Why eat watermelon skin instead of watermelon pulp? ! This is because the watermelon we often eat eats vegetative tissues (mainly in pulp), while the sugar in watermelon is mainly stored in vacuoles, so many people only eat pulp. Watermelon skin is mainly a protective tissue. Because it is lack of sugar outside, it tastes bad and unsanitary, so most people eat watermelon pulp instead of watermelon skin (of course, a few people eat watermelon skin).