A question we get asked a lot is “How do I gain weight?”
I can tell you the answer in 2 words: Eat more.
Many people think that lifting weights makes you gain weight, but it doesn’t! Eating more calories causes you to gain weight. And if you are eating the right food, then then lifting weights will ensure that the weight you gain is muscle. You could spend every day in the gym, but if you aren’t eating enough, then you won’t be gaining any weight!
You need to write down every single thing you eat for a few days, and average it out. Then add 300-500 calories to that average, and make that your new daily calorie goal. This should allow you to gain about 1lb per week. You want to try gaining 1lb-2lbs per week, anything more than that will just be fat. The website I use to find nutrition info for food is Nutritiondata.com