You may have heard about the high fat, low carb diet known as the ketogenic diet? The ketogenic diet can have a powerful impact when it comes to losing weight. For years fat has been demonised to be bad for our health and was considered the biggest contributor to weight gain. Numerous flaws in the ‘science’ that supported the low-fat diet have since been uncovered and huge amounts of evidence supporting the contrary had previously, been overlooked. All the while sugar was the secret enemy. After 50 years of false information no wonder this belief is still deeply ingrained in the minds of a lot of people.
So how does a high-fat diet work?
A ketogenic diet is simply a high, healthy fat diet (see my article here and here on fats for more info) with some protein and very low carbohydrate which limits which fuel sources the body can burn for energy. When the body only has the option to burn fat the process of ketogenesis begins. Ketogenesis is in fact the body’s natural response to starvation. Once the body has used up all of its reserves of glucose (sugar) from carbohydrate sources, its converts protein from our muscles into glucose to fuel the brain. This is not a good long-term solution because we need our muscles as well as our brain so the body then switches to the production of ketones. Ketones are made from stored fat in the body that is released in response to the shortage of carbohydrates and they are the perfect fuel for the brain and the muscles. Of course the body still needs a small amount of glucose on a daily basis which can be obtained from protein, that’s why it’s so important when going high fat to eat plenty of protein.
Why eat more fat?
Because we are, in effect, activating the starvation response which is not pleasant or sustainable for very long. Now that we understand to produce ketones for energy we can only eat limited carbohydrates with fat, we eat more fat with protein. Lowering or limiting the carbs we eat activates the switch to burn ketones and eating more fat stops hunger and allows us to feel satisfied after our meal or snack. Obviously it’s very important which types of fat you eat. The wrong type of fat could cause all sorts of health issues. Following this protocol trains the body to use stored body fat and the fat we eat for fuel and this is how we lose weight whilst eating healthily and feeling satiated.
A healthy ketogenic diet includes lots of protein and fat from white meat, occasionally grass-fed red meat, fish, eggs, raw nuts, seeds, cream, butter, cheese, and full-fat milk. Green leafy vegetables such as cauliflower, cabbage, broccoli, and Brussel sprouts along with natural plant oils from coconuts, avocados, and olives. This protocol can easily be done if you are vegetarian, vegan may be a bit more challenging. It is important that you ensure you eat enough protein. Macronutrient ratios for this protocol would look something like 65-80% of your calories from fat, 20-25% from protein and 5-10% from carbohydrate. The exact percentage will vary from person to person so you have to find what works for you within the suggested ranges.
This is not to say the ketogenic diet is to be followed continuously. In the form of a cyclical eating regime with a low GL eating protocol, this can really pack a punch when it comes to weight loss. Switching your primary fuel sources in this way helps your body to become metabolically flexible and highly efficient at using low GL carbs and healthy fats to burn body fat and keep it off.
Metabolic Autophagy by Siim Land
The Hybrid Diet by Patrick Holford