With advances in modern medicine, it is being increasingly realised that therapeutic diet planning is as important as the medical treatment of diseased patients-both acute and chronic. The patient is advised a specific intake of different nutrients, which have to be converted into exact quantities of food items of the patient’s personal choice. This process involves the prescription of various nutrients and modifying them according to conditions of obesity index, disease etc. Given the different nutrition values of various food items, matching of prescribed nutrients becomes an operational research problem. The conversion of food items into a menu of dishes requires heuristic rules and reasoning. This paper describes the development of an Expert System, the Nutrition Diet Programme (NDP) for therapeutic meal planning, which incorporates mathematical programming, databases, knowledge bases and expert systems techniques. The importance of such a comprehensive customised diet planning system need hardly be emphasized, particularly in view of large rural population with no access to medical help, as well as the wide spread food habits in different regions of the country. The design of NDP system, currently under DOS, is highly open ended and with little effort it can be ported across platforms as well as to countries.