Dr. Robert Fogel at the University of Chicago and other scientists around the world have/has concluded that a significant change in people’s physical size has taken place.

for this, you need to remember something significant in your own life, for example, if you were bullied when you were younger, you can mention your memories on this and touch on how such treatment can harm other kids your age either physically or mentally. (racism, car crashes, a parent in the hospital are all very good subjects, think hard on it! )

hope i ! : )