Update;
Thanks to everyone for their inputs. I've been to the vet as many suggested and it turned out that he just overate (probably broke into a neighbours home to feed). After a full day of rest, he went back into his usual shape.
Please note that he gets enough food from us. Just like most cats, he's very food motivated ^^'
I am using boost for lemmy for some time now and am very happy with that app. I've tried jerboa, summit and thunder before but they felt somewhat incomplete at the time I used them.
Update; Thanks to everyone for their inputs. I've been to the vet as many suggested and it turned out that he just overate (probably broke into a neighbours home to feed). After a full day of rest, he went back into his usual shape. Please note that he gets enough food from us. Just like most cats, he's very food motivated ^^'