The basic premise of the low glycemic diet is simple: eating certain foods can keep your blood sugar levels in check, which can help you lose or maintain weight and prevent certain diseases.
There are two common terms you often hear associated with the low glycemic diet: glycemic index and glycemic load.
Glycemic index is a measure of how fast foods break down as sugars in your blood. The glycemic index ranges from 0 to 100, with 100 representing the highest amount of glucose (sugar) in a particular food. Foods that your body digest quickly get a high score and foods that take longer to digest get a lower score.
Glycemic load is a ranking system that takes into account both the amount of carbohydrate in the food and the impact it has on your blood sugar levels. A food’s glycemic load is determined by multiplying its glycemic index by the amount of carbohydrate it contains and dividing by 100.
Glycemic Load = (Glycemic Index x Grams Carbohydrates) / 100
Glycemic load is a more accurate indicator of a food’s impact on your overall health because it takes into account the amount of carbs you’re consuming.
Foods with a glycemic load under 10 have minimal impacts on your blood sugar levels. Foods between 10 and 20 have a moderate impact on blood sugar. And foods with a glycemic load over 20 tend to cause the most dramatic spikes in your blood sugar levels, which can put you at a higher risk of obesity and chronic diseases.
Most high-carbohydrate, starchy foods like potatoes, breads and baked goods tend to have a high glycemic index and glycemic load while most vegetables and foods like oatmeal and beans are lower.
This video from Dr. Andrew Weil does a good job summing up glycemic load vs. glycemic index in two minutes:
So now that you know the difference between glycemic index and glycemic load, let’s see what the research says about low glycemic diets.
Low Glycemic Diet Research
The low glycemic diet is backed by plenty of clinical data and has demonstrated benefits for the following:
- Weight loss
- Cardiovascular disease
Researchers at the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital found that a low glycemic diet resulted in improved cholesterol levels and more weight loss compared to low fat diets and low carb diets.
Another study found that people with diabetes who followed a low GI diet experienced similar benefits to those taking medication. The study authors said “This trial suggests that a low-GI diet is a viable alternative to the ADA (American Diabetes Association) diet.”
Glycemic Index and Glycemic Load in 20 Common Foods
The Final Word on Low Glycemic Diets
As with all diets, some folks take the glycemic index to the extreme, and this can be counterproductive. For example, certain vegetables such as carrots have a high glycemic index because they contain naturally-occurring sugars.
But carrots also have a low glycemic load. And as you learned about 30 seconds ago, this means they don’t have much of a negative impact on your blood sugar levels.
The message here is simple: don’t shun fruits and vegetables because they’re high on the glycemic index.
David Katz, M.D., a nutritionist and the founding director of the Prevention Research Center at Yale University, said:
“Perhaps the single most important observation regarding low-glycemic eating is that it, too, tends to occur as a by-product of favoring minimally processed, direct-from-nature foods and avoiding refined starch and added sugars”.
In other words, if you’re going to follow a low glycemic diet—or any other diet for that matter—you still need to focus on eating mostly real foods that come directly from nature.
- Harvard School of Public Health: Carbohydrates and Blood Sugar
- Mayo Clinic: Nutrition and Healthy Eating
- National Institutes of Health: Non-celiac Gluten Sensitivity
- Wall Street Journal: Not All Calories Equal, Study Shows
- National Institutes of Health: A randomized clinical trial comparing low-glycemic index versus ADA dietary education among individuals with type 2 diabetes
- National Institutes of Health: Effects of a low glycemic load or a low-fat dietary intervention on body weight in obese Hispanic American children and adolescents: a randomized controlled trial
- Harvard School of Public Health: Carbohydrates and the Glycemic Load
- The American Journal of Clinical Nutrition: International table of glycemic index and glycemic load values: 2002
- Annual Review of Public Health: Can We Say What Diet Is Best for Health?
- International Table Of Glycemic Index And Glycemic Load Values
- Glycemic Index And Glycemic Load For 100+ Foods