Determination of the glycaemic index of various staple carbohydrate-rich foods in the UK diet

Objective: To determine the glycaemic index (GI) of various staple carbohydrate-rich foods in the UK diet, and to consider the factors influencing the GI of foods. Design: Subjects were served with 25 or 50g portions of glucose on three occasions, followed by a selection of test foods providing an equal amount of available carbohydrate, in random order. Each test food was consumed by 10 subjects. Capillary blood glucose levels were measured in the fasted state and over the 120 min following commencement of consumption of the foods. Setting: The study was carried out in a research institute (MRC Human Nutrition Research, Cambridge, UK). Subjects: Forty-two healthy adult volunteers were studied. Methods: The GI values of 33 foods were measured according to the WHO/FAO recommended methodology. These foods included various breads, breakfast cereals, pasta, rice and potatoes, all of which were commercially available in the UK. Conclusions: The results illustrate a number of factors which are important in influencing the GI of a food, highlighting the importance of measuring the GI of a food, rather than assuming a previously published value for a similar food. This is useful both to researchers analysing dietary surveys or planning intervention studies, and also to health professionals advising individuals on their diets.