Because corn contains low crude fiber and soluble sugar, it is an ideal food for diabetic patients. For example, the sugar content in old corn is 2.3% lower than that of regular rice, while its crude fiber content is almost 9 times that of rice. These factors help diabetic patients lower their postprandial blood sugar levels. However, corn comes in many varieties, and some are not suitable for consumption by diabetic patients. For instance, sweet corn has a soluble sugar content that is 2% to 15% higher than rice, most of which is sucrose, glucose, and fructose, which can easily cause blood sugar levels to rise after consumption.
In addition, waxy corn has a high content of amylopectin, which is easily digested and absorbed, causing blood sugar to rise faster than other grains after consumption. Therefore, it is not recommended to be eaten alone and can be paired with bean flour or foods rich in dietary fiber to slow the rise in blood sugar. Black corn is also mostly waxy, so it is best to eat it with coarse grains like bean flour and oats.