Child Specialist Indirapuram #How is junk food harmful to body? Most of these foods have poor nutritinal quality with high carbohydrates and fat content along with high in sugar or salt.On the contrary they are low in proteins, vitamins and minerals and other micronutrients. The nutritionally imbalanced diet often leads to rapid weight gain and obesity. Some of the additives used in ultraprocessed food may increase risk of cancer.High sugar content of junk foods and drinks may lead to dental caries.