How can consuming simple sugars affect my eating habits?

Easily digestible foods containing high levels of simple sugars cause a rapid spike in circulating blood sugar. This signals the pancreas to release insulin in order to absorb the glucose. This works well unless the pancreas overshoots insulin secretion, which it commonly does, providing too much transportation of the glucose out of the blood. This causes the blood glucose to fall rapidly and leaves you feeling tired, cranky, shaky, and sometimes lightheaded. This precipitous drop spurs a carb crave three to four hours after a high-carb meal and sends you straight to the refrigerator for more carbs that are high on the Glycemic Index (a measure of the effect of carbohydrates on blood glucose levels and insulin production). Usually, high-index foods also contain a lot of fat and calories, which can set you up for a cycle of overindulging.