May cause upset stomach, diarrhea, gas. Many people are unable to digest lactose due to a deficiency in an enzyme, lactase, and develop a lactose intolerance. Lactose can be high in fat and is linked to obesity and and heart disease. Ovarian cancer is linked to lactose intake by multiple sources. Excessive added sugar intake is associated with adverse health conditions, including obesity, metabolic syndrome, and inflammatory diseases. Excessive sugar consumption may trigger neuroadaptations in the brain that decouple eating behavior from caloric needs and leads to compulsive overeating. The American Heart Association suggests an added-sugar limit of no more than 24 grams of sugar for most women and no more than 36 grams of sugar for most men each day.