Glycemic Index

In a study that appeared in the Journal of the American Medical Association on May 8, 2002, a great deal of research was reviewed to determine the validity of claims that the glycemic index of a food could determine its effects on the body.

The body regulates the levels of blood glucose to avoid the detrimental effects of a prolonged high, or low, blood sugar by releasing hormones like insulin and other chemicals. High blood glucose causes insulin production, which helps the glucose move out of the blood stream and into fat cells and muscles. Low blood glucose causes the release of other chemicals and hormones, which reduce the effectiveness of insulin and help bring blood glucose back to normal levels.

Meals containing high glycemic foods can cause the blood glucose to rise twice as high, as a meal of low glycemic foods, containing the same number of calories and nutrients. The high glycemic meal causes a much higher insulin output, which would tend to increase the storage of glycogen and fat. Even though nutrient absorption slows after 2-4 hours, elevated levels of insulin remain, causing blood glucose to drop further--often resulting in hypoglycemia—very low blood glucose. Four to six hours after this meal, a second group of hormones is released, in amounts normally found only after many hours of fasting, as the body fights to restore nutrient levels in the blood.

High glycemic meals raise blood glucose so high, extra insulin is produced, quickly sending sugars into the body cells, dramatically lowering blood glucose, causing the body to release hormones to increase hunger and appetite to restore blood glucose. In tests where drugs are given to prevent the uptake of glucose into cells, subjects showed increased appetite and overeating long after blood glucose returned to normal. Low blood sugar causes overeating even though it all began with a very high blood sugar.

Although no long-term studies have been done on humans, rats fed a high glycemic diet show changes that favor fat storage. Human studies have that high glycemic meals are less filling, lead to feelings of hunger sooner or increase meal size as opposed to low glycemic meals.

Studies show:

After a high glycemic breakfast, children continued to consume 53% more calories before supper-time than children eating a low glycemic meal.

Studies show more weight loss on low glycemic-calorie restricted diets than high glycemic diets of the same calories.

Infants born to women on high glycemic food patterns had a higher body fat.

In conclusion, it does seem that high glycemic diets may increase appetite, food intake, fat deposition and overwork the cells that produce insulin. High glycemic foods may therefore increase the risk of obesity, type 2 diabetes and heart disease. In light of the evidence produced so far, it would seem prudent to increase intake of low glycemic foods.

To increase low glycemic foods in your diet increase consumption of fruits, vegetables and legumes. Choose pasta, stone ground breads and old-fashioned oatmeal, over potatoes and instant rice. The less processing a food has, the more fiber it retains and the lower its glycemic rating, too. Rice cakes are high Glycemic. Oranges, apples and cherries are lower than watermelon or bananas. Stated simply high fiber, natural foods are better for your health.