Pineapple juice is low in fiber but high in sugar, and excessive consumption may result in weight gain or illness. Some persons may have heartburn or reflux as a result of this beverage's interaction with drugs. Weight loss products containing pineapple may contain acids that can be harmful when taken in large quantities. A study conducted by the University of Hawaii at Manoa found that drinking pineapple juice provides less calcium than milk. Also, pineapple contains bromelain, which increases the breakdown of proteins in your body. This can lead to intestinal problems if used frequently or for long periods of time. According to research published in the Journal of Agriculture and Food Chemistry, eating fresh pineapples daily can increase the risk of kidney stones because of the potassium content. However, dietary guidelines recommend more potassium intake for reducing blood pressure and preventing kidney stones. Therefore, moderate intake of fresh pineapple is acceptable but excessive intake should be avoided. Fresh pineapple has more antioxidants than canned pineapple because it contains more vitamin C and carotenoids. However, both types of pineapple contain about the same amount of sodium. Too much sodium can cause water retention and lead to urinary stones. People who consume large amounts of pineapple may need to reduce their intake of other foods with high acidity levels to prevent any possible symptoms from arising.