Grown in the USA, the sweet orange is the world's most popular citrus fruit. The flesh of the sweet orange contains a blend of sugars and acid. Sugars form during the heat of the day and the acid forms over cool nights. The best regions to grow oranges are those that demonstrate wide and daily temperature variations. Orange peel is loaded with vitamins and minerals, many use it to help protect the body from cancer, fight respiratory ailments and enhance weight loss.