Carbs give you energy in the form of glucose (sugar). They also give you lots of vitamins and minerals that your body needs. But not all carbs are created equal. Complex carbs are the healthy variety. These carbs include foods like whole grains (brown rice, oats), legumes, whole grain breads, and whole grain pastas. Unlike simple carbs, they cannot be absorbed into your blood until your body breaks them down. This means the sugar is released into your blood more slowly. Simple carbs, like cakes, cookies, candy, and other sugary foods can cause your blood sugar to quickly spike, and then crash. Simple carbs are often much higher in calories and much lower in nutrients than complex carbs.