[Dynseli]

You can take as much protein powder as you want, but it has to be diluted in a lot of water, and not done for an extended period. Natural peanut butter and jelly sandwiches will help you gain. Fruit juice too. You don't have to overeat to gain weight, but you have to avoid being hungry. Resistance training will help, but being physically overactive makes it nearly impossible to eat enough for gains. Everyone had good advice on here. AchievingConfidence has a good point, because resistance exercise causes an increase in appetite. Too much refined sugars and fats are bad. Unrefined is good, as long as it is balanced right. Listen to how your body deals with food.

Eat your favorite foods, and learn how to prepare the foods you like that are convenient. Eating a lot is a mindset, and over-worrying about what to eat can be restricting. Don't worry about if how many meals a day or how much food has an effect on metabolism. In my opinion, going strictly for organic can hold you back, because it restricts your diet by money and refusing otherwise good food. You can consider growing a banana or avocado tree, if you have a green thumb. That can easily give you a lot of calories a day for a while. Easier said than done. Good luck.