By combining a mix of proteins, fats and carbs in our meals and eating on a regular basis we avoid blood sugar lows.
Why is this important?
GL stands for glycemic load and is a precise measurement of what food does to your blood sugar levels. Foods with high GL (refined carbs and sugar) have a greater affect on your blood sugar level than foods with a low GL level (whole foods such as brown rice).
Constant spikes in blood sugar, caused by high GL foods are what cause weight gain and a number of illnesses.
When your blood sugar level goes high, insulin is released into the blood to remove the glucose (sugar). Some of the glucose goes to the brain and the muscles, but if you've eaten more than you need, the remainder goes to the liver. The liver then turns the excess glucose into fat where it is stored in the nearest place possible. Insulin is therefore the fat storing hormone.
Afterwards, the blood glucose levels drop, and this trigger hunger and also the release of stress hormones to get you hunting for more food, thus your craving for sugar and carbs kicks in.
The sugar cycle
When your blood sugar drops you feel tired and hungry. If you refuel with fast-energy-releasing high GL carbs, you then cause your blood sugar to rise rapidly.
Your body doesn't need this much sugar, so, as before, it dumps the excess into storage as fat. Then your blood sugar level goes down again. This is how you enter the vicious cycle of yo-yoing blood sugar that leads to tiredness, weight gain and sugar cravings.