Japanese by Example
Learning through examples in manga

Feeling you've gained weight with 〜気がする

ふらいんぐうぃっち » Volume 2 » Page 136

Nao sees Makoto’s cat, Chito. She stops to pet the cat when she notices something.

なお:
「もしかして(ふと)った?(まえ)より(おお)きくなった()がするねー」
"Could it be you've gotten fatter? I feel you've gotten bigger than before."