Cats may experience gastrointestinal upset, such as diarrhea and vomiting, after eating cooking oil.
Cats that accidentally ingest small amounts of cooking oil usually won't have a significant impact on their health. However, if they ingest larger amounts, it may cause gastrointestinal discomfort, manifesting as loose stools, diarrhea, vomiting, or other abnormal symptoms.

Cooking oil itself is not toxic, but if a cat exhibits severe symptoms such as lethargy or loss of appetite, it needs to be taken to a veterinary hospital for treatment immediately. For your cat's health, it is recommended to cultivate good eating habits, avoiding feeding them too much oil and salt, and choosing a bland diet.