This is from Dr. Rood's blood sugar experiment. He ate candy and drank soda to force his blood sugar to spike. After about 15 minutes the blood sugar did spike but it quickly tried to work it's way back to equilibrium. over the course of 45 minutes the blood sugar went back to normal however it went below the starting point before getting back to the starting point. This was regulated by negative feedback to keep the body in homeostasis.