The popular and much in-demand Kale is low in calories, high in fiber and has zero fat. One cup of kale has only 36 calories, 5 grams of fiber and 0 grams of fat. Kale is great for digestion and helps with elimination due to its great fiber content. It's also full of many nutrients, vitamins, folate and magnesium. 
Per calorie, Kale has more iron than beef. Iron is essential for good health, such as the formation of hemoglobin and enzymes, transporting oxygen to various parts of the body, cell growth, proper liver function and more. Eating a diet high in Vitamin K can help protect against various cancers – it’s also needed for a wide variety of bodily functions including normal bone health and blood clotting. Some reports indicate that increased levels of Vitamin K might help people with Alzheimer’s disease. 
Anti-oxidants, such as the carotenoids and flavonoids help protect against various cancers. One cup of Kale has 10% of the RDA of Omega-3 fatty acids, which helps those with arthritis, asthma and auto-immune disorders.  Eating more Kale reportedly helps lower cholesterol levels. Kale is high in Vitamin C and per calorie it has more calcium than milk to prevent bone loss, osteoporosis and maintain a healthy metabolism. Vitamin C also helps maintain cartilage and joint flexibility. An additional benefit of Kale is that it contains Vitamin A that is great for your vision and your skin as well as helping to prevent lung and oral cancer.