Glycemic index, glycemic load and insulinemic index of Chinese starchy foods

Abstract

Aim: To determine the glycemic index (GI), glycemic load (GL) and insulinemic index (II) of five starchy foods that are commonly used in Chinese diets.

Methods: Ten healthy subjects aged between 20-30 years were recruited. Each subject was asked to consume 50 g of available carbohydrate portions of test foods and reference food. Finger capillary blood samples were collected at the start of eating and 15, 30, 45, 60, 90 and 120 min after consumption. The GI and II of foods were calculated from the ratio of incremental area under the glucose/insulin response curves of test and reference foods. The GL for each test food was determined from its GI value and carbohydrate content.

Results: The results showed that brown rice elicited the highest postprandial glucose and insulin responses, followed by taro, adlay, yam and mung bean noodles, which produced the lowest. Among the five starchy foods, brown rice evoked the highest GI and GL at 82 ± 0.2 and 18 ± 0.2, followed by taro (69 ± 0.4, 12 ± 0.2), adlay (55 ± 0.4, 10 ± 0.2), yam (52 ± 0.3, 9 ± 0.0) and mung bean noodles (28 ± 0.5, 7 ± 0.2), respectively. The II values of the test foods corresponded with GI values. Similarly, brown rice gave the highest II at 81 ± 0.1, followed by taro (73 ± 0.3), adlay (67 ± 0.3), yam (64 ± 0.5) and mung bean noodles (38 ± 0.3). All five starchy foods had lower GI, GL and II than reference bread (P < 0.05).

Conclusion: The GI, GL and II values of starchy foods provide important information for the public to manage their diet and could be useful for the prevention of lifestyle-related diseases such as diabetes mellitus.

Figure 1

Mean glucose concentrations elicited by five different starchy foods in healthy subjects. Data are expressed as the change in plasma glucose concentration from the fasting baseline concentration.

Figure 2

Mean insulin concentrations elicited by five different starchy foods in healthy subjects. Data are expressed as the change in plasma insulin concentration from the fasting baseline concentration.

Figure 3

Glycemic index, glycemic load and insulinemic index values of the starchy foods. The mean glycemic index (GI), glycemic load (GL) and insulinemic index (II) for the reference food (white bread) and the five tested starchy foods. For the GI values, columns with different superscripts (a, b, c, d, e, f) are significantly (P < 0.05) different. Columns representing the GL values with different superscripts (v, w, x, y, z) are significantly different (P < 0.05). Columns representing the II values with different superscripts (A, B, C, D, E, F) are significantly different (P < 0.05).