Your taste buds can’t distinguish between naturally occurring sugars, which are found in foods such as fruit and dairy products, and added sugars, which manufacturers add to foods such as soda and candy. From a nutritional standpoint, however, there is a big difference between these sugar sources. Foods that contain naturally occurring sugar tend to be nutrient-rich, and thus, provide more nutrition per bite.
In contrast, many foods that contain lots of added sugars provide little else. The calories in sugar-laden foods are often called empty calories because they provide so little nutrition.
For example, a glass of 100% orange juice is rich in vitamin C, potassium, and other wonderful nutrients. In contrast, orange soda doesn't provide any nutrition other than a lot of calories from added sugars.