A paragraph in an essay and NOT an example of insertion.
Dear brother,
The amount of junk food is bad for your health. You are not getting the necrssary vitamins and minerals to support your body. Instead, you are getting a lot of calories and storing fat in your body.
From your sibling
One thing interesting about the setting in the short story "Through the Tunnel" is that author Doris Lessing carefully uses word choices to show the striking contrast between the beach and the enticing rocky bay, and the contrast helps set the mood of the story and develop the major theme.