Dietary references sometimes talk about certain foods and their glycemic index and glycemic load, ratings used for measuring the effects the food has on blood sugar levels. The terms glycemic index and glycemic load, though they measure the same thing, cannot be used interchangeably as they are calculated very differently. Both measurements can rate a food and determine its effects on stimulating blood sugar, but the ratings, using a numbering system, are different from each other. The carbohydrate content mainly determines the ratings on the glycemic index and glycemic load, as carbohydrates are the main macronutrients present in food that stimulate blood sugar.
Nutritional research into carbohydrates, a macronutrient found in grains, vegetation and dairy, has shown that they can stimulate blood glucose or blood sugar. This sugar is essential for energy, as the hormone insulin helps carry it into the cells of the body which thrive on blood glucose as its main energy source. People with diabetes have trouble using insulin efficiently, resulting in high levels of glucose circulating in the body and never finding its way into the cells. It is often suggested that these people study the glycemic index and glycemic load of a food to find foods that will not stimulate blood sugar quickly or to high amounts.
Foods that rate low on the glycemic index and have a low glycemic load do not spike blood sugar, resulting in stable blood sugar control that is often sought by people with blood sugar issues. The glycemic index and glycemic load numbers rate foods with a number system, and a low number correlates with a lower and stable stimulation of blood sugar. High glycemic foods suggest that the particular item has many simple carbohydrates, like sugar or refined grains, which have a dramatic impact on blood sugar and insulin. These foods are often avoided or severely limited in a low-glycemic diet.
Both forms of measurement rate the carbohydrates of a food, yet their rating system and calculations are rather different. The glycemic index rates a food on a scale from 0 to 100, with 0 to 50 being low on the glycemic index and 51 to 100 being high. Glycemic load uses this information by multiplying the glycemic index of a food by the total grams of carbohydrates in the serving, and dividing by 100. Although the glycemic index and load are different numbers, with the glycemic load often being a lower number, they both mean the same thing.