Vedanta Delhi Half Marathon

Make the Right Carb Choices! Glycemic Index Versus Glycemic Load


Carbohydrates act as a fuel to keep you going. However, various food sources provide different quantity and quality of carbs. It is important to understand the 2 technical terms that govern their nature: glycemic index (GI) and glycemic load (GL).1,2

Glycemic index (GI)

GI is a way to categorise foods based on how their consumption will affect your blood glucose levels. In simpler words, it’s a ranking system from 1 to 100, which determines how slowly or how quickly your blood glucose levels increase when you consume them.1,2

A high-GI food has a GI of 70 or more
A medium-GI food has a GI between 56 and 69
A low-GI food has a GI of 55 or less

A higher value suggests easy and rapid absorption, thereby increasing the blood glucose levels quicker, whereas a lower GI index provides a slower and steady supply of glucose.1,2

Although the GI just gives us a number, it actually doesn’t give any insights regarding the number of serves. For example, candies have a relatively high GI; however, consuming a single piece of it causes only a small rise in the blood glucose levels. This is because blood glucose response is not only determined by what you eat, but also how much you eat! This confusion demands a more apt system such as Glycemic Load (GL).1,2

Glycemic load (GL)

GL a way to measure the blood sugar raising power per serving/portion of the food consumed.1,2

GL gives a more accurate picture of a food’s real-life impact on the blood glucose level. For example, watermelon has a high GI of about 72; however, a single serving of watermelon has only 5.5 g of carbohydrate determining a GL value of just 4.1-3

The glycemic confrontations!

A few food choices and their respective GI and GL values have been listed below. Read the food labels before buying to know more.3,4

Formula to Calculate GL of Various Foods
GL = GI/100 × g of carbs in a given amount of food1,2A GL of 10 or below is considered low

A GL of 20 or above is considered high

Example: Brown rice3,4

GL = 50 × 32/100

Hence, GL of brown rice = 16

Follow these simple tips

Understanding GI and GL will help you consume the right type and amount of carbohydrates suitable for your activity level or the time of your meal. Here are a few tips you can follow 5,6:

  • Pre-run/workout: Before you get into the field, it’s important that you consume low-GI foods. This helps provide a steady supply of glucose, thus keeping you on your toes! A 30- to 60-minute gap should be good enough.
  • During workout: High-GI and high-GL foods are the best when you are at it! Although it’s not possible to eat while you are working out or running, fluid options can always be helpful to provide a ready burst of glucose.
  • Recovery time: Again, during this period, your muscles need a ready replenishment of glucose. Kick back with those high-GI and high-GL foods.


  1. Augustin L, Kendall C, Jenkins D et al. Glycemic index, glycemic load and glycemic response: An International Scientific Consensus Summit from the International Carbohydrate Quality Consortium (ICQC). Nutr Metab Cardiovas Dis. 2015;25(9):795-815.
  2. Barclay AW, Brand-Miller JC, Wolever TMS. Glycemic index, glycemic load, and glycemic response are not the same. Diabetes Care. 2005 Jul;28(7):1839-40.
  3. Oregon state university. Glycemic index and glycemic load for 100+ food. Oregon, USA: Oregon state university extension; 2016.
  4. Atkinson FS, Foster-Powell K, Brand-Miller JC. International Tables of Glycaemic Index and Glycaemic Load Values: 2008. Diabetes Care. 2008;31(12):2281-83.
  5. Beavers KM, Leutholtz B. Glycemic load food guide pyramid for athletic performance. Strength Cond J. 2008 June;30(3):10-13.
  6. Wein D. Glycemic index for athletes. NSCA’s Performance Training J. 6(3):14-15.