How can i lose 20 pounds (lbs). in 10-20 weeks and stay that way?

Can be done!: No magic answers here, but it can be done. Find a logical eating plan you can stay with, and increase your activity. Read ann fletcher's book "thin for life, " and google up the national weight control registry to learn about the habits of people who lose - and keep the weight off. Smart phones have great apps (myfitnesspal, etc) that can help you keep track. Consider weight watchers. Good luck.

Diet AND exercise: Make sure you exercise at least 90 minutes a day, don't skip meals, avoid soda, juice, dairy, alcohol and fried foods. Eat a healthy well balanced diet! also water, organic vegetable broth, green leafy vegetables, natural pickles, apples are great to fill you up so you dont feel hungry and they are very low in calories.