Glycemic Load

Glycemic Load (GL)

Low glycemic index (GI) and glycemic load (GL) carbohydrates result in a slower, more gradual rise in blood sugar, as illustrated in the figure above.

Different GI and GL foods thus influence blood sugar and insulin levels over time.

The glycemic index reflects how quickly a food raises blood sugar, while the glycemic load (GL) considers both the quality (GI) and quantity of carbohydrates, providing a more complete picture of its effect.

Foods with a high GI (≥70) and high GL (≥20), represented by the red curve, cause a sharp rise in blood sugar, peaking about 30 minutes after consumption.

This rapid increase triggers a significant insulin response, which then quickly lowers glucose levels, often below baseline, potentially causing reactive hypoglycemia:

This blood sugar 'rollercoaster' is common with refined or processed carbohydrates that are quickly absorbed.

 

Foods with a medium GI (56–69) and medium GL (11–19), represented by the yellow curve (Figure 1), result in a more moderate rise in glucose and insulin levels, with a lower peak and a slower return to baseline.

This intermediate response is characteristic of foods with a balanced carbohydrate composition, providing sustained glucose supply and avoiding extreme fluctuations.

Foods with a low GI (≤55) and low GL (≤10), illustrated by the green curve (Figure 1), have only a minimal effect on blood sugar and insulin levels.

The gradual increase and sustained glucose availability are characteristic of high-fiber and complex carbohydrate foods, which help stabilize blood sugar and minimize excessive insulin release, supporting metabolic health.

 

However, GI and GL alone are not sufficient for dietary decisions — a truly effective diet can only be developed through a complex evaluation of composition, nutrient density, and individual response.

This graph illustrates how foods with different glycemic indexes (GI) and glycemic loads (GL) affect blood sugar and insulin levels within two hours after eating.

 

The curves show the following

High Glycemic Index (Red curve)

• Values: GI ≥ 70, GL ≥ 20.
• Effect: Blood sugar rises sharply and steeply, almost reaching 2 g/L in just 30 minutes.
• Consequence: The body reacts to this with a large release of insulin (up to 140 µU/mL).
• Then, blood sugar levels drop rapidly, often falling below fasting levels (reactive hypoglycemia), which can cause feelings of hunger.

 

Medium Glycemic Index (Yellow curve)

• Values: GI 56–69, GL 11–19.
• Effect: A more moderate rise, peaking later, about 1 hour later.
• Consequence: The insulin response is also more moderate (about 75 µU/mL), and blood sugar returns to normal levels more gradually.

 

Low Glycemic Index (Green curve)

• Values: GI ≤ 55, GL ≤ 10.
• Effect: Blood sugar rises slowly and only slightly.
• Consequence: This requires the least insulin (barely rising above the baseline of 10 µU/mL) and provides more stable energy levels in the long run.

 

In summary

Low GI foods (green) help maintain stable blood sugar levels, while high GI foods (red) can cause a sudden "sugar shock" and subsequent feelings of fatigue.

 

Further details..