Fructose, sucrose, ethanol, metabolised differently to glucose and via pathways which cause increased energy storage as fat, decreased ability to sense fullness and stop eating, decreased ability to release energy from fat and use it, and more unpleasant byproducts.
You eat the wrong things, hence you don't feel full as you should, hence you eat too much, hence a belly. (Maybe).
http://www.youtube.com/watch?v=dBnniua6-oM
Fructose, sucrose, ethanol, metabolised differently to glucose and via pathways which cause increased energy storage as fat, decreased ability to sense fullness and stop eating, decreased ability to release energy from fat and use it, and more unpleasant byproducts.
You eat the wrong things, hence you don't feel full as you should, hence you eat too much, hence a belly. (Maybe).