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.
- Chicken protein
- Glycaemic index
- Insulinaemic index
- White rice