Hilary Brueck/Insider
The blue shaded area of this graph is the place you want your blood sugar reading to be.
A blood sugar reading below 70mg/dL signals low blood sugar, which can make you faint, weak, shaky, and hungry.
"I wish every citizen in the world could put one of those on," Dr. Mark Cucuzella, a Professor at West Virginia University School of Medicine and healthy eating advocate (who was not involved with this study), said.
"Just to see what is going on."