Watermelon nutrition has everything you need to beat the soaring tropical summer. Rich in electrolytes and water content, melons are nature's gift to beat . May 10, Watermelons are mostly water — about 92 percent — but this refreshing fruit is soaked with nutrients. Each juicy bite has significant levels of. What does this do for the body? While nearly 92% of watermelon is water, the 8% left over is rich in this compound, protecting and nourishing the heart, prostate. Aug 20, That's because watermelon is rich in an amino acid called L-citrulline, which the body converts to L-arginine, an essential amino acid that helps. May 25, Watermelon is the richest known dietary source of the amino acid citrulline. The highest amount is found in the white rind that surrounds the. Jul 1, Watermelon is full of vitamins A and C, and that's not all. This food has some other serious superpowers up its sleeve.