Sunday, August 30, 2009

Glycemic Index: Myths and Facts

Myth:

The greatest method to calculate the carbohydrate in a food is by using Glycemic Index.

Truth:

Glycemic index is a scale which informs about the rate of release of glucose from a carbohydrate in the blood stream. It does not calculate the amount of carbohydrate in a food. If a food is consumed in a greater amount, it would result in a higher Glycemic reaction. This happens as there is a higher Glycemic load. This can be explained as that if a person eats two different foods with comparable GI values, the blood glucose released would be greater for the food which is eaten in larger quantity.

Myth:

GI diet proposers suggest that a person, who wishes to loose weight, should avoid foods which are white such as pasta and potatoes because of their high GI values.

Truth:

The white color of food is not the criteria for deciding the GI value, instead it is the method used for cooking the food that is more important. It also depends on whether the food has been processed to a large extent and the foods eaten along. For example, a boiled potato has a lower GI value than a micro-waved potato. Pasta is also a low GI food, but becomes rich by the method of cooking. Most of the foods are cooked in conjunction with other foods which tend to lower the GI values.

Myth:

Healthy foods and unhealthy foods can be divided on the basis of Glycemic Index.

Truth:

GI alone does not decide the healthiness of the food. For example, skim milk has a GI value of 32, while whole milk has a GI of 27. A lower value of GI does not imply that the food will be a healthy food.

Myth:
Simple sugars have high GI values

Truth:

Fruits are rich in simple sugar called fructose. Fructose is digested slowly by the body since it is digested by the liver only. This causes a slow release of glucose in blood stream. Therefore, it is not essential for a food to be made up of complex sugars to be low in GI value.

Myth:

Low insulin levels can be maintained with low GI foods. Hence, any amount of low GI foods can be eaten.

Truth:

It is not necessary that a diet of low GI means that the food can be had in any amount. This is because the insulin level in blood stream depends upon the Glycemic load, which is primarily a combination of GI and carbohydrate eaten. This means that if the carbohydrate eaten is more, it will result in higher glucose levels in blood stream implying a higher value of GI.

Sunday, August 2, 2009

Understanding The Glycemic Index

You might have read about the GI in nutrition magazines, newspapers and even on food labels and might have wondered what the hype is about. However, this is no new weight loss pill or device, it is simply used to monitor and maintain weight. Initially only athletes and diabetics used it, however now just about anybody who cares about weight uses it.

This article presents the facts about the Glycemic Index (GI) so that you can decide for yourselves what the truth about it is.

What is it?

Glycemic Index measures the effect a food has on your blood sugar levels. If a food causes a rapid glucose release into your blood stream, it will have a high GI and vice versa.

Dr. David Jenkins and his team at the St Michael’s Hospital in Toronto developed this so that diabetics could monitor their sugar levels. However, two books The Zone, by Barry Seas and Sugar Busters!, by HI. Leighton Steward et. al. used it as a weight loss tool.

Does it work?

No two dieticians agree on this one. Some claim that a rapid sustained weight loss is possible by taking foods with a low GI. On the other hand, others warn that such foods leave out the vitamins and minerals and are no help in weight loss.

How accurate it is?

The GI of any food varies depending on its country of origin. For example, Canadian carrots had a GI of 92 whereas same amount of Romanian carrots had a GI of 16.

In addition to this, the American Diabetes Association (ADA), says that GI varies if the food is combined with other foods. While jam may have a high GI, if combined with whole wheat bread, the combination has a low GI.

Fat slows down the digestion and therefore, high-fat products have a low GI. Therefore, you would be taking a major risk if you rely only on GI.

Confusion around the GI

There is a lot of lack of data to conclude whether or not this is an effective tool for weight loss or management. It sure is very effective for diabetics and athletes, who have to regulate their blood sugar at all times.

However, for the regular person trying to lose weight or maintain lost weight, the picture is still foggy. The best thing to do is have a balanced diet comprising of 50-60% carbohydrates, 20-30% fat and 10-20% protein.