- Protocol (Ad Libitum Study): After completing the metabolic phase of the study, the thirty subjects will be asked to continue with the diet to which they were randomized for a further 6-month period. During this ad libitum trial, study foods will not be provided. This longer less tightly controlled study will establish the value of this diet in "real life" situations. This will be required to support our shorter term, well-controlled more detailed metabolic study. Fasting weight will be taken at monthly intervals together with blood pressure and blood for lipids, glucose and insulin assessment.