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

5-minute read

What is the ketogenic diet?

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

People on a ketogenic diet eat a very small amount of carbohydrates, a moderate amount of protein and a high amount of fat per day. This means that the body burns fat as its main source of fuel and breaks it down into ‘ketone bodies’ (or ‘ketones’) in a process called ketosis.

People on a ketogenic diet usually eat only 20g to 50g of carbohydrates per day or less. As an example, 50g of carbohydrate is equivalent to 2 slices of bread and a banana. Because carbohydrates make up about one tenth of daily kilojoule intake in a ketogenic diet (a kilojoule is a measure of how much energy we get from food), the person’s body stays in a constant state of ketosis.

Evidence shows that the diet may be suitable for some people with certain medical conditions, but there is very limited evidence that healthy people should use it as a long-term diet.

What is a carbohydrate?

Carbohydrates, or ‘carbs’, are an important nutrient. They are an excellent source of energy for the body and brain. Most foods that contain carbohydrates also provide vitamins, minerals and fibre for good bowel health.

What to expect on a ketogenic diet

A typical ketogenic diet significantly reduces a person’s intake of rice, pasta, fruit, grains, bread, beans and starchy vegetables such as peas and potatoes. For example, the Dietitians Association of Australia says that this could restrict you to the carbohydrate levels of only a small tub of yoghurt, a medium-sized potato and one apple a day.

Many Australians find it hard to meet the recommended daily intakes of wholegrains, vegetables and fruit a day. The Australian Dietitians Association says that being on a ketogenic diet can make it harder to reach these targets without supplements.

A ketogenic diet should always be followed in consultation with your doctor or an accredited practising dietitian, to ensure that you get the right amount and types of fats, fibre and vitamins, as well as minerals like calcium, magnesium, iron and potassium.

What are the effects of a ketogenic diet?

A ketogenic diet will usually lead to rapid weight loss. This may be due to water loss and because you get less hungry because the diet is high in foods containing fat and protein.

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

The ketogenic diet as a medical treatment

Evidence suggests that a ketogenic diet, under the supervision of a doctor or dietitian, is useful for children with epilepsy who continue to have seizures while on antiepileptic drugs. There is growing interest in its use in cancer, particularly in brain cancer, although more studies are needed on humans before this can be recommended.

For people who have type 2 diabetes, a ketogenic diet may improve blood sugar control in the short term. However, the long-term effects are not known, particularly on cholesterol levels, which increased in some studies.

The ketogenic diet for weight loss

The ketogenic diet is often promoted for weight loss in healthy people. It is often suggested for people with obesity

There have been only limited and small studies on the ketogenic diet for weight loss. These studies have shown that the diet has short-term benefits in some people including weight loss and improvements in total cholesterol, blood sugar and blood pressure, but at one year these effects are about the same as those of conventional weight loss diets.

While a ketogenic diet can be fast and effective in the short term, it can be hard to maintain because it is very limiting. This means a large number of people tend to drop out of the diet, contributing to unhealthy, ‘yo-yo’ dieting behaviour. The key to maintaining a healthy weight in the long-term is an eating pattern that you can sustain over time.

It is important to remember that people have different needs, and that no single weight-loss diet suits everyone. A ketogenic diet may be an option for some people who have had difficulty losing weight with other methods, but if you choose to go on a ketogenic diet, it is best to be under the supervision of a doctor and an accredited practising dietitian.

Resources and support

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

Last reviewed: May 2021

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

:: Ketogenic Diet - Epilepsy Action AustraliaEpilepsy 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

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

Frequently Asked Questions | GI Foundation

Frequently Asked Questions All your questions about low Gi answered

Read more on Glycemic Index Foundation website

Weight loss - common myths - Better Health Channel

There are no magical foods, or ways to combine foods, that melt away excess body fat.

Read more on Better Health Channel website

Reading Food Labels | GI Foundation

Home / Top Tips for Low Gi Living / Reading Food Labels Reading Food Labels To help work out the amount of carbohydrates (or number of exchanges) in a food and make low Gi choices, a basic understanding of food labels is important

Read more on Glycemic Index Foundation website

Low Gi Explained | GI Foundation

Home / Gi Facts and Research / Low Gi Explained Low Gi Explained Backed by more than 40 years of science, a healthy low Gi lifestyle is a sustainable way to improve overall good health across all stages of life

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 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.