The keto diet is a very low-carb and high-fat diet. It’s similar in many ways to other low-carb diets.

While you eat far fewer carbohydrates, you increase your intake of fat. The reduction in carb intake puts your body in a metabolic state called ketosis, where a lot of fat is burned for energy.

You can quickly learn more about the basic ideas behind the keto diet in this video course:

 

 

 

 

What “keto” means

 

The “keto” in a ketogenic diet comes from the fact that it allows the body to produce small fuel molecules called “ketones.”

​

 This is an alternative fuel source for the body, used when blood sugar (glucose) is in short supply.

Ketones are produced if you eat very few carbs (that are quickly broken down into blood sugar) and moderate amounts of protein (excess protein can also be converted to blood sugar).

The liver produces ketones from fat. These ketones then serve as a fuel source throughout the body, especially for the brain.

The brain is a hungry organ that consumes lots of energy every day, and it can’t run on fat directly. It can only run on glucose… or ketones.

​

​

On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels become very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off.

​

 This is great if you’re trying to lose weight, but there are also other less obvious benefits, such as less hunger and a steady supply of energy (without the sugar peaks and valleys we can get from high carb meals). This may help keep you alert and focused.

​

When the body produces ketones, it enters a metabolic state called ketosis. The fastest way to get there is by fasting – not eating anything – but nobody can fast forever.

​

A keto diet, on the other hand, also results in ketosis and can be eaten indefinitely. It has many of the benefits of fasting – including weight loss – without having to fast.

​

​

Who should NOT do a ketogenic diet?

There are controversie and myths about a keto diet, but for most people it appears to be very safe.

 However, three groups often require special consideration:

• Do you take medication for diabetes, e.g. insulin? M 

• Do you take medication for high blood pressure?

• Do you breastfeed? 

Are you a doctor or do you need your doctor to help you with medications on a keto diet? Have a look at our low carb for doctors guide.

 

Disclaimer: While the ketogenic diet has many proven benefits, it’s still controversial. The main potential danger regards medications, e.g. for diabetes, where doses may need to be adapted (see above). Discuss any changes in medication and relevant lifestyle changes with your doctor. 

 

This guide is written for adults with health issues, including obesity, that could benefit from a ketogenic diet.

Controversial topics related to a keto diet, and our take on them, include saturated fats, cholesterol, whole grains, red meat, whether the brain needs carbohydrates and restricting calories for weight loss.