Monitoring After-Meal Blood Sugar

One of the most important goals in helping people manage blood sugar, lose weight, and control appetite is preventing excessive after-meal elevations in blood sugar levels. The diet strategy involves avoiding foods that cause a rapid rise in blood sugar levels by eating a low glycemic diet. 

Numbers to Know

The glycemic index (GI) is a numerical scale used to indicate how fast and how high a particular food raises blood sugar levels compared to white bread or glucose. It is quite useful in judging the quality of carbohydrate sources, but it doesn’t tell you how much carbohydrate is in a typical serving of a particular food. The glycemic load (GL) takes the GI into account, but it gives a more complete picture of the effect that a food has on blood sugar levels based on how much carbohydrate you actually eat in a serving.

Refined carbohydrate sources (white sugar and white flour products) tend to have a very high GL while foods that are mostly water (e.g., apples), fibre (e.g., carrots) or air (e.g., popcorn) will not cause a steep rise in your blood sugar even if their GI is high–as long as the portion sizes are moderate. A list of the GI, fibre content, and GL of common foods are found in the Appendix of How to Prevent and Treat Diabetes with Natural Medicine by Michael T. Murray and Michael R. Lyon, (Riverhead, 2003).

Fibre Foils Rising Blood Sugar

Fibre supplements have been shown to enhance blood sugar control, decrease insulin levels, and reduce the number of calories absorbed by the body. The ability of fibre sources to reduce after-meal blood sugar levels, lower cholesterol levels, and promote weight loss is based upon its viscosity. A highly viscous blend of soluble fibres has been studied at the University of Toronto for its ability to reduce blood sugar levels (Current Opinion in Lipidology, February 2000).

When taken with water before meals, this fibre blend binds over 600 times its weight in water to form a gelatinous, viscous mass in the stomach, which not only slows down the absorption of glucose, but also induces a sense of fullness and reduces the absorption of calories.

When this highly viscous soluble fibre blend was given at a dosage of three grams to subjects also given 50 g of glucose during an oral glucose tolerance test, it was shown to reduce after-meal blood glucose levels by approximately 60 percent. In comparison, other soluble fibre sources, such as psyllium, had no effect at all.

The most sensible approach to preventing elevations in after-meal blood sugar levels is to eat a low GL diet while also enjoying the benefits produced by highly viscous dietary soluble blends.