Ok, first of all, pay attention to your diet and try to eat more and less meals a day. Don't eat or try to eat foods high in sugar and starch. Eat more fruits at ordinary times, remember not to eat bananas. Protein content is high. It is best to eat less rice and more fruits and vegetables in the evening. If you don't want to exercise, you can go out for a walk in the evening after dinner 1 to two hours. If you want to walk fast, it won't work. Hold on at least 1 to two hours. Make sure you are effective, and going out every day is also good for your mood. Besides, don't sit still immediately after eating. It is best to do something with a small amount of activity, and be careful not to be too intense, otherwise you will get appendicitis. Let me tell you another thing, drink less carbonated drinks (coke, sprite and so on). 2, losing 20 pounds in 3 months is not a challenge, as long as you can persist, control your mouth, and be diligent, it is easy.