Glycaemic index and glycaemic load of selected popular foods consumed in Southeast Asia.

The objective of the present study was to determine the glycaemic index (GI) and glycaemic load (GL) values of standard portion sizes of Southeast Asian traditional foods. A total of fifteen popular Southeast Asian foods were evaluated. Of these foods, three were soft drinks, while the other twelve were solid foods commonly consumed in this region. In total, forty-seven healthy participants (eighteen males and twenty-nine females) volunteered to consume either glucose at least twice or one of the fifteen test foods after a 10-12 h overnight fast. Blood glucose concentrations were analysed before consumption of the test food, and 15, 30, 45, 60, 90 and 120 min after food consumption, using capillary blood samples. The GI value of each test food was calculated by expressing the incremental area under the blood glucose response curve (IAUC) value of the test food as a percentage of each participant's average IAUC value, with glucose as the reference food. Among the fifteen foods tested, six belonged to low-GI foods (Ice Green Tea, Beehoon, Pandan Waffle, Curry Puff, Youtiao and Kaya Butter Toast), three belonged to medium-GI foods (Barley Drink, Char Siew Pau and Nasi Lemak), and the other six belonged to high-GI foods (Ice Lemon Tea, Chinese Carrot Cake, Chinese Yam Cake, Chee Cheong Fun, Lo Mai Gai and Pink Rice Cake). The GI and GL values of these traditional foods provide valuable information to consumers, researchers and dietitians on the optimal food choice for glycaemic control. Moreover, our dataset provides GI values of fifteen foods that were not previously tested extensively, and it presents values of foods commonly consumed in Southeast Asia.

The impact of eating methods on eating rate and glycemic response in healthy adults.

Singapore is an island state that is composed of three major ethnic groups, namely Chinese, Malay and Indian. Its inhabitants consume food either using chopsticks (Chinese), fingers (Malay and Indian) or spoon (Chinese, Malay and Indian). Previous work by our group showed that the degree of mastication significantly influenced the glycemic response. The degree of mastication in turn may depend on the eating method as the amount of food taken per mouthful and chewing time differs between eating methods. Eleven healthy volunteers came in on six non-consecutive days to the laboratory and evaluated three methods of eating white rice (spoon, chopsticks and fingers) once and the reference food (glucose solution) three times in a random order. Their glycemic response (GR) was measured for the subsequent 120 min. Mastication parameters were determined using surface electrode electromyography. The GR to white rice eating with chopsticks was significantly lower than spoon. The GI of eating rice with chopsticks was 68 which is significantly lower than eating with spoon (GI=81). However there were no differences between fingers and spoon, and between fingers and chopsticks either in GR 120 min or GI. The inter-individual number of mouthful, number of chews per mouthful, chewing time per mouthful and the total time taken to consume the whole portion of rice were significantly different between spoon and chopsticks groups. Significant correlations between the number of mouthful to take the entire portion of rice and amount of rice per mouthful during mastication and the GR were observed for eating rice with spoon and chopsticks, but not for fingers. The results suggest that individual differences in number of mouthful and amount of rice per mouthful may be two of the causes for inter-individual differences in the GR between spoon and chopsticks. The present study suggests that eating rice with different feeding tools has different chewing times and amount of food taken per mouthful and then alters the GI of the rice.

Effect of chicken, fat and vegetable on glycaemia and insulinaemia to a white rice-based meal in healthy adults.

PURPOSE: White rice is the main staple for the majority in the world. The effects of protein, fat and vegetables on the glycaemic and insulinaemic responses to a white rice-based meal have not been reported. The aim of this study was to determine the effect of co-ingesting a high-protein food (breast chicken), a fat (ground nut oil), a leafy vegetable or all three on the glycaemic and insulinaemic responses of white rice in healthy adults. METHODS: This was a randomized crossover trial conducted at the Clinical Nutrition Research Centre in Singapore. Twelve healthy volunteers were given five test meals (white rice alone, white rice with chicken, white rice with oil, white rice with vegetable and white rice with chicken, oil and vegetable) once and the reference food (glucose solution) three times in a random order at 1-week intervals. Capillary blood samples were then drawn serially for 3 h, and glucose and insulin were analysed. RESULTS: The glycaemic response (GR) to white rice with chicken breast, ground nut oil and vegetable was significantly lower than to white rice alone. The glycaemic index (GI) of pure white rice was 96, whereas combined with chicken breast, ground nut oil and vegetable, it was 50. The addition of oil delayed the peak glucose response and reduced the iAUC, resulting in a GI value of 67. The addition of chicken and vegetable resulted in a GI value of 73 and 82, respectively. The insulinaemic index (II) of the white rice-based meals varied between 54 and 89. Chicken breast in the meal increased the insulinaemic response and decreased the GR. White rice II was lower than the glucose control, which indicated that the former was not as insulinogenic as the latter. White rice with vegetable had the lowest II. CONCLUSIONS: Co-ingesting chicken, oil or vegetable with white rice considerably influences its glycaemic and insulinaemic responses. Co-ingesting white rice with all three components attenuates the GR to a greater degree than when it is eaten with any single one of them, and that this is not at the cost of an increased demand for insulin.