A keto or ketogenic diet is a low-carb, moderate protein, higher-fat diet that can help you burn fat more effectively. It has many benefits for weight loss, health, and performance, as shown in over 50 studies.1 That’s why it’s recommended by so many doctors.2
A keto diet can be especially useful for losing excess body fat without hunger and for improving type 2 diabetes
What “keto” means
A “keto” or “ketogenic” diet is so named because it causes your body to produce small fuel molecules called “ketones.”5 This is an alternative fuel source for your body that can be used when blood sugar (glucose) is in short supply.
When you eat very few carbs or very few calories, your liver produces ketones from fat. These ketones then serve as a fuel source throughout the body, especially for the brain.6
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.7
On a ketogenic diet, your entire body switches its fuel supply to run mostly on fat, burning fat 24-7. When insulin levels drop very low, fat burning can increase dramatically. It becomes easier to access your fat stores to burn them off.8
This is great if you’re trying to lose weight, but there can also be other benefits, such as less hunger and a steady supply of energy — without the sugar peaks and valleys that often occur when eating high-carb meals. This may help keep you alert and focused.9
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 consistently fast forever.10
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 long term.11
Who should NOT do a ketogenic diet?
There are controversies and myths about a keto diet, but for most people it appears to be very safe.12 However, three groups often require special consideration:
- Do you take medication for diabetes, such as insulin? More
- Do you take medication for high blood pressure? More
- Do you breastfeed? More
For more details about pros and cons in different situations, check out our full guide: Is a keto diet right for you?
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. Full disclaimer
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.