There was too much fat in the stir-fry I ate, and now I have a sore stomach.
The stir-fry I had was too fatty, and made my stomach hurt.
to take in で「体内に取り込む・摂取する」と言えますが、この場合は次のように言った方が自然だと思います。
ーThere was too much fat in the stir-fry I ate, and now I have a sore stomach.
「食べた炒め物が脂っこくてお腹が痛い」
stir-fry で「炒め物」
to have a sore stomach で「腹痛がする」
ーThe stir-fry I had was too fatty, and made my stomach hurt.
「食べた炒め物が脂っこくてお腹が痛くなった」
fatty で「脂肪過多の」
to make one's stomach hurt で「お腹を痛くする」
ご参考まで！
カナダ 
