Squealing when eating!

Poppy took to solids really well and will eat pretty much anything. But fun mealtimes have now become a nightmare!!! She often squeals from the moment I put her in the highchair and doesn't stop until she comes out! Its not a cry but a high pitched squealing scream noise. Sometimes she'll eat a few mouthfuls quietly like she used to and I think phew 'the noise' has gone but then she starts up again. She used to be really good if I took her out for lunch, she'd sit in a highchair and have her food and then just watch everyone. Now though I feel like I can't take her out to eat - my mum and I took her go pizza express last week and she squealed the whole time and mum was mortified as everyone was staring at us!!! The thing is it's not because she doesn't like the food because she's eating happily while making noise. Some days it really goes through me and gets to me. I'm worried that it's now become a habit! Does anyone else's LO do this? I've tried using toys or finger foods as a distraction and sometimes they work for a while.

xx