The influence of sex on glucose and insulin responses in patients with non-insulin-dependent diabetes was studied in 12 men and 11 matched women. Two meals of either 100 g white bread or 60 g (raw weight) white rice were given. Blood glucose response areas to white bread (517 vs 509 mmol/L) and to rice (306 vs 353 mmol/L) over a 300-min observation period were similar in females and males, respectively. Insulin responses showed an identical pattern to that of glucose in females and males--35784 vs 28230 pmol/L after white bread and 28044 vs 19464 pmol/L min after rice (NS) over a 300-min observation period, respectively. Within the two study groups, blood glucose-response areas to white bread were significantly higher than those to rice (P less than 0.05), whereas there were no differences in insulin-response areas within or between the two groups. The glycemic index of rice for females (62 +/- 9; mean +/- SE) and males (66 +/- 5) was similar.