Some foods can make you hungry fast!|
By Michael Woods, Toledo Blade science editor|
MONDAY, Apr. 2 (Toledo Blade) — Your meals are chips right off the old block - blocks of the Food Pyramid, that monument to good nutrition promoted by government and private health agencies. They are low in fat and high in carbohydrates.
A few hours after each meal, however, you’re starving and eat more. Despite eating by the pyramid, you’re gaining weight.
Some nutritionists think the Food Pyramid needs repairs. They fear its emphasis on substituting high-carbohydrate foods for fats may actually be contributing to the epidemic of obesity sweeping the nation.
The pyramid advises people to build their whole diet on a foundation of bread, grains, and other high-carbohydrate food. Lots of carbos, it says, are good. Fats are bad. It illustrates that idea by placing fats, oils, and meats near the narrow peak. Carbohydrates make up the broad base. Fruits and vegetables are in-between.
Experts say it ignores differences between fats, some of which, such as olive oil, have good effects on blood cholesterol.
More important, the pryamid ignores the "glycemic factor" in carbos and other foods. The glycemic factor - the "hunger factor" - is a number showing how blood sugar increases after eating a specific carbohydrate.
Foods such as white bread, baked potatoes, white rice, bananas, and most cold breakfast cereals have a high glycemic index. They cause a fast rise in blood sugar. The body reacts by producing insulin, which quickly drops blood sugar levels, usually making a person feel ravenous.
Satisfy the hunger with more high-glycemic food, and the hunger-eat-hunger cycle repeats. Those extra calories may get stored in the body as fat.
Carbohydrates consist of glucose, or sugar, units linked together into long chains. Digestion breaks the chains, and releases glucose into the blood.
Scientists once assumed that all carbohydrates released sugar units at the same rate. Now they know that carbohydrates break down at different rates. White bread and potatoes release glucose quickly. Baked potatoes actually have a higher glycemic index than pure sugar. Beans, lentils, whole grains, and protein-enriched pasta release glucose more slowly.
Nutritionists incorporated the new knowledge into recommendations for people with diabetes, who must keep blood sugar levels steady.
Now they’re focusing on the glycemic index’s importance for everyone else. Some agree with Simin Liu, a Harvard University medical school nutritionist who has termed the glycemic index "the most fascinating and promising area in nutritional research today."
Studies suggest that people who regularly eat foods with a high glycemic index may increase their risk of developing insulin resistance. That’s a condition in which body tissues become less sensitive to insulin. The body compensates by producing abnormally large amounts of insulin.
People with the condition may face an increased risk of diabetes, heart disease, and other problems.
Scientists with the U.S. Department of Agriculture, Tufts University’s Human Nutrition Research Center, and other institutions have found that low-gylcemic-index foods reduce hunger and can help in reducing weight. To do so, choose carbohydrates with a lower glycemic index. That means high-fiber foods, whole grains, and other less-processed foods. It also means being choosy about carbos. Protein-enriched pasta, for instance, has a lower index than potatoes.
There are excellent books on the topic (such as Dr. Thomas Wolever’s Glucose Revolution guides), and an Internet search for "glycemic factor" will produce lists of high-glycemic and low-glycemic foods, and more.
Maintaining a normal body weight takes more than eating by the pyramid or any other one-size-fits-all guide. Look at your own eating patterns, and try to discover what makes you so hungry. Maybe it’s the very food you eat.