The impact of the addition of toppings/fillings on the glycaemic response to commonly consumed carbohydrate foods

Objective: To investigate the influence of the addition of various toppings/fillings on the glycaemic response to baked potato, pasta and toast. Design: Randomised, repeated measures design. Setting: Oxford, UK. Subjects: Forty normal, healthy subjects ( 11 males and 29 females) were recruited to the study. Subjects were staff and students from Oxford Brookes University. Intervention: Cheddar cheese, chilli con carne, baked beans and tuna were added to baked potatoes, cooked pasta and toast to determine the effect on glycaemic response. Results: No significant difference was found among the various toppings and baked potato ( P = 0.06), pasta ( P = 0.06) and toast ( P = 0.39). However, the addition of toppings to a carbohydrate-rich food had a consistent lowering effect on glycaemic index ( GI). In particular, the addition of cheddar cheese to potato, pasta and toast reduced the GI of the test meal to a value that is considered to be low-GI ( 39, 27 and 35, respectively). This is particularly notable for potatoes, which, when eaten alone, had the highest GI value of all the staples. Conclusions: This study has shown that the addition of foodstuffs to the staples baked potato, pasta and toast had a consistent lowering effect on the GI value of that meal. These findings emphasise the importance of investigating the GI of composite meals. Sponsorship: British Potato Council.