Remember how you felt the last time you ate a lot of sugary foods?
You probably got a quick burst of energy, and then it let you down, way down. Maybe you felt "hung over" later with a headache. Maybe it upset your stomach? Or did you get a toothache?
Or are you so used to eating a lot of sugar that you no longer feel the negative side effects?
Think of these things the next time you're about to choose to eat candy, cakes, cookies, ice cream, soda, syrup, etc. Remember what it feels like after the sugar high wears off.