how can I get my child to gain weight and eat more?

my daughter has just turned 3. She was born two weeks early weighing in at 4pounds 9 oz. She has always been slow on the weight graph although perfectly developed. She was prescribed SMA High Energy when she was one to help with her weight gain which only made her sleep less sleeping less than 5 hours a night in sections. I took her off this after 8 months and she started to eat and sleep more. She has slept all night since she was 2 and a half but still eats very little. I cant persuade her to eat, I try all sorts of food from healthy to junk. She might eat little snacks all day but meal times are always small bites. We end up in tantrums because she refuses to eat whats in front of her and sometimes will sick it back from crying because she didnt want to eat it.
We have been through all the tests from cystic fibrosis to metabolism and all come back perfectly fine. she is a perfect active and hyper little girl perfectly proportioned and developing to schedule. I was similar when I was her age although I weighed a little more than she does now. I just cant stop worrying about her weight and hate seeing her bones all the time. I need help!

[Renee Radenberg]

Both her weight and height are below the 5th percentile for her age. She is petite. It can be very frustrating when your child has no interest in food. Suggest decreasing the snacks all days so she is hungry at meals, and replace her milk at meals/snacks with Pediasure, or milkshakes (milk and ice cream blended), or yogurt smoothies (yogurt, ice cream, or frozen fruit-if she accepts it- blended) for additional calories and protein for weight gain. Recommend giving her a chewable children daily multi-vitamin due to her eating habits. Try engaging her in the kitchen more. Have her help you with planning and preparation of food, and setting the table. Hopefully this will increase her interest in food. The most important is to relax at meals. Slowly introduce new foods. Sometimes it takes 5-9 times to introduce a food to a child that they will accept, however, if they do not want it you have to not make a fuss and let it go. Hoped this helped you.

[EmmaRichards]

Thank you very much for your response. I have been researching Pediasure and its looks quite difficult to obtain it in the UK. Any advice on where I can get hold of it? I have been looking at Nutridrinks.co.uk Are they just as good as Pediasure?
Thank you for the drinks idea too, I will be definitely trying it!

[Renee Radenberg]

In the UK it is Paediasure which you can get through Nutridrinks.co.uk. Do not recommend ensure or the other supplements they sell. The cheapest way is to make your own milkshakes or yogurt smoothies.