You can eat watermelon in small amounts at intervals after eating crab, but it is not recommended to eat crab and watermelon at the same time or in large quantities one after another. If you eat a lot of crab and watermelon at the same time, it may increase the burden on the gastrointestinal tract, and if you are in a special period, eating a lot of crab and watermelon may also aggravate the discomfort symptoms. Crab is a cold seafood food and watermelon is also a cold fruit. If both are consumed at the same time or in large quantities, they may easily increase the burden on the gastrointestinal tract, thus causing digestive reactions, which may manifest as nausea, vomiting, abdominal pain, bloating and diarrhea. For women in menstruation, eating crab and watermelon at the same time may aggravate the symptoms of dysmenorrhea and cause discomfort. Crab is rich in protein, unsaturated fatty acids, vitamins, calcium, phosphorus and iron, which are beneficial to the human body, while watermelon is rich in water, fructose, amino acids and other substances, moderate consumption of heat, refreshing and thirst quenching. Therefore, you can choose to consume watermelon 2-3 hours after eating crab to avoid discomfort. In particular, it is not recommended for people with weak stomach and intestines to consume crab and watermelon at the same time, so as not to aggravate the symptoms of stomach cold and be detrimental to the health of the gastrointestinal tract. In addition, it is not recommended to eat crab together with cold foods such as melon, kiwi, grapefruit, or drink a lot of ice water or cold drinks after eating crab, which can also easily cause digestive discomfort.