###### Abstract  
The present study investigated the effect of apple consumption on postprandial blood glucose and insulin levels in subjects with normal versus impaired glucose tolerance. The study participants were ten healthy subjects with no glucose intolerance (normal subjects) (mean, 24.4 \(\pm\) 4.8 years) and nine subjects with impaired glucose tolerance (mean, 45.2 \(\pm\) 11.1 years, including 2 on insulin therapy). The test meal included white rice (148 g) and a Fuji apple (150 g). The normal subjects were randomly divided into two groups: the apple-first group, wherein the subjects consumed white rice 5 min after consuming the apple, and the rice-first group, wherein the subjects consumed an apple 5 min after consuming the white rice. Blood samples were then taken from both groups for 3 h. In addition, the subjects with impaired glucose tolerance received the same treatment as the normal subjects, with the difference being glucose level monitoring according to the order in which the apples were consumed. In the normal subjects, the Cmax of Ablood glucose and \(\Delta\)insulin levels were 54.0 \(\pm\) 5.0 mg/dL and 61.9 \(\pm\) 7.2 \(\mu\)U/dL versus 46.2 \(\pm\) 5.9 mg/dL and 49.8 \(\pm\) 8.5 \(\mu\)U/dL in the rice-first and apple-first groups, respectively. The incremental area under the curve (iAUC) of insulin tended to decrease in the apple-first group. In the impaired glucose tolerance subjects, the Cmax of \(\Delta\)blood glucose was 75.2 \(\pm\) 7.2 mg/dL in the apple-first group compared to 90.0 \(\pm\) 10.0 mg/dL in the rice-first group, which was a significant difference (_p_ < 0.05). The iAUC of blood glucose was lower in the apple-first group. Eating an apple before a meal may be a simple and effective strategy for managing the glycaemic response in individuals with impaired glucose tolerance. apple; impaired glucose tolerance; intake timing; postprandial blood glucose 2022111803390/1112180390/11/18  
after meals are associated with a higher risk of developing diabetes. Diabetes mellitus can lead to complications such as retinopathy, nephropathy, and neuropathy, the late stages of which can lead to blindness, the need for dialysis therapy, and reduced quality of life [4; 5; 6]. Postprandial hyperglycemia also increases the risk of atherosclerosis as it causes the production of reactive oxygen species and exposes the blood vessels to oxidative stress. The priority in the prevention of diabetes mellitus is to improve overall lifestyle, particularly exercise therapy and dietary intake. To prevent these problems, it is important to take preventive and progressive countermeasures for patients with diabetes by making dietary improvements. The concept of the glycemic index (GI), a measure of the increase in blood glucose that occurs after a meal, has been studied extensively since it was first proposed by [PERSON] et al. [7]. The authors reported that the consumption of low GI foods, which slowly increase blood glucose levels after a meal, is useful for controlling blood glucose and improving blood lipids in diabetic patients [8; 9]. Controlling postprandial hyperglycemia is an important point in the treatment of T2D [10; 11]. T2D mellitus is treated with a combination of diet, exercise, and drug therapy. Drug therapy using insulin secretagogues, biquanides, insulin resistance ameliorators, and alpha-glucosidase inhibitors is especially effective. Of these, alpha-glucosidase inhibitors are taken just before a meal, as evidenced by past studies, and are particularly useful for reducing postprandial hyperglycemia. They modestly decrease glycosylated hemoglobin levels and also reduce the postprandial insulin concentration of blood glucose, as evidenced by data from multiple sample timings after intake [12]. It is already known that taking other macronutrients before carbohydrates ('preloads', e.g., whey protein) and changing the order of intake can affect blood glucose levels [13; 14].