Onion has a certain weight loss effect, but it needs to be combined with other diet control and reasonable exercise to achieve better weight loss effect. Onion is a common vegetable with tender meat, rich juice and slightly spicy taste. It can be eaten raw, fried, and can play a role in losing weight, mainly because it contains almost no fat and is a low-calorie and high-fiber vegetable. Eating during weight loss can increase satiety and reduce the intake of other high-calorie foods. Onion also contains glutathione, lutein and other ingredients, which has a strong antioxidant effect, can improve liver function and promote fat metabolism. Onions contain a lot of vitamin C and minerals, and vitamin C can promote digestion and absorption. In addition, the epidermis of onion is also rich in polyphenols, which has high antioxidant capacity. After this substance is absorbed by the human body, it can quickly reduce fat and has a certain weight loss effect.