Eating too much sugar not only makes you gain weight, but also increases the risk of diabetes, kidney stones, gout, heart disease, and even many types of cancer. The World Health Organization (WHO) recommends limiting free sugar intake to less than 10% of total daily energy, which for lightly active adults is about 45 to 50 g of sugar. 50 g of sugar may sound like a lot, but unfortunately, once it is turned into food, it will seem like too little.