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 over-eating
long after blood glucose returned to normal. Low blood sugar causes
over-eating 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 over-work 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.
