They are dark or light green in color depending on the region where they are grown. Though they taste very bitter, they are filled with many beneficial antioxidants and essential vitamins. Bitter gourd is a rich source of cellulose, which adds to you daily dietary requirement of fibre, improving digestion and helping prevent problems like dyspepsia and constipation. Besides it also contains antihelminthic compounds that can kill infectious worms in your stomach. Bitter gourd is an extremely rich source of Vitamin C which helps boost your immunity. A 100g serving of bitter gourd contains just 17 calories making it a great option for those who want to lose weight.