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.
That’s why it’s recommended by so many doctors.
What is a keto diet?
The keto diet is a very low-carb, higher-fat diet. It’s similar in many ways to other low-carb diets.
While you eat far fewer carbohydrates on a keto diet, you maintain moderate protein consumption and may increase your intake of fat. The reduction in carb intake puts your body in a metabolic state called ketosis, where fat, from your diet and from your body, is burned for energy.
You can quickly learn more about the basic ideas behind the keto diet in this video course:
What “keto” means
A “keto” or “ketogenic” diet is so named because it causes your body to produce small fuel molecules called “ketones.”
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.
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 drop 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 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.
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.
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 ter
There are controversies 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, 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.
Try to avoid
Here’s what you should avoid on a keto diet – foods containing a lot of carbs, both the sugary and the starchy kind. This includes starchy foods like bread, pasta, rice and potatoes. These foods are very high in carbs.
The numbers are grams of net carbs per 100 grams (3.5 ounces), unless otherwise noted.
Also avoid or limit highly processed foods and instead follow our whole foods keto diet advice.
You should also avoid low-fat diet products. A keto diet should be moderately high in protein and will probably be higher in fat, since fat provides the energy you’re no longer getting from carbohydrate. Low-fat products usually provide too many carbs and not enough protein and fat.
What can you drink on a ketogenic diet? Water is the perfect drink, and coffee or tea are fine too. Ideally, use no sweeteners, especially sugar.
A splash of milk or cream in your coffee or tea is OK, but beware that the carbs can add up if you drink multiple cups in a day (and definitely avoid caffe lattes!). The occasional glass of wine is fine too.
While there is no strict definition of a low-carb diet, anything under 100–150 grams per day is generally considered low-carb. This amount is definitely a lot less than the standard Western diet.
You may achieve great results within this carb range, as long as you eat unprocessed, real foods.
But if you want to get into ketosis — which is essential for a ketogenic diet — then this level of intake may be excessive.
Most people will need to go under 50 grams per day to reach ketosis.
Keep in mind that this doesn’t leave you with many carb options — except vegetables and small amounts of berries.
Protein is a very important macronutrient which most people don’t get enough of.
It can improve feelings of fullness and increase fat burning better than other macronutrients (1Trusted Source).
Generally speaking, more protein should lead to weight loss and improved body composition.
However, low-carb dieters who eat a lot of lean animal foods can end up eating too much of it.
When you eat more protein than your body needs, some of its amino acids will be turned into glucose via a process called gluconeogenesis (2Trusted Source).
This can become a problem on very-low-carb, ketogenic diets and prevent your body from going into full-blown ketosis.
According to some scientists, a well-formulated low-carb diet should be high in fat and moderate in protein.
A good range to aim for is 0.7–0.9 grams of protein per pound of body weight (1.5–2.0 grams per kg).