Home Nutrition Want to get in shape: Discover Glycemic Index (GI)

Want to get in shape: Discover Glycemic Index (GI)

Glycemic Index and Glycemic Load
High GI and Low GI effect on body

You might have heard from so many fitness enthusiasts about having low GI diet, but what is this GI (Glycemic Index) and why it is important for health conscious people?

GI is the numerical ranking of carbohydrates on a scale from 0 to 100 according to the extent to which they raise the blood sugar level after being eaten. The rapid rise in level of blood sugar corresponds to higher GI value of food and food with low GI has low or moderate rise in glucose level after being eaten.

The carbohydrate/food after being eaten is broken down and turned into glucose by digestive process which is then absorbed by the blood stream, this absorption initiates the secretion of insulin which helps body to use this glucose as energy. Once the requirement of energy is met, insulin helps our body to store extra glucose in as fat. The food/carbohydrate which breaks down and absorbed quickly during digestion has high GI value and shows high fluctuation in blood sugar level and insulin which results in type1 and type2 diabetes. The food with low GI gets digested and absorbed slowly which keeps the level of blood glucose and insulin moderate and thus benefits the health. Glycemic Index of 70 or above is considered as high, GI of 56-69 is considered as medium and GI of 55 or below is considered as low.

One important point to understand is that the GI value itself is not sufficient for proving whether food is good or bad for health, there is one more numeric value called “Glycemic Load (GL)” which we need to understand. When the carbohydrate is eaten blood glucose rises and falls, but how high it will rise and how long it will remain high depends on the quality and quantity of carbohydrate. GL factors in both the quality and quantity of carbohydrate and is the best way to predict the value of glucose of any food. The formula of Glycemic Load (GL) is:

GL = (GI x the amount of carbohydrate) divided by 100


A standard size Orange has GI of 40 and it contains 11 grams of carbohydrate.so

GL = 40×11/100 = 4.4

GL of 20 or above is considered as high, GL of 10-19 is considered as medium and GL of 10 or below is considered as low. Glycemic Load approach for diet plan is better because it factors in quantity of food for the calculation. Sometimes the GI of food is high but its typical daily serving doesn’t contain much carbohydrate which makes its Glycemic Load value low and thus consuming that food has low Glycemic effect. For instance Pumpkin has high GI value of 75, despite of that its Glycemic Load value for 100g serving is low, so consuming typical serving of pumpkin doesn’t have high Glycemic effect.

It is proven that low GI diet is healthy for the people suffering from type1 and type2 diabetes as it reduces the level of blood glucose and production of insulin. Low GI foods are good option for people who are weight conscious as it controls appetite and make body full for longer. Brown rice has low GI and White rice has high GI. When we consume white rice it digests quickly and gives the feeling of instant energy. In the contrary brown rice takes time to digest and keeps us full for longer as it is more fibrous than white rice and thus keeps production of sugar level and insulin moderate. All the legumes, fruits, nuts, vegetables has low GI values.

The food with low GI cannot always be considered as a healthy food. Like potato chips which have low GI value but has high GL and are very high in fats. It’s not like food containing high fat is worst choice for optimal health but fat shouldn’t be saturated as they increase the risk of heart diseases. Food like biscuits, cakes, fried food, dairy products, all contains saturated fat. It is very important to go for good fat in food i.e. unsaturated fat which is very beneficial for strong and healthy heart, fat loss, good cardiovascular activities and anti-aging.

The Gl and GL are strictly based on the cooking method of food. Baked potato with skin has lower GI of 69 and GL of 19 as compared to baked potato without skin which has GI of 98 and GL of 26. The meals containing protein and fats lower the response of Glycemic as protein and fats doesn’t have carbohydrate so they have GI and GL value of 0. While choosing food (vegetables, fruits, nuts and legumes) it’s not advisable to always go for low GI products, you should also consider other nutrition facts as well. Use your instinct to choose good food with low GI and unsaturated fat which can be a good option to go for an optimal health.

Low to medium GI and GL food is optimal choice for athletics, body builders, pregnant women, kids, old aged persons. In short it benefits everyone as it saves from many heart problems, cardiovascular problems, diabetes, helps in weight loss, increases stamina, boost metabolism and keeps blood sugar level low. While you benefit from eating low GI carbs at each meal, this doesn’t have to be at the exclusion of all others. So enjoy baking your own bread for occasional treats and if you combine high GI bakery products with protein foods and low GI carbs such as fruit or legumes, the overall GL value will be medium.

Useful Links

Glycemic Index of World’s Healthiest Foods
Values of the Glycemic Index (GI) and Glycemic Load (GL) for few common foods
Frequently Asked Questions on Glycemic index (GI) and Glycemic load (GL)