I found this at http://www.intense-workout.com/weight_gain.html
Its very basic and to the point:
How to gain weight
Weight gain is something that isn't easy to do and you probably know this already. I know first hand because it is something I have to do every day. I am an ectomorph by genetics, which is the "skinny body type" and the one with the fast metabolism which makes gaining so hard for guys like me. The key to weight gain is to do everything BIG. You have to eat big, to lift big, to get big. Say that over and over again in your head until you fully understand it. A lot of people think weightlifting is the key to gaining weight, and I won't argue, it is an extremely important part. BUT, there is another thing that is just as important when it comes to how to gain weight, and that is your diet.
So, to put it as simply as possible, there are 5 simple steps to how to gain weight, and here they are:
1) Count how many calories you eat in a normal day. Don't change anything, just eat like you normally would and count how many calories you consumed. This is an extremely important step, so try to be as exact as possible. Also, weigh yourself.
2) Starting the day after you counted calories, eat 500 calories MORE then you normally do. So, lets pretend that the day you counted calories you counted 2000. For the rest of the week, you would now eat 2500 calories a day. Instead of eating 3 big meals a day or eating all day all the time, spread those calories out over 5-6 smaller meals. Eat one meal every 2 and a half to 3 hours. To get big, you have to eat big! Remember that.
3) Weightlifting! Get in the gym and lift! This is another important step to how to gain weight, so make sure you are doing it correctly. For more information on weightlifting workout routines and splits, read the workout routines and splits section.
4) At the end of that week, weigh yourself. You'll notice your gaining just after one week! Now, don't expect to see a 10lb increase. Gaining anymore then 1 or 2 pounds a week is unhealthy and means your putting on way to much fat. So look for 1 or 2 pound gains at the end of the week. Don't sound like much? You can be gaining 5-8 pounds a month!
5) Heres an important one. At some point, you will stop seeing weight gain. At this point, you will have to eat even more. So, when you stop gaining for at least 2 weeks, it means it is time to start eating an extra 250 calories a day. Every time you see you haven't gained weight for at least 2 weeks, add an extra 250 calories.
More tips for how to gain weight (extremely important!)
- Stay away from fat! Eventhough weight gain is your goal, you don't want to be gaining fat. Get rid of the chips and candy. No more fast food, nothing fried. Stick to high protein low fat foods like tuna fish (and other seafood), chicken breast, turkey, lean meats, fruits and vegetables etc. (For more information, read the diet and nutrition section.
- WATER! Drink water! Drink around a half gallon a day, more if you can. Yes thats alot of water, but its that water that will give you the energy you need to gain that weight!
- Sleep! YES! Sleep! The easiest, yet most over looked step. Get atleast 8 hours of sleep a night. Your gonna need it!
Now the concern some people have about how to gain weight, is how to do it without putting on extra fat. Let me tell you how, YOU CAN'T! Unless you are using steroids, it is basically impossible to gain weight without putting on a little bit of extra fat. But hey, you want to see some weight gain right? Well then who cares about the little bit of extra fat you might put on while gaining. You will be able to burn that off later on, right now gaining is your main concern, so that is all you need to worry about.
