Objective: To test the hypothesis that replacing starch with sugar in a processed breakfast cereal that has a high glycaemic index could significantly decrease glycaemic and insulin responses.
Design: Subjects consumed in random order three equi-carbohydrate meals based on a popular puffed rice cereal containing three levels of sucrose (0, 21 and 43 g). Postprandial glucose and insulin responses were compared using the incremental area under the curve (AUC).
Subjects: Twelve healthy volunteers (5 males and 7 females) with normal glucose tolerance drawn from the university community, mean age 23 years (range: 20 to 27 year), mean body mass index 22.6 kg/m2 (range: 18.6 to 31.2 kg/m2).
Results: Glycaemia was significantly lower after the meal containing the highest amount of sugar (glucose AUC 101.7 +/- 14.0 mmol/l.120 min) compared with the non-sweetened cereal (155.5 +/- 18.0 mmol/l.120 min, P < 0.01). There was a significant inverse correlation between the amount of sucrose incorporated and the degree of glycaemia (analysis of covariance coefficient = -1.25, P = 0.00). Similarly, the plasma insulin response was significantly lower after the highest sugar meal (insulin AUC 2267 +/- 346 microU/ml.120 min) compared with the meal without sugar (3505 +/- 365 microU/ml.120 min, P < 0.01).
Conclusions: We found a significant reduction in glycaemic and insulin responses when sugar replaced the rapidly digested starch in a processed breakfast cereal, i.e. the opposite of what is commonly believed. Thus sweetened breakfast cereals may not compromise glycaemic control more so than the unsweetened counterpart.