Many different versions of low-carb diets have come and gone over the past several decades, but one carb-restrictive diet that’s been around for generations and is garnering significant attention today is the ketogenic diet. Far from a fad diet, the keto diet has actually been practiced safely since the 1920s, when it was first used by clinicians treating ill, obese, and epileptic patients.
The ketogenic diet is a very low-carb, very high-fat diet that has been shown to promote steady weight loss, increase energy, support cognitive health and hormonal balance, and help reduce risk factors for chronic diseases like high blood sugar, high blood pressure and high triglycerides.
When you follow a ketogenic diet your body goes into the metabolic state of ketosis:
In order to push your body into the metabolic state of ketosis – and then keep it there while your body produces ketone bodies that are used for steady energy – you need to get about 75% or more of your daily calories from dietary sources of fat. In the absence of carbs and glucose, your body relies on fat from your diet, along with your own stored body fat, to keep itself running, which means that weight loss can happen quickly and reliably.
In order to prevent or reverse symptoms tied to poor health, I recommend a holistic approach to the ketogenic diet. This means that the bulk of your calories on the keto diet should come from healthy, whole ketogenic foods that are high in fat, including olive or coconut oil, ghee, grass-fed butter, pastured eggs, grass-fed meat, avocado, nuts and fatty fish.
Foods like processed meats (bacon or salami), poor-quality meats from factory farm-raised animals, processed cheeses, farm-raised fish, foods with lots of synthetic additives and refined vegetable oils (canola, sunflower, safflower, etc.) should definitely be avoided. While they may be high in fat, they can also lead to adverse health effects.
Eating plenty of non-starchy, green vegetables will also be key to your success, as these types of veggies provide important vitamins, minerals, fiber and antioxidants. Try to include a handful or two with each meal. Just be sure to minimize or avoid starchy veggies like potatoes, beets and squash, which may make it harder to stay in ketosis.
One factor that makes the ketogenic diet very different from other low-carb diets is the fact that it incorporates less protein and more fat. The keto diet includes moderate, but not high, amounts of protein (about 15% of daily calories). Carbohydrates, meanwhile, are limited to just 5-10% of daily calories (or about 25-35 net grams per day).
Eating the right amount of macronutrients is important because this ensures you’ll get into a state of ketosis and actually produce ketone bodies, which are key for making you feel great physically and mentally, even as you severely restrict carbohydrate intake. Eating too much protein can cause some of the protein to be converted to glucose, which is counter-productive on the keto diet and can inhibit your ability to move into ketosis.
Thanks to the positive impact that fasting has on hormones, blood sugar regulation, inflammation levels and detoxification, intermittent fasting is a strategy that can help take your keto diet results to the next level. The keto diet and fasting pair together so well because ketone bodies actually have an appetite-reducing effect, making it easier to go longer periods without eating.
Fasting has been shown to help regulate the hunger hormones ghrelin and leptin, while also supporting insulin sensitivity and aiding in weight loss. You can practice intermittent fasting by limiting the amount of time you eat each day to a 4-9 hour window (meaning you’ll fast for 15-20 hours), or by trying alternate-day fasting, in which you reduce calorie intake by 75% 1-2 days per week.
While on the keto diet, be sure to drink plenty of water and hydrating liquids throughout the day, including herbal tea, fresh-squeezed vegetable juice, organic coffee, green tea and bone broth. You’ll also want to consume some salt – by using sea salt or Himalayan pink salt to flavor foods or by drinking salted broth – in order to get enough potassium, magnesium and other electrolytes. Electrolytes can help with digestion and cellular and muscular functions, while also supporting good quality sleep, energy and mood.
While the keto diet is very different from most standard low-fat diets that are recommended for weight loss, it’s still generally considered to be safe and health-promoting for most people. That being said, people who should not start the ketogenic diet (especially without first talking to a doctor) include anyone with a history of diabetes, liver or kidney disease, eating disorder(s) and any genetic defects that interfere with fat absorption, as well as women who are pregnant or nursing.
Some people will temporarily experience keto diet side effects while they transition into ketosis, but those symptoms typically subside within 1-2 weeks. Potential side effects (sometimes called the “keto flu”) can include headaches, low energy, cravings, weakness and brain fog.