What is the fastest way to gain weight?

Eat lots of high-fat foods and don't exercise. It's your metabolism. Look at your family photo album and see who is thin in the pictures. It's the gene pool! Eat well, but don't eat bad fats and certainly exercising (going jogging, biking, fast walking) is good for the body and will put muscle on you and get your heart rate up. In time you'll get to a weight suitable for you. I know I use to be under-weight when I was young and now I'm always fighting the battle of the bulge now!

For beginners

1. Eat enough calories more than 2800 per day

2. Start working out lift weights run get your body in shape

3. Keep doing that I bet u that you will gain 1-3 pounds per week....