As a physician and educator, people frequently ask me what the best diet is for them. The problem is there are so many options that completely are opposite from vegan and low fat to paleo and primal to those in the middle such as Whole 30 and Mediterranean. Add in the latest diet program written by an expert and you can imagine how we are all confused.
The answer I tell everyone is it depends. It depends on your goals. It depends on your genetics. It depends on your gut microbiome. It depends on your activity level. And it depends on your commitment to making the food you put into your mouth a priority. Clearly an Inuit eats different than a Chinese farmer who eats different than somebody from Greece or Mexico.
As I have written to you in the past, the most important choice about foods is to avoid foods that are processed that contain empty calories and other “toxins”. After that you need to individualize. And that takes a bit of time and effort but once you nail it your diet will be yours for life!
However, there are times when eating a certain way can have therapeutic or performance purposes. By that I mean they are great to follow to address a health condition or enhance ability but may not meet your long-term needs.
One of these is the ketogenic diet.
Once touted for being restrictive, impossible, and even dangerous, this diet is now everywhere. What the ketogenic diet is—and what it’s not.
The ketogenic diet is known as a high-fat, moderate-protein and low-carbohydrate diet. This mean at least 80 percent of your total calories coming from fats. To accomplish this, you avoid foods like fruit, bread, pasta, crackers, cookies, sugar, tomatoes, milk, yogurt, and potatoes (just to name a few) and focus instead of eating avocados, olive oil, olives, salmon, butter, chia and flaxseeds, cruciferous vegetables, and nuts like walnuts, almonds, and macadamia.
The goal of an effective ketogenic diet is to maintain low serum blood glucose and high circulating blood ketones. The diet works by decreasing circulating glucose, which has several downstream effects, including decreased inflammation, increased energy, increased cognition and weight loss.
One thing is clear: It’s not the best fit for everyone. Compliance is a huge limiting factor, this diet can be a bit socially isolating, and for some people it can be hard to tolerate due to individualized GI side effects.
That said, there are certain groups or people that can definitely benefit from a ketogenic diet, including:
Originally, the main purpose of the diet was to help children who had uncontrolled seizure activity, despite being treated with anti-seizure medication. And people who are on anti-epileptic drugs can still benefit by going on the diet; they could even potentially reduce their dose of anti-seizure medications with the addition of the ketogenic diet.
How does this work, exactly? Think of your mind as an engine. When it gets flooded, seizures can happen. When you have low blood sugar and eat a high-sugar meal, sugar in the form of glucose floods into the brain and can create seizures. Those who consume a high-fat diet will experience steadier energy levels and less opportunity for “engine flooding.”
2. Type 2 diabetics
People with type 2 diabetes tend to have both high blood sugar levels and insulin resistance. This actually “starves” the cells of energy, which, in turn, creates a strong feeling of hunger. The ketogenic diet restricts blood glucose and allows the body to use ketones as its alternative fuel source. By doing this, the body naturally has lower blood glucose. When the body’s glucose is decreased consistently over time, it can help cells become “re-sensitized” to the insulin. This allows the body to better utilize its energy derived from glucose.
3. People who want to lose weight
For most individuals, the ketogenic diet is effective at facilitating weight loss. As with those with type 2 diabetes, reducing glucose and increasing ketones will enhance metabolism, enhance energy and decrease hunger. But it is important to know that when glucose is stored in the body, it’s stored as a molecule called glycogen. With each gram of glycogen that is stored, approximately 3 to 4 grams of water are stored with it. This means that when you’re eating a carbohydrate-restricted diet, such as a ketogenic one, your body uses its own glycogen stores to keep up with the body’s glucose demands during times of fasting or periods without eating food. This will lead to a large amount of water-weight loss when starting the diet.
By restricting carbohydrates to 20 grams of net carbs daily, weight loss can be quite rapid in the first few weeks of the diet. But this will also along with the consequential electrolyte shift—cause the body having to adjust to the secondary fuel source, ketones—and cause what some people call the “keto flu.” Symptoms include fatigue, stomach pain, fogginess, irritability, nausea, muscle cramping, and lack of concentration. This will pass.
4. People who have certain types of cancer
The newest topic regarding the ketogenic diet is in cancer and cancer therapies, especially in the case of brain tumors. This is due to the theory that cancer cells consume a large portion of glucose to supply the cells with the energy they need to grow. And we do know that cancer cells have an affinity for using glucose, which results in a dependence on glucose as an energy source. When eating a ketogenic diet, you end up decreasing the amount of blood glucose in the body, using ketones instead. This can help stop or decrease cancer cell growth and movement.
The research of Dr. Adrienne Scheck and Dr. Angela Poff, two pioneers in the field of ketogenic diets and brain tumors, has shown very positive effects of the keto diet in mice with brain tumors. In one study, the mean survival time was increased 56.7 percent in mice with metastatic cancer who followed the ketogenic diet. They have also looked at how the ketogenic diet may sensitize cancer cells to the effects of radiation therapy and chemotherapy. In mouse models of glioma, the ketogenic diet demonstrated a synergistic effect, working together with radiation and chemotherapy to make it more effective. There is also ongoing promising research into the health benefits of intermittent fasting and Fasting-Mimic Diets into cancer prevention and synergistic cancer treatment,
Most people think that they must consume carbohydrates to be a competitive athlete, but this isn’t always the case. When you’re eating mostly carbohydrates (which means 50 percent of your total calories or more coming from grains, fruits, and veggies), you are considered a “glucose burner.” But if you are lean, you have fewer glucose reserves to tap into when food intake is sparse. That means that to participate in a physical activity, you must always have a steady source of fuel in order to maintain optimal performance and keep up with energy demands. A high-carbohydrate diet ensures that glucose and carbs are the dominant fuel source for the exercise. When your reserve tank decreases, so does performance.
When you are in a state of ketosis, however, your body is not dependent on carbs or glucose for your cells to make and sustain energy. When you’re following a ketogenic diet and are fat-adapted (meaning you have been in ketosis and maintaining that state for quite some time), you can use your ketones as fuel instead or glucose.
Two top researchers in the field of low-carb and performance, Dr. Jeff Volek and Dr. Stephen Phinney, have shown that when fuel is scant, the body can tap into its own adipose, or fat tissue, to keep the engine going for longer and steadier periods of time. After this transition, your body can train harder, recover faster, and stay active for longer. Their studies have also shown that muscle proteins are the last to be broken down, which means the ketogenic diets will spare your muscles and still be able to sustain you.
But it is important to know that ketosis works best for longer slower endurance activities as we do need the quicker fuel from carbohydrates for activities that require power and sprinting. You can still perform well in ketosis but those competing at the top end will see performance suffer.
Keto isn’t a diet that benefits everyone or is a panacea for all diseases and health problems, but the results from people who have the conditions listed above and those that are getting results are intriguing. Another important point is you don’t need to stay on for a lifetime, you can follow for a period of time and then gradually as your body and physiology come back to a more optimal state of health find your set point where you can add more carbohydrates without suffering any setbacks.