This set of guidelines did change the way consumers eat by reducing fat in their diets. The reduction of fat made processed foods less palatable, so the sugar was increased to counteract that affect.
Refined sugars put more strain on the liver, forcing the liver to produce more fat. The liver is the only organ that can process fructose within the body. When a person ingests more fructose than the liver can handle, it produces fat. As the liver gets loaded down with fat, it does not respond to insulin levels, which regulate the metabolism of carbohydrates and fats. The body cannot correctly use energy resources when the liver does not function at full capacity.
When the liver gets packed with fat the body reacts by developing hypertension, stroke, heart attack, obesity and more. As more scientists study the fat/carbohydrate connection, it is being found that sugar is the culprit, not the breads or pastas, which by themselves are low fat and low calorie. Perhaps these current studies will push a new set of guidelines showing that one should decrease the sugar intake, increase healthy fat intake and rethink carbohydrates in the diet.