Sweet potatoes contain "gasification enzyme", after eating will sometimes occur heartburn, spit acidic water, bloating gas and other phenomena. As long as you do not eat too much at once, and with rice and noodles with eating, and with salty vegetables or drink some vegetable soup can be avoided. It produces acid in the stomach, so it is not suitable for patients with stomach ulcers and excessive stomach acid. Note: Rotten sweet potatoes (sweet potatoes with black spots) and sprouted sweet potatoes can be poisonous and should not be eaten. Sweet potatoes and other root vegetables contain a lot of starch, can be processed into vermicelli consumption, but the production process will often add alum. If too much consumption will lead to aluminum accumulation in the body, is not healthy.