Watermelon is not very high in fiber. It contains about 0.4 grams of fiber per 100 grams. Therefore, it is not considered a high-fiber fruit. However, its high water content may support digestion and make it a refreshing snack option. People who want to increase fiber intake should also include stronger fiber sources such as vegetables, whole grains, legumes, oats, chia seeds, and fruits eaten with their skins.