Glycemic Index and why it is important to understand

The glycemic index (GI) measures how a carbohydrate containing food raises the blood sugar (glucose) level. A food’s GI is ranked based on how it compares to a reference food — usually glucose. A food with a high GI raises the blood sugar level quickly and higher than a food with a medium or low GI. The high GI foods hit your blood system like a tidal wave, whereas a low GI food is more like a trickle of sugar.

Your pancreas has a much more difficult time dealing with the tidal wave of sugar than with the trickle. High GI foods give you a rush of energy and then later leave you feeling tired and drained whereas low GI foods give you sustained energy. The American Diabetes Association suggests that we should always plan a meal using foods that have medium and low GI foods and if you do take a high GI food, combine it with the lower GI foods to lessen the effect.

Some examples of carbohydrate containing foods that have a low GI are dried beans, kidney beans, non- starchy veggies, and some starchy veggies like sweet potatoes.

Whole grain breads and whole grain cereals also are considered medium or low GI foods, and all meats and fats are low glycemic because they don’t contain carbohydrate.

So this brings us to the notion that just because a food is low GI does not necessarily mean that it is low calorie. Ice cream, for example, is low GI but very fatty and therefore, high calorie. The fat modifies the speed that the sugar goes into the blood and slows it down because fat takes a longer time to digest.

Glucose is considered as a GI of 100.

Here are some low GI foods with a ranking of 55 or less: stone ground whole wheat or pumpernickel bread, rolled or steel cut oatmeal, oat bran, muesli, sweet potato, yam, corn, lima beans, butter beans, peas, legumes and lentils, non-starchy veggies and most fruits (not dried ).

Foods with a medium GI in the 56 to 69 range include whole wheat, rye and pita bread, quick oats, brown rice, wild or basmati rice and couscous.

High GI foods are those with a rating of 70 or more. Some of these foods are white bread, bagels, short grain white rice, rice pasta, macaroni, pumpkin, potato, popcorn, rice cakes, saltine crackers, melons and pineapple.

The way you prepare your food also contributes to the glycemic index. The amount of fat and fiber in a food modifies the GI. Usually more fat and more fiber tend to lower the GI of any given food.

If a food is very ripe it will likely have a higher GI (because more of the starch is converted to sugar in the ripening process). Juice has a higher GI than a whole fruit because there is less fiber in juice as compared with eating a whole fruit. Overcooked pasta and veggies have a higher GI than firmer, less-cooked options.

Always it is important to balance the protein and the carbohydrates consumed so that energy levels and a full complement of nutrients are taken at each meal. Choosing lower glycemic index foods has also been shown to keep body weight lower and keep it lower over the long term.

The sugar in higher GI foods converts easily into fat in the body, whereas lower GI foods are more readily used for energy rather than stored as fat.

Informing yourself of the GI ratings of many of the foods you consume can help you maintain your weight, your energy levels and help you avoid late onset diabetes.

I hope you decide to look up the value of many of the carbohydrate foods that you like and see where they lie on the scale. Another quick tip is to look at the label on packaged food.

If sugar or glucose is one of the first things listed in the ingredients then you know you have a sugar-laden food and is best combined with other foods to lower the GI or not consumed at all.


Dr. Jane Riley, EdD., is a certified personal fitness trainer, nutritional adviser and behavior change specialist. She can be reached at (808) 212-8119 cell/text., and


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