The Real Value of Understanding Glycemic Load

The new book, Always Hungry?, by David Ludwig, MD, PhD, now a number one New York Times best seller, brings scientific-backed research into the ever-changing landscape of diets and health. Having just read the book, I feel like it’s something that everyone should read at some point to help get a handle on this evolving field where we are constantly inundated with low carb/paleo/high protein/low-fat diets and in turn, have a hard time sifting through it all. Dr. Ludwig is an endocrinologist and researcher from Boston who gets it and explains things from the inside out in regard to how your body processes the food you consume.

It seems like I’m always talking to someone about monitoring their added sugar intake during the day. To really get the picture you need to understand the importance of what the glycemic index and especially the glycemic load are all about. The glycemic index is a measure of the effects of carbohydrates in food on blood sugar levels. The glycemic load on the other hand is really what you should consider because it is based on the specific quantity of carbohydrate content that you consume. According to Dr. Ludwig, glycemic index should be thought of as how foods rank in a laboratory setting, whereas glycemic load applies more “directly to a real-life setting.” Consuming foods that have a high glycemic index and load results in higher and more rapid increases in blood sugar (glucose) levels than when you consume low-glycemic foods. Here is a list of foods to give you an idea of what I’m talking about.

Glycemic Load = Glycemic Index (%) x grams of Carbohydrate per serving  

Consuming carbohydrates that have a low glycemic index and load in addition to calculating carbohydrate intake would produce the most stable blood sugar levels. This is important for you to know because when the opposite occurs and the glycemic load is high following a meal or snack your blood sugar levels spike and insulin, which is a hormone, is released from the pancreas.

“But insulin’s actions extend well beyond blood sugar control, to how all calories flow throughout the body.” Ludwig calls insulin the ultimate “fat cell fertilizer” and high rates of insulin in the body eventually cause weight gain.

If this is repeated often during a day and over long periods of time, you increase your chances of gaining body fat and increase your risk of diabetes and other forms of cancer. A review of six randomized controlled trials determined that overweight or obese individuals who followed a low-glycemic index/load diet experienced greater weight loss than individuals on a comparison diet that was a high-glycemic index diet or an energy-restricted, low-fat diet (1). A second major analysis, also found in Ludwig’s book, found that people with high-GI diets had a a 20 percent increased risk for getting diabetes compared to those with low-GI diets (2).

The glycemic load is one factor you should consider as part of your diet in addition to fiber content and percentage of carbs/fat/protein that make up your diet.

The first step in change is becoming aware of the situation and the more you read food labels and watch your glycemic load – the healthier you will become!


Thomas DE, Elliott EJ, Baur L. Low glycaemic index or low glycaemic load diets for overweight and obesity. Cochrane Database Syst Rev. 2007; (3):CD005105.

Bhupathiraju SN, et al., Glycemic index, glycemic load, and risk of type 2 diabetes: results from 3 largeUS cohorts and an updated meta-analysis. AJCN 2014, 100(1):218-232.


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