This paragraph sums it up quite nicely.
"Increases in insulin are most highly stimulated by the consumption of starches and sugars, especially the consumption of refined starches and sugars.
Eating carbohydrates increases insulin which in turn encourages storage of energy as fat rather than making the food energy available to the body to burn. The more highly refined the carbohydrate, the more its consumption stimulates insulin levels. By causing fat storage instead of making energy available for immediate use of the body, refined carbohydrates result in hunger."
http://ruth-wilson-zamierowski.suite...re-fat-a140987