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28th February, 20203 min read

What is the ketogenic diet?

Medical reviewer: Healthily's medical team
Author: Tomas Duffin
Last reviewed: 28/02/2020
Medically reviewed

All of Healthily's articles undergo medical safety checks to verify that the information is medically safe. View more details in our safety page, or read our editorial policy.

The ketogenic (or ‘keto’) diet was first developed over 100 years ago as a treatment for epilepsy.

Starving yourself for a short period of time was thought to reduce seizures because when you don’t eat, the body produces substances, called ketone bodies, which can help to correct abnormal nerve signals that may cause epilepsy.

But how the diet is used has evolved over time, and it’s now popular among those who want to burn fat.

When it comes to weight loss diets, low-carbohydrate and high-protein eating plans tend to dominate. But the keto diet is a little different - followers have to stick to low-carbohydrate and high-fat meals.

The diet has no shortage of celebrity fans, but a debate about its potential risks and benefits continues.

So is this diet safe, and is it right for you?

Weight loss benefits of the keto diet

Even though the keto diet is a popular way to lose weight, research into how well it works is lacking. A 2004 critical review of previous studies found some evidence that following a high-protein diet may be more effective for weight loss than a low-fat diet.

But this doesn’t mean that the high-fat keto diet is an effective way to lose weight, especially in the long term.

Health benefits of the keto diet

It’s sometimes said that the keto diet can improve conditions like heart disease, Parkinson’s disease, Alzheimer’s disease and even cancer, but there’s little scientific evidence to support these claims.

What has been more closely studied is the idea that the keto diet can help people with epilepsy that doesn’t respond to medication.

Findings from an 11-study review, published in the Cochrane Database of Systematic Reviews in 2003, suggest that the diet may reduce seizures and other symptoms of epilepsy. However, as these studies were fairly small in size (66 adults and 778 participants in total), the results can’t be taken as conclusive proof that the keto diet improves epilepsy symptoms.

Risks of the keto diet

The keto diet is a high-fat and low-carbohydrate diet. This means that a typical day on the diet involves increasing your fat intake and severely limiting how many starchy carbohydrates you eat.

Some fat is good for you, but eating too much saturated fat can raise your cholesterol levels and increase your risk of heart disease.

A 2019 scientific review, published in the journal Nutrients, also highlighted that as the keto diet involves cutting out lots of foods, it may put some elderly people at risk of not getting all the nutrients they need.

Is the keto diet right for me?

The keto diet has its risks and benefits, and as there’s no one-size-fits-all diet, it’s difficult to conclusively say who should or shouldn’t follow the ketogenic style of eating.

It’s worth bearing in mind that the keto diet requires a lot of commitment and you’ll need to restrict what you eat.

If you’re interested in the keto diet and would like more guidance on it, see a dietitian for advice.

Alternatively, if you’d like to know more about how to lose weight safely, read this article on how to diet.

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We include references at the end of every article, so you know where we get our facts. We only ever take evidence from medically-recognised sources, approved by the UK National Health Service's The Information Standard, or certified by Health On the Net (HON). When we talk about popular health trends or claims, we'll always tell you if there's very little or no evidence to back them up. Our medical team also checks our sources, making sure they're appropriate and that we've interpreted the science correctly.

Important: Our website provides useful information but is not a substitute for medical advice. You should always seek the advice of your doctor when making decisions about your health.

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