I agree entirely with everything Ruth and Lilith have suggested. Back in 2014, we had a cat dumped on the allotments. She adored human company, a lost soul. Anyway, boy could she eat, 4 pouches down the hatch without lifting her head. I named her 'Chunky', and to say my cabbages were well fertilised is an understatement. She was/is a lovely gentle soul. Anyway, it's long story which I won't go into, but I couldn't take her home, had three cats at the time, and eventually she was found a wonderful home by Cat's Protection. Her appetite and pooping continued to be gargantuan, but after a few weeks of regular feeding, she seemed to realise she wasn't going to go hungry again. Her appetite settled down, her weight balanced and, when last seen she was a very healthy, contented cat. Give it time, he is a lucky little chap to have you as his new slave.
Issi
p.s. had to edit original reply. Blame Gandhi and his keyboard draping
