ObeseCalorie:
What's the best way to do it? Is it enough to eat nothing till like 3pm? Or should I not eat for a whole day or more?
Your profile says you are a 48 year old woman who is 187 lbs and 5'5".
Personally, I wouldn't recommend messing with your metabolism.
Short, heavy older women approaching menopause need to be very careful when gaining. Your metabolism is already lowering, menopause will mess up your hormones, and your bones and joints are at an increased risk for damage.
You can still gain safely, but you should be careful not to gain faster than your body can tolerate it. Otherwise, you run the risk of not gaining as much as you could gain or needing to lose weight for health reasons.
Be patient. You are already fat. You'll get fatter in due time.