic diet is the assumption that all fats are healthy. It is not uncommon to see new adherents loading up their plates with industrially harvested bacon, exclaiming, “I’m keto, so it’s healthy!” In reality, because ketosis repositions ketones as your primary fuel source, ensuring you consume healthy fats becomes even more important on the ketogenic diet.
Similar to the recommendations I make in Grain Brain, a ketogenic diet should derive a majority of its calories from fat. However, the optimal macronutrient ratio will vary from person to person. Some will thrive on roughly 80% of calories from healthy fats and 20% from carbohydrates and protein. Others may do better in the range of 60 – 75% of calories from fat and slightly more protein. I encourage you to experiment to find what works best for you. To meet this goal, you must consume plentiful amounts of healthy plant and animal fats. Some good examples of healthy fats include:
- Plant-based: Organic avocado, organic extra virgin olive and organic coconut oil, nuts—excluding peanuts, which are a legume, and seeds from chia, flax, hemp and pumpkin plants.
- Animal-based: Organic grass-fed and finished beef, pasture-raised chicken, wild-caught fish, organic grass-fed butter, and full-fat live culture yogurt.
- Supplements: MCT oil and fish oil, ensuring they are USDA-organic, hexane-free, and non-GMO. One important thing to note: MCT oil delivers beta-hydroxybutyric acid (BHB), which is the most important ketone body, and its benefits can be gained without fasting or even carbohydrate restriction. While the full benefits of a ketogenic diet will only be realized if you adhere to the diet in its entirety, incorporating MCT oil into your current diet and supplementation is a good way to benefit from ketone bodies on a smaller scale.
Ensuring that you consume adequate levels of healthy fats is vital to the success of any ketogenic diet. Avoiding bad fats, like industrially-farmed meat, hydrogenated oils, and processed vegetable oils, is just as important to ensure that you provide your body with a suitable source of energy in lieu of carbohydrates.
To Meat or Not to Meat?
One of the central questions new adherents to the ketogenic diet must answer is whether or not they want to incorporate meat into their new diet. It is entirely possible to consume adequate levels of healthy fats whether you approach the diet as an omnivore or a vegetarian, so this decision is largely a personal one. However, if you choose to incorporate meat into your version of the ketogenic diet, it is crucial to ensure it is grass-fed, organic, and free of antibiotics. Furthermore, it is important to focus primarily on above-ground leafy vegetables, with meat serving as a side dish. An example of the perfect plate for a keto omnivore would be a sizeable portion of colorful, above-ground leafy vegetables covered with a healthy fat like olive oil, paired with a 3-5 oz serving of high-quality meat.
Avoiding the “Low-Carb Flu”
Arguably the most challenging period of transitioning to a ketogenic diet is the first few days as your body adjusts to the dramatic decrease in carbohydrate intake and your metabolism begins its shift to fat as its primary fuel source. It is not uncommon during this period to experience a lack of energy, irritability, ravenous hunger, and brain fog, symptoms commonly referred to as the “low-carb flu.” These uncomfortable symptoms arise because a ketogenic diet eliminates the spikes in blood sugar that follow carb-heavy meals, keeping insulin levels low (because it is no longer needed in response to said blood sugar spikes) and triggering the kidneys to excrete high levels of electrolytes—think sodium, potassium, and magnesium. Additionally, many people transition to a ketogenic diet from a standard, modern diet, which was likely rich in processed foods packed with sodium, so electrolyte levels drop simply because you aren’t getting enough sodium to replace that which you previously took in from processed foods. In the end, if you do not replace these excreted and/or missing electrolytes in your new ketogenic diet, it can ultimately lead to a drop in blood pressure and bring about the symptoms of “low-carb flu.”
Rest assured, not everyone experiences this side effect of the ketogenic diet and, if you do, it will abate on its own; furthermore, there are some simple preventative steps you can take to lower your likelihood of “catching” this flu. As you adopt a ketogenic diet, make sure you replace electrolytes, eat enough fat to meet your total caloric needs, drink plenty of water, and exercise as you are able. It’s very important, however, to ensure that you aren’t relying on sugary sports drinks to replace electrolytes, as all that added sugar will prevent your metabolism from entering ketosis. Ultimately, electrolytes play a crucial role in our health and many Americans do not consume them at adequate levels, so it is very important to monitor your intake of these nutrients regardless of whether or not you are an adherent of the ketogenic diet.
In the end, the “low-carb flu” should be viewed as a testament to the power of the ketogenic diet. After all, eliminating the pressure on your body to regulate the blood sugar spikes that follow “normal” meals is ultimately what leads to these symptoms!
The ketogenic diet is an incredibly powerful tool that can be wonderfully effective in treating a variety of health issues facing modern society. By allowing the body to burn fat for fuel, the ketogenic diet can not only lead to sustainable weight loss, but it actually pushes the body to use an alternative and potentially superior fuel source. If you are just starting a ketogenic diet, use the tips outlined above and stick with it; it can be a challenging transition, but there are many, many benefits of long-term adherence to this diet.
Want to learn more about the ketogenic diet? Then consider checking out my e-guide to this incredibly powerful dietary and lifestyle choice.
David Perlmutter, MD.
- 5 Things You Didn’t Know About The Ketogenic Diet
- Key Foods on a Ketogenic Diet
- Dr. Group’s Ketogenic Fast for Rapid Weight Loss
- Everything You Need to Know About Ketosis