Healthy food is one of the most important parts of controlling blood sugar, but many people struggle to afford nutritious meals. Type 2 diabetes develops when the body cannot use insulin properly, causing blood sugar levels to remain too high. Over time, high blood sugar can damage the heart, kidneys, eyes and nerves. Doctors often measure long-term blood sugar using a test called hemoglobin A1c, or HbA1c, which reflects average blood sugar over the previous two to three months. At the end of the study, blood sugar control improved more in the grocery groups than in the usual-care group.