I'm very underweight. I eat four meals a day with loads of high calorie drinks (at the moment including at least one Ensure Plus supplement) in between.
I've been underweight to some degree almost my entire life, but since I got sick I've ranged from being just into the healthy weight range down to a BMI of 12 - which I think is where I am now although I've stopped weighing myself because it just ends up reminding me of how I need to gain.
I have the odd occasion where I have bad stomach pain and miss a meal, but I usually manage to eat my four meals plus drinks everyday, I don't do any exercise except walking my dog for around half an hour a day. I do eat some low calorie foods (fruit and veg etc.) but I deliberately try to eat high calorie foods (peanut butter, chocolate, full fat milk, etc.). I can only eat small portions. I know this is the problem - I simply can't manage a normal sized meal. But I consistently eat my small, snack-sized meals and high calorie foods, so sometimes I find it hard to understand why the weight just won't go on.
What really confuses me is that so often I hear of or read about people who claim they only eat low calorie foods - that they live off fruit and veg and fish or something - or people who say sometimes they don't eat all day, or just eat once a day. When I hear things like this it just makes me think how on earth do people eat like this and yet not end up as underweight as I am.
I never feel hungry (don't know what hunger feels like), I always eat way past the point of being full, and I eat loads of junk and nice tasting foods so I never deprive myself of anything I like to eat. If I could somehow sell and market my weight loss skills I'd make a fortune.