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.