Those who often eat snacks before bed should be careful because they contain a lot of sugar, which may increase the risk of hormone-driven cancers such as breast cancer. Researchers from the University of California, San Diego School of Medicine found that this may increase the risk of hormone-driven cancers such as breast cancer. Researchers analyzed data from 2,212 women and found that for every three hours of extended nighttime fasting, blood sugar levels were 4 percent lower. A growing number of experts believe that blood sugar provides energy for rapidly dividing cancer cells and that insulin, which is responsible for lowering blood sugar, stimulates cancer cell growth, so keeping blood sugar levels steadily low reduces the risk of hormone-driven cancers such as breast cancer.