Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

Ketogenic diet

8-minute read

Key facts

  • The ketogenic (‘keto’) diet is a low carbohydrate diet that uses ketones from the breakdown of fat as the main source of energy for your body.
  • For some people, the ketogenic diet is unsafe, for example for most children, if you’re pregnant or breastfeeding, for people with kidney disease or at risk of an eating disorder risk or if you are taking certain diabetes medicines.
  • The ketogenic diet may be tried by children with epilepsy who are still having seizures, but they need close supervision and nutritional supplements.
  • There is little evidence to support the use of a ketogenic diet for long-term weight loss.
  • Speak to your docotor before you start a ketogenic diet — you can also ask for a referral to a dietitan to find an eating plan that’s right for you.

What is the ketogenic diet?

A ketogenic (or ‘keto’) diet is a low-carbohydrate, high-fat diet. While it has benefits as a medical treatment for certain groups of people, there is little evidence to support it as a long-term weight loss diet.

When you are on a ketogenic diet, you eat a very small amount of carbohydrates, some protein and a high amount of fat every day. Your body breaks down fat into ‘ketone bodies’ (or ‘ketones’) as energy through a process called ketosis. Some parts of your body, such as the brain and red blood cells, need glucose to work and can’t use ketones for energy. The body will break down proteins from food or your muscle to make glucose.

What do you eat on the ketogenic diet?

On a ketogenic diet you usually eat only 20g to 50g of carbohydrates per day. As an example, 50g of carbohydrate is equal to 2 slices of bread and a banana. Carbohydrates make up about 10% of your daily intake in a ketogenic diet. This means your body breaks down fat for energy and stays in a state of ketosis.

What is a carbohydrate?

Carbohydrates, or ‘carbs’, are important nutrients. They are an excellent source of energy for the body and especially the brain. You need carbohydrates to avoid ketoacidosis — this is when ketone levels in your blood become dangerously high.

As well as energy, most foods that contain carbohydrates also give your body vitamins, minerals and fibre for good bowel health.

What should I expect on a ketogenic diet?

The main foods you will eat on a ketogenic diet include meat, fish, eggs, cheese, oils, cream, avocado and nuts. You may have some low carbohydrate vegetables, such as lettuce and cucumbers. On a typical ketogenic diet, you will have only small amounts of rice, pasta, fruit, grains, bread, beans and starchy vegetables such as peas and potatoes.

It can be hard for you to get all your daily recommended nutrients while following the ketogenic diet.

Ask your doctor or an accredited practising dietitian before you start a ketogenic diet, to ensure that it’s safe in your situation, and to ensure you get the right amount and types of fats, fibre and vitamins and minerals.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

What are the effects of a ketogenic diet?

A ketogenic diet will usually lead to weight loss in the short term. This may be because the diet is high in fat which keeps you feeling full for longer.

There are some possible short-term negative effects of a keto diet, including:

The ketogenic diet as a medical treatment

Epilepsy

The ketogenic diet can be helpful if your child has epilepsy and continues to have seizures while on antiepileptic medicines. Your child should only start a ketogenic diet if their neurologist recommends it, and with the support of a specialised dietitian. Your child will also need supplements to make sure they get all the vitamins and minerals their body needs.

Diabetes

If you have type 2 diabetes, a ketogenic diet may improve blood sugar management in the short term. However, the long-term effects are not known, and eating a high fat diet can increase your cholesterol levels.

Other conditions

There is no evidence that the ketogenic diet can treat or cure cancer. Speak to your doctor if you are thinking about a ketogenic diet for health reasons, as there are health risks, and the diet is not right for everyone.

The ketogenic diet for weight loss

The ketogenic diet is often promoted for weight loss in people with type 2 diabetes but research is not consistent. It can usually help in the first few months but the weight loss often doesn’t last. In overweight people without diabetes, short-term benefits have been seen but long-term effects need more research.

The ketogenic diet can be hard to maintain because it limits what foods you can eat. This means many people drop out of the diet. This can also contribute to unhealthy, ‘yo-yo’ dieting behaviour. The key to maintaining a healthy weight in the long-term is a healthy eating pattern that you can follow over time.

Risks of the ketogenic diet

Low carbohydrate diets such as the ketogenic diet can affect your child’s growth and should be avoided.

If you take insulin or certain medicines for your diabetes you may be at increased risk of having low blood sugar (hypoglycaemia) while following the ketogenic diet. There is a risk of diabetic ketoacidosis if you take certain medicines particularly the SGLT-2 inhibitors and follow the ketogenic diet.

It is also not recommended to follow the ketogenic diet if you:

When should I speak to my doctor?

Always speak to your doctor before you start the ketogenic diet to make sure it is the right choice for you. They may refer you to a dietitian to make sure that you get enough nutrients in your diet.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

Resources and support

  • Talk to your doctor to check if a ketogenic diet is right for you.
  • Find an accredited practising dietitian from the Dietitians Association of Australia, or call 1800 812 942.
  • Dietitians Australia have an example low carbohydrate menu to give you an idea of what foods you would be eating on a ketogenic diet.
  • Call the healthdirect helpline to speak with a registered nurse on 1800 022 222 (known as NURSE-ON-CALL in Victoria).
  • If you or your child is diagnosed with epilepsy, and want to check if a ketogenic diet is a good option:

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: September 2023


Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Low-carbohydrate diets for people with type 1 and type 2 diabetes | Dietitians Australia

If you’re thinking about starting a low-carb diet to manage your diabetes, here’s what you need to know.

Read more on Dietitians Australia website

Ketogenic Diet - Epilepsy Action Australia

The original ketogenic diet is is a special high-fat, low-carbohydrate diet that helps to control seizures in some people with epilepsy

Read more on Epilepsy Action Australia website

Helpful or just hype? A look at the Ketogenic Diet | Diabetes Australia

The ketogenic diet has risen in popularity as a way for people with diabetes to lose weight and manage BGLs.

Read more on Diabetes Australia website

Are low GI and low carb the same thing? | Diabetes Australia

Low carb eating is popular among people with diabetes. Research continues but it appears the short-term effects can help with BGL management.

Read more on Diabetes Australia website

Can your diet prevent and treat cancer? | Dietitians Australia

Diet alone is unable to treat or cure cancer. But there are diet and lifestyle strategies you can use to reduce your risk of developing cancer. Diet and exercise are also an important part of cancer treatment.

Read more on Dietitians Australia website

LiveLighter - Low-carb craze: Should we avoid carbohydrates?

We see endless weight loss diets suggesting that we ditch the carbs. These diets claim that cutting carbs will lead to weight loss, but is that the truth? And should we really be avoiding them?

Read more on LiveLighter website

The Ideal Low Gi Meal | GI Foundation

Home / Top Tips for Low Gi Living / The Ideal Low Gi Meal The Ideal Low Gi Meal What does the perfect low Gi diet look like? Ideally each meal should contain half vege or salad, a quarter lean protein and a quarter low Gi carbohydrates

Read more on Glycemic Index Foundation website

Gi and Carbohydrates | GI Foundation

Home / Gi Facts and Research / Gi and Carbohydrates Gi and Carbohydrates A low Gi diet focuses on the quality of the carbohydrate rather than the quantity

Read more on Glycemic Index Foundation website

Does diet affect the biggest killers of men and women differently? | The George Institute for Global Health

A new study on diet and leading causes of death finds that those on a low carbohydrate, low fat and high protein diet had a lower risk of early death, but a lower risk of cardiovascular disease only in men.

Read more on The George Institute for Global Health website

A Guide to Carb Exchanges | GI Foundation

Home / Top Tips for Low Gi Living / A Guide to Carb Exchanges A Guide to Carb Exchanges Counting carbohydrates is an effective way to better understand carbohydrate portions and manage intake for successful low Gi meal planning

Read more on Glycemic Index Foundation website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.