GLYCEMIC INDEX

What is the Glycemic Index?

The glycemic index (GI) is a measurement of how much certain foods raise blood sugar levels. Foods are categorised as low, medium, or high glycemic on a scale of 0-100. The lower a food's GI, the less it may affect your blood sugar levels.

This is the three ratings for GI:

Low: 55 or less

Medium: 56–69

High: 70 or above

''Low GI products deliver health benefits that are beneficial to a range of different people.''

-Simon Gilmour | Research Scientist in Nutrition

Factors that affect the GI of a food

• The type of sugar found in it. It's a common misconception that all sugars have a high GI. Sugar has a GI that ranges from 23 for fructose to 105 for maltose. As a result, the GI of a food is affected by the type of sugar it contains.

• The starch's structure. Starch is a carbohydrate made up of two molecules: amylose and amylopectin. Amylose is difficult to digest, whereas amylopectin is simple to break down. Foods that contain more amylose will have a lower GI.

• The degree to which the carb has been refined. Grinding and rolling, for example, disrupt amylose and amylopectin molecules, raising the GI. In general, the higher the GI of a food, the more processed it is.

• Composition of nutrients. Adding protein or fat to a meal can help slow digestion and reduce glycemic response.

• Cooking technique. Preparation and cooking techniques can also have an impact on the GI. In general, the longer a food is cooked, the more quickly its sugars are digested and absorbed, raising the GI.

• Ripeness. Unripe fruit contains complex carbohydrates that degrade into sugars as it ripens. The higher the GI of the fruit, the more ripe it is. An unripe banana, for example, has a GI of 30, whereas an overripe banana has a GI of 48.

There has limitations are describe below

The glycemic index only considers the relative rise in blood sugar after a meal and does not take into account other bodily responses such as the insulin response. The insulin index can be used to calculate the insulin response to a meal.

One of the major disadvantages of the glycemic index is that the glycemic response to a particular food varies not only between individuals but also from day to day and even throughout the day.

The glycemic index of various foods can vary depending on a number of factors. The ripeness of a fruit, for example, can affect its glycemic index, as can the variety of fruit and the method of preparation.

The glycemic index is only based on the glycemic response two hours after a meal, not on subsequent periods. Blood sugar levels in most diabetics can remain elevated for up to four hours after a meal.

EXAMPLE OF FOOD ITEM