Maintenance of blood sugar levels is an important part of weight management. When we eat, our body converts carbohydrates into glucose (sugar) needed for energy. All carbohydrates, including bread, pasta, cookies, fruits and veggies, elevate our blood sugar levels, triggering a surge of insulin which stops the body from burning fat and calories. This insulin spike can also lead to a "sugar crash," leaving us to feel lethargic, fatigued, irritable, etc. As a result, we crave more food, often sugar, to reverse this energy slump.
One way of measuring the effect of carbohydrates on our blood sugar is to look at the glycemic index (GI). The higher the GI a food has, the more it raises our blood sugar. Many foods and grocery stores (such as Whole Foods) list the GI on their labels.