Glycaemic Index Explained

The glycemic index (GI) is a measure of the capacity of a food to increase blood sugar levels.

It scores foods on a 0–100 scale with a ranking of low, medium, or high.

These are the score ranges for the three GI values:

• Low: 55 or less
• Medium: 56–69
• High: 70 or above

To explain, foods high in simple carbs or added sugar are broken down faster in the bloodstream and have a higher GI because of the quick release of sugars into the blood stream from where it is taken into the cells in the presence of insulin.  The rate at which foods raise blood sugar levels depends on three factors: the types of carbs they contain (simple or complex), nutrient composition (fat, protein, fibre), and the amount eaten.

Foods high in protein, fat, or fiber take longer to digest and so have less of an effect on blood sugar levels and typically a lower GI.

Other factors that influence GI value are food particle size, processing (raw, cooked, ripe, unripe), and cooking methods (boiled, baked, roasted, fried).

GI is a relative measure that doesn’t take into account the amount of food eaten. To solve this, the glycemic load (GL) rating was developed.

The GL is a measure of how a carb affects blood sugar levels, taking both the type (GI) and quantity (grams per serving) into account.  Calculated by multiplying the carb quantity in grams by the GI and dividing by 100, like the GI, the GL has three classifications:

• Low: 10 or less
• Medium: 11–19
• High: 20 or more

After the consumption of carbohydrate containing foods, the body signals the pancreas to secrete a hormone called insulin to break it down. Insulin acts to lower the body’s sugar levels. When the blood sugar levels decrease to a particular level, the brain is sent a signal and you become hungry again.  Therefore, eating a diet of mainly high GI foods leads to increased hunger, weight gain, elevated cholesterol levels, insulin resistance and eventually type 2 diabetes.  This is why the Glycemic index is an important metric to track.

To visualise the concept of GI, imagine a runner.  To sprint, the runner needs a burst of energy after which there is extreme tiredness and a need to replenish energy resources.  To run a marathon, the runner will need a steady flow of energy to keep going till the distant finish line.  High GI and low GI foods are like the sprinter and the marathoner.  No prizes for guessing which is better!  You might need both, but for long term health, the slow and steady release of sugars into the blood stream is more sustainable and healthy – low GI foods are what we should be eating!

In its commitment to your health, Conscious food has made available the various options for rice and other grains each with its own GI.

* Bhajiyas can be an occasional treat – fried food is generally not healthy.