A glycemic load chart is a tool for determining how carbohydrate-containing foods affect blood sugar and blood insulin levels. Using the chart can help health-conscious people choose foods when planning meals. A glycemic load chart lists foods on a scale from one to 100, with lower numbers indicating that a food has a lower effect on blood sugar and insulin.
A score of 20 or higher is considered high, between 11 and 19 is medium, and 10 or lower is considered low. Foods with a lower glycemic load are healthier for people who have heart disease, diabetes, or who want to lose weight, because they enter the bloodstream more slowly and do not spike blood sugar levels.
Scientists have known that differing qualities of carbohydrates have differing effects on the body for quite some time. For years they used the glycemic index to measure how much foods raise blood sugar levels. To calculate the glycemic index of a food, scientists use a standard measurement of 50 grams of carbohydrate to measure its effect on blood sugar. The problem is that foods contain differing amounts of carbohydrate. The glycemic index may exaggerate the impact of foods that only contain a small percentage of carbohydrate, while minimizing the impact of foods lower on the glycemic index, but contain higher percentages of carbohydrate.
Using the glycemic index can be useful but does not give the whole story. Glycemic load may be a better indicator of the impact a food has on blood sugar than glycemic index because it considers actual portion sizes. To calculate glycemic load, the glycemic index of a food is multiplied by 100 and divided by the amount of carbohydrate in a standard portion size.
For example, carrots score 47 on the glycemic index chart but only 2 on the glycemic load chart. This is because the glycemic index does not take into account the low percentage of carbohydrate a carrot contains. It would take 1.5 pounds (700 grams) of carrots to equal the amount of carbohydrate used to measure the glycemic index of carrots. Based on a standard portion size, the glycemic load chart gives a more realistic measurement of carrots’ impact on blood sugar.
Foods that rank lower on the glycemic load chart tend to be vegetables, beans, nuts, and foods that contain more whole grains and more fiber. Refined carbohydrates rank higher on the glycemic load chart. People who wish to lose weight or control heart disease or diabetes should choose less-processed foods for most meals and can use the glycemic load chart to discern which foods will help achieve their health goals.