How does blood sugar work? How is sugar transferred into the blood? Sugar in the blood or also called glucose comes directly from what we eat. The digestive system breaks down that food into glucose and absorbs it into the blood. That's why eating foods high in carbohydrates provide most of the glucose in your diet. A simple first step towards controlling your blood pressure is analyzing the starches in your diet.  A new study from Kings College in London, UK indicated that coarser starches made up of larger pieces not only digest more slowly than fine starches, but may also result in fewer blood sugar spikes. What does this mean for you and me? It shows that the shape of a starch determines how it is processed in the body.