book identification about kid turning into plant

Question

I am having difficuly rememering the title of a book i read when i was in grade school. I recall reading a book about a kid who was slowly turning into a plant due to his science fair project, i do not know much more of thestory line but i do remember he hated liver and that was the main ingredient in his concoction, he dipped his feet into a puddle and roots grew out of his feet, i also believe he may have been adopted, I hope this helps to identify the book.

Answer 1

This sounds like Top Secret by John Reynolds Gardiner:

Google Books summary: Despite the disapproval of his parents and his formidable science teacher, nine-year-old Allen determines to do his science project on human photosynthesis.