Is a keto diet the best way to lose weight?

Your body uses whichever energy source is most readily available. This is normally glucose (sugar) converted from carbohydrates. If you drastically limit your carbohydrate consumption and replace it with fat, your body is eventually forced to use fat from food or your stores as energy instead. This process is called ‘ketosis’. “It is essentially the Atkins diet repackaged and renamed”, says Medlin.

“Most people calling their diet ‘keto’ are simply following a low or very low-carbohydrate diet”, she continues. The degree to which you need to restrict carbohydrates to be in ketosis “varies from person to person”, she adds. In a clinical or therapeutic setting, such as for children with epilepsy, the diet is designed specifically for the individual and support and monitoring are provided.

Low-carb, high-fat ingred ients include avocados, meat, fish, eggs, cheese, cream, oil, butter, nuts and seeds. But not all ingredients need to be high in fat â€" leafy greens and berries are often included, for example. You avoid, or at least heavily restrict, wheat and other grains, potatoes, corn, pulses, beans, milk, most fruit and sugar.

To induce ketosis, a maximum of 20â€"50g carbohydrates can be consumed daily for someone eating 2,000 calories a day, according to a 2019 paper on the ketogenic diet. To put this into perspective, a banana contains about 20g and a plain bagel 44g. Protein is also usually kept to a moderate amount, as it can encourage the production of glucose and interrupt ketosis.

The keto diet has few rules on which high-fat foods to eat, and ‘dirty keto’ can consist of bacon and sausages fried in butter, as this technically meets the criteria. Medlin says the healthy eating guidelin es should always roughly apply, even if you limit carbohydrates and regardless of what diet you're following.