A proportion of people with epilepsy continue to have seizures despite all conventional treatment options. The classical ketogenic diet and its variants have been shown to help some of these people. However, these diets require significant medical and dietician supervision,and is frequently not well tolerated. There is a need to develop other diet therapy that is easier to administer and more acceptable to the patient. This trial undertaken in adult overweight UCLH outpatients examines the effect of an intermittent fasting diet on seizures. Subjects may consume their normal diet for 5 days a week. On 2 days in a week, they consume only 25% of their daily calorie requirement. Subjects will continue on the diet for 6 months. Intermittent fasting has been shown in animal studies to activate a number of signalling pathways which are thought to reduce seizure thresholds. Has intermittent fasting in humans might be expected to reduce seizures.