An increase of about 500 kcal per day will result in an increase in body weight by about 0.5 kgs per week. Try to eat around six times a day, with each meal containing protein, starch, vegetables, and fat." A good example of such a meal would be a turkey sandwich, whole-grain bread with mayonnaise, tomatoes and a fruit smoothie. Read on from www.webmd.com/diet/features/how-to-gain-weight.
I'm havin the same problem only I'm 14. Nothing will work for me! I have an extremely high metabolism no matter what I eat or how much I eat I can't gain weight! Sometimes I feel like the only way is to cut me open and physically put fat in!!
You can buy weight gainer protein powder at your local health store. Mix with milk and you have a perfect shake. Have two shakes a day and your consuming 2000-3000 calories in just those two shakes. Don't forget having other meals. You should notice weight gain your first week