Recent studies have shown that a keto diet not only produces significant weight loss, fast, but also has myriad other benefits for long term health. It is an approach that naturally compliments Dr Michael Mosley's Fast 800 programme. But it must be done the right way. Dr Mosley presents the latest science on the ketogenic diet - a diet high in fat and protein and very low in carbs - explaining how it works and why it is so good for you. The aim of a keto regime is to put yourself into ketosis, whereby your body goes from burning sugar to burning fat for fuel. This process of 'flipping the metabolic switch' has the added advantage of making you feel less hungry, which makes the diet highly motivating and relatively easy to sustain.