yo bro, do your best to eat high food value items like avocado, salmon, red meat (watch your sat fat intake), nuts, peanut butter; cheeses,eggs- stuff that is densely nutritious that will keep you nourished and provide lots of high quality calories. Starches and sugars are used by the body quickly and when you are chronically ill as you are- your body is gobbling up those calories just to function (breathing for example). there are starches called complex carbohydrates that are healthier (oats for example) but you have to figure out if it takes more energy to digest them then they're no value to you. Use one of the dieting websites like "fat secret" or "calorieking" as they have nutrition information on countless food items. You don't want to get fat because then it just burdens your cardiopulmonary system even more- keep yourself motivated and healthy and you'll do yourself well. cheers mate and full steam ahead!