PDA, Eating and Drinking

Hi, 

While we don't yet have a diagnosis, several professionals are sure that my daughter (9) has ASD, with PDA traits. We have discovered over the years that she is generally copes much better when she eats plenty of snacks and drinks lots of water (not surprisingly!). However, since going back to school we are really struggling to get her to eat any snacks (though she is still eating meals) and she is almost refusing to drink anything at all. Unsurprising, she is really struggling at school and her meltdowns at home are becoming more frequent and more severe. I'm really conscious that just badgering her to drink won't work. Even though she has one on one TA support almost full time who remind her to drink often, she says she struggles to drink as she doesn't feel thirsty so it feels uncomfortable. She also says that she doesn't want her snacks because she doesn't feel hungry, and while this is probably true, as I know she struggles with interoception, she has also confided in her TA that she doesn't want to eat her snacks at school because she is fat (she absolutely is not). She has also told me that people tell her she's weird because she needs to eat all the time. 

I have tried to reason with her that she NEEDS the food and drink to sustain herself, help her stop becoming overwhelmed at school, regulate herself, etc, but she doesn't understand the logic. Please can someone suggest ways of getting her to eat and more importantly drink what she needs!!

Many Thanks in advance.