This test demonstrates how well a person handles carbohydrates. Carbohydrates come from plant sources, including vegetables, fruits, grains, and breads. Eating foods that keep blood sugar stable will maximize energy throughout the day and prevent disease.

In this test a person is asked to fast from food for 10-12 hours before the initial blood draw. After the initial blood draw, the person drinks a serving of fruit juice, which is the simplest form of carbohydrates (sugar). The person’s blood sugar is drawn again, every 30 minutes for 90 minutes, to check the response to the juice. The results are graphed out and compared to the normal range.

When the blood sugar drops too low, the person is said to be a fast oxidizer. This means the person breaks down (oxidizes) food too quickly. The recommended diet for this person needs to contain larger amounts of foods such as proteins and fats that are broken down slowly. This will help keep the person’s blood sugar stable.

In contrast, when the blood sugars stay too high on the Modified Glucose Tolerance Test, the person is a slow oxidizer. Slow oxidizers break down food too slowly so the blood sugars stay too high. The recommended diet for this person needs to contain plant based foods such as whole grains, fruits and vegetables to keep the person’s blood sugar stable, since these foods are broken down the easiest. (See figure 1.)

FIGURE 1. The Modified Glucose Tolerance Test demonstrates how well a person handles carbohydrates.