Sugar has a similar effect on the brain to pain-killing drugs like morphine and other opiates. These type of drugs produce instant feelings of pleasure, calm and satisfaction, making them incredibly addictive. Once food manufacturers found this out, they began producing food full of sugar to enhance the experience; including almost all processed food, alcoholic and soft drinks and even so called 'healthy' food such as breakfast cereals.
Many of us turn to something sugary for energy. It is a form of energy but a bad type. You will have a quick burst of energy after eating it but after about 10 minutes you will feel even more tired that you did before. The sugar quickly hits your bloodstream, creating a rapid rise in blood sugar, you then crash, leaving you exhausted.
Sugar is big business with a massive marketing campaign, so it's able to target us from a very early age, making addicts of us all.