Subjects will be provided with a menu of foods to consume as their evening meal prior to study visits, based on 30% total energy expenditure. This meal will be based on foods the subject recorded in the completed food diary and will contain approximately 15% of total energy from protein, 55% from carbohydrate and 30% from fat. Before study visits subjects will be instructed to consume this standardised meal as their last meal of the day before 20.00 on the previous evening. After they have consumed this meal they are instructed not to consume any foods or drinks apart from water until they arrive at the lab.