The first visit will involve screening tests for suitability for inclusion in the study and written, informed consent will be obtained. Weight, height and blood pressure will be measured and a 5ml blood sample will be collected for full blood count, urea, electrolytes and random blood glucose assessment. Subjects will be asked to complete questionnaires regarding general health, eating habits, mood and medical history. Following the screening visit, subjects will be asked to record their habitual food intake and physical activity pattern for a 3 day period (2 weekdays and 1 weekend day. They will then attend the laboratory on 6 further occasions, once for a familiarisation visit and for the 5 study visits.