May 10, Watermelons are mostly water — about 92 percent — but this refreshing fruit is soaked with nutrients. Each juicy bite has significant levels of. Jun 20, Watermelon contains a wealth of nutrients, such as vitamins, minerals, and antioxidants, but hardly any calories. A favorite summer picnic fruit. Watermelon is an unusual fruit source of the carotenoid The following chart shows the nutrients for which this food is either.