Here are the best tricks to gain weight
• Take as many calories as possible in liquid form. At the risk of sounding kind'a gross here, all of your food is liquid. That is, your stomach has to convert solid food to liquid. You can think of your stomach as a blender. You start chopping up food with your teeth, and your stomach takes over. The more chewing and digesting that your stomach has to do, the less calories are actually available for weight gain. You can get over 1,000 calories from a milkshake, which requires no expenditure of energy to digest. Drink your calories!
• Digest well. If you are like me, with a nervous stomach, keep your eating and digesting environment calm. That food won't do you any good if you don't digest it. Vomiting and diarrhea is not only unpleasant, it's unproductive. Either eat alone or eat with someone who knows not to upset you. Sit down after eating a big meal. Try to avoid lying down, at least for the first half-hour, then you can lie down. Your digestive organs work best when they are vertical, not horizontal. But whatever you do, don't stay on your feet. Give your body a chance to digest. Eating and sleeping are the best things that you can do to gain weight. Babies know this!
• Spread your meals out as far as possible. Get ravenously hungry, and then fill up your stomach. If you get into this habit, rather than grazing, you will physically increase the size of your stomach and you will successfully lower your metabolic rate.
As strange as it seems, a lot of advice from fat people is just wrong. Trying to gain weight from beer or alcohol is a mistake for a hard-gainer, it usually just upsets your system. Heavy, greasy, fried foods can also be very difficult to digest. I recommend that you stay away from them, or ease into them slowly to become accustomed. The fact is that a lot of people have gained weight slowly and don't really know how it happened. If they did, they probably could control their weight.
Knowledge is power. And size!