Column #25

The definition of “Glycemic” is “the presence of glucose in the blood.” Some prefer the phrase “blood sugar” instead of “glucose.”

The blood sugar level changes throughout the day. It can fluctuate rapidly within minutes depending on the food or beverage one consumes. The measured response to food consumed also varies from individual to individual. Compounding this confusion is that there are two measurements: Glycemic Index (GI) and Glycemic Load (GL).

GI was created in 1981. It measures how quickly a food containing 50 grams of carbohydrate raises blood-glucose levels. An index value of 100 is a standard response for an equivalent amount of pure glucose. GI represents the increase in blood sugar level and may or may not represent how fast it increases.

Since many foods have a low carbohydrate content, the GL measure was created. One GL unit approximates the consumption of one gram of glucose. GL is calculated by multiplying the grams of available carbohydrate in the food times its GI divided by 100. Watermelon has a high GI of 72, but with only 5 grams of carbohydrate it has a low GL of 3.6. The calculation is 72 x 5 / 100.

Consequently, GI and GL have different scales. GIs range from 0 to slightly higher than 100. A GI below 55 is considered low, 63 is midway, and 70+ is high. The GL scale ranges from 0 to about 90. A GL measure of 10 or less is considered low, 11-19 is considered medium, and 20+ is considered high.

When a body consumes food, it decides whether to store it in adipose tissue fat cells or burn it as energy. To ensure survival, humans are hardwired to store food in fat cells first. Therefore if the food has a high GI and GL it will be quickly stored. If the GI and GL are low the food will more likely be used as energy.

High glycemic foods spike blood sugar levels and energy. The body reacts to the rapid increase in blood sugar by releasing insulin to lower it. The resulting sharp drop in blood sugar reduces the energy supply and triggers mild to intense hunger.

Studies show that low-GI diets over many years significantly reduce the risk for developing type 2 diabetes, coronary heart disease, cancer, obesity, age-related macular degeneration, gallbladder disease, and fungal issues. Repetitive glycemic spikes following meals tend to promote disease. One wonders then, why are high glycemic foods fed to children?

Glycemic measurements play an important role in the diet, but they are not the end all. Avoiding foods that spike blood sugar is just one of three key factors in food selection. The others involve nutrient diversity and density and the balance of essential nutrients which include Omega-6 and Omega-3 fatty acids.

Meat, poultry, fish, avocados, salad vegetables, cheese, or eggs contain little or no carbohydrate therefore they do not have GI numbers. Even in large amounts, these foods when eaten alone are not likely to induce a significant rise in blood glucose.

The Real Diet of Man emphasizes low glycemic, properly balanced, nutrient dense foods such as grass-fed and omega-3 meats, wild-caught seafood, green leafy vegetables, and a limited amount of tart fruit. It’s the roadmap to better health.

To your health.

Ted Slanker

Ted Slanker has been reporting on the fundamentals of nutritional research in publications, television and radio appearances, and at conferences since 1999. He condenses complex studies into the basics required for health and well-being. His eBook, The Real Diet of Man, is available online.

For additional reading:

International Table of Glycemic Index and Glycemic Load Values: 2002

Glycemic Index and Glycemic Load

Glycemic Index Defined