A higher glycemic index means that food raises the blood sugar more than a food with a lower glycemic index. Food with a higher glycemic index will also raise the insulin level more than foods with a lower glycemic index in an effort to lower the blood sugar level. Foods with a high glycemic index include starchy foods such as white rice, refined grain prodcuts and potatoes. When these foods are eaten, they are digested into sugar molecules rapidly and the sugar molecules are absorbed rapidly into the blood, resulting in high sugar and insulin levels. However, exceptions to this rule exist.
Some complex carbohydrates have a higher glycemic index than some of the simple carbohydrates.
Eating foods with a high glycemic index may have a number of deleterious effects. Possibly due to the high glycemic index of some of the carbohydrates eaten in these diets, these ultra low fat diets are paradoxically associated with high triglyceride and low HDL cholesterol levels as well as other metabolic abnormalities. These facts have led to many experts recommending that fat intake not be cut so drastically. Such a diet is also much easier for the average person to stick with in the long term than the ultra low fat diet is. Advocates of the ultra low fat diet counter that, despite the above facts, their patients have a very low incidence of heart disease.