A diet filled with high glycemic-index, GI, foods is an unhealthy diet. This type of diet can lead to a range of metabolic and chronic diseases, including coronary heart disease, peripheral artery disease, Type 2 diabetes, hypertension and stroke. Following a low-GI diet helps keep plasma glucose and insulin at normal levels so that good health and body fat reduction can be achieved. Low glycemic foods have glycemic indices of 55 or lower; whereas, high glycemic foods have values of 70 or higher.
Glycemic Index
Glycemic index is a measure of how rapidly a given food raises plasma glucose. The glycemic index value of glucose at 100 is used as the reference value. Glucose-rich foods, carbohydrates, generally have high glycemic index values; whereas, proteins and vegetables have low values. The rate of glucose absorption from the food in the small intestine is another determinant of the glycemic index value.
Plasma Glucose
High glycemic diets make it difficult to maintain plasma glucose at a normal level of 90 to 100 mg/dL, setting the stage for chronic diseases. Plasma glucose level is rapidly elevated when you consume high glycemic foods. If the amount of high glycemic foods consumed is high, plasma glucose can remain elevated for prolonged periods.This sustained elevation in plasma glucose can lead to a decrease in insulin sensitivity, making it difficult for insulin to manage the body's energy utilization.
Insulin Sensitivity
Sustained elevation of plasma glucose often leads to a decrease in insulin sensitivity and impairment in the body's ability to regulate plasma glucose. When insulin sensitivity declines, insulin-supported uptake of glucose by the muscles and liver become impaired while insulin-facilitated synthesis and storage of fat accelerates. Obesity, Type 2 diabetes, atherosclerosis, ischemic stroke and numerous other metabolic diseases can arise.
Sources of High Glycemic Foods
High glycemic foods are found primarily in refined carbohydrates such as refined flour and foods made from refined flour. These include cakes, donuts, muffins and breads. Refined sugar and beverages containing refined sugar are another source of high glycemic foods.
