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 hypoglycemiavery
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.
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