Foods considered high on the glycemic index include simple sugars, white bread etc. These are considered "simple carbohydrates." They are quickly digested which cause blood sugar levels to spike and fall rapidly. This is known as a sugar high and sugar crash. Low glycemic foods such as quinoa, brown rice etc. are considered complex carbohydrates. Low glycemic foods are digested more slowly and keep blood sugars steady. These foods will provide a more consistent source of energy and help keep you full between meals.
Foods with a low glycemic index have shown to...
Improve blood sugar in people with diabetes
Lower insulin levels
Improve cholesterol levels
Improve body fat percent in the body
Reduce risk of type 2 diabetes
Decrease the risk of heart attack and stroke,
There are some foods that are considered higher on the glycemic index such as some fruits and vegetables. However, in moderation, these foods are ok as they contain high fiber which binds to the sugar molecules and minimizes the insulin spike. Generally, avoid all processed foods as much as possible as they contain high levels of simple carbs such as sugar, are higher in fats and empty calories.