Every cell in your body, from a brain cell to a toenail cell “eats” sugar. Cells use a simple sugar, called glucose, as the fuel they need to live and work. The entire job of your digestive system is to convert the various foods you eat into glucose to fuel the machine that is you. So it is a normal process for food to be broken into glucose, and for that glucose to enter into your blood so it can be transported to every single cell in your body. Of which there are more than 10 trillion, by the way. In those of us with diabetes however, either dysfunctional insulin or lack of insulin can cause too much sugar to remain in the blood, rather than going into the cells were it is needed. So to answer your question, the sugar in your blood came from the food you ate, and it is staying in your blood instead of going where it belongs because something has gone wrong with the insulin system (diabetes). So even if you never ate one grain of sugar, you could still have sugar in your blood, because a wide variety of foods are broken down into sugar by your body. And good thing too, because without enough sugar to eat, the cells would die and the sugar is removed from the blood by Sugar in the blood is primarily present in the form of glucose. This molecule is taken up via the so called GLUT-transporter, which is mainly present on the skeletal muscle cells (normal muscle cells). Excessive blood glucose, it is taken up by the liver and stored as glycogen - glucose packet together in long chains - and released to the blood when there is need for it.<span> </span>
