Since its introduction in 1981, the glycaemic index (GI) has been a useful tool for classifying the glycaemic effects of carbohydrate foods. Consumption of a low-GI diet has been associated with a reduced risk of developing CVD, diabetes mellitus and certain cancers. WISP (Tinuviel Software, Llanfechell, Anglesey, UK) is a nutrition software package used for the analysis of food intake records and 24 h recalls. Within its database, WISP contains the GI values of foods based on the International Tables 2002. The aim of the present study is to describe in detail a methodology for adding and amending GI values to the WISP database in a clinical or research setting, using data from the updated International Tables 2008.