geking - I am also 5'4" like you and am considered "underweight". I have experimented with food and can not eat a lot of fiber so more of a low fiber diet which will not help me I know -- can not eat a lot of veggies and no salads, no tomatoe sauce, etc, chocolate and/or coffee only when I become too constipated as I get inflammation in the lower sigmoid/ rectal area if I lean towards diarrehea (also have IBS) plus trying to gain a little weight. So, I do eat white bread, and some easy on the gut processed food which I presume now is bad for you. I do drink 2 Ensure Plus a day in addition to my meals but not in my metabolism to gain weight - i burn it off with very little effort. I do not live a sendatory life but I do not get enough sleep and I know that does not help and I can't take sleeping pills.
Sleep problems started with a sick Mom in another state when I was still working and running to take care of her inbetween as she refused to leave her home and come to MA -- she was in NY. I never seemed to fully recover from the few years of just running, running, and finally running on empty.,,,no siblings so all on me.
I also was one of those "experimental " kids that got radiation for an enlarged thymus gland at birth to shrink it but instead it completely destroyed it and the thymus is an infants immune system and again at about age 6 to get rid of the scar tisssue the first created. It was the new mircle cure and unmeasured cobalt and then the doctor finally found out how bad it was and told my Mom i would be dead by age 16 or if I survived I should neer have kids as they would be deformed. My allergist/asthma doc says a lot of my health issues and many drug allergies stem from this cobalt years ago. I recently had a friend die of thyroid cancer who was also a cobalt kid. I have thyroid nodules they are watching and almost died a few years back from a thyroid storm - was in the telemetry unit of the hospital for 4 days as they thought I was going to have a heart attack and was given the radioactive iodine pill that brought my numbers into range. They also think it was the cause of my BC. I walk for my osteoporosis and take Evista as that is the only one I am not allergic to. So, anyway -- I am kind of at aloss re: diet -- I have tried veggies, etc and paid for it colon wise so, yes, I do need help. Right now I want to gain weight but do not have much sugar or dairy. The most I ever weighed was 125 lbs at 9 months pregnant.