I'm 16 year old boy. I'm very thin and I want to become fat in next 1 month. I want you tell me that what I should eat to become fat. I am ready to anything to become fat.

How about thriving to be a healthy weight, not fat or thin. Being fat isn't any more healthy then being too thin.

Start eating better foods, make sure you get at least 3 good meals a day, healthy snacks in between. Drink at least 8 glasses of water a day. Talk to your doctor about starting a good eating plan and an exercise plan.

You don't mean fat. You mean, "I want to gain weight." There is a big difference.

Not much will happen in one month. Do what Altenweg says, and also ask your doctor about exercises you can do to become strong with a muscular body.

You should eat homemade yogurt with some fruit (strawberries lately) It will help you to gain fat

Where everyone is trying to lose weight, why do you wish to gain weight?
Well, if you mean more mass then start taking proteins with your meals. From personal experience, I can say that it is the easiest and most effective way to gain mass and fat. I ordered BSN true mass, chocolate flavour from www.esportsbuy.com. It really helped, hope it helps you too. I'm sending the link for your reference. http://www.esportsbuy.com/health-nutrition/4283-BSN-TRUE-MASS.html