Most who seek to gain weight fail to realize that popular bodybuilding "bulk" diet methods also force the body to add a large amount of fat, which ruins appearance. I cannot stress enough the importance of a proper bodybuilding diet in ensuring that weight gained is in the form of muscle mass, as otherwise, fat will comprise the majority of body weight increase; I am sure you've heard many brag over 20 new lbs of weight in a short period, yet one must ask, 20 new lbs of what? If it's simply fat weight, with three inches added to the stomach, you're not going to improve your mirror reflection, only the scale reading. Again, the goal is to improve appearance as a result of weight gain, meaning you must gain muscle mass, and the only possible way of ensuring such a state is to minimize body fat increase. High calorie, haphazard weight gain diet plans lead to substantial fat accumulation, which is the very opposite of what you wish to achieve -- never forget this!
I suffered from very high body fat levels in my attempt to gain weight, and unfortunately, many others follow similar flawed advice that leads to massive fat gains (easily found on various muscle building Internet sites and bodybuilding magazines). If you are looking to gain fat, simply eat large quantities of junk food, but if you're goal is to improve appearance with muscle, such improvements require specific, detailed diet and weight training rules, none of which originate from "traditional" weight gain tidbits.
Remember, building muscle mass naturally is only possible with proper weight lifting and diet methods, and you risk high levels of body fat through the adoption of common weight gain advice (especially if you decide to use a weight gain powder!). I have personally gained over 60 lbs of muscle mass, and had to burn over 50 pounds of fat due to errors in my weight gain approach; learn from both my success and mistakes through the MuscleNOW bodybuilding program, where I will teach you how to gain weight naturally, without bodybuilding supplements or drugs. The hundreds of muscle building testimonials here at MuscleNOW.com are evidence that my MuscleNOW bodybuilding program is all that you need to gain weight (muscle mass) naturally, without supplements or steroids.