Sugar is a general term used to describe a class of molecules called carbohydrates and it's found in a wide variety of food and drinks.
http://www.businessinsider.sg/effects-of-eating-too-much-sugar-2014-3/
https://www.youtube.com/watch?v=lEXBxijQREo
http://www.npr.org/sections/thesalt/2016/09/14/493957290/not-just-sugar-food-industry-s-influence-on-health-research