1. When a cat is in a new environment and feels uncomfortable, it will have a poor appetite. Once it adapts to the environment, it will recover.
2. Frequently feeding cats snacks and meat supplements can also lead to picky eating habits. You should reduce the amount of snacks you give them. 
3. When a cat has an upset stomach or suffers from gastrointestinal disease, it may also become picky about food. Owners can feed their cats some probiotics to regulate their digestive system.
4. If a cat doesn't get much exercise and burns little calories, it may become a picky eater. Owners should interact with their cats more often or take them out for walks more frequently.
5. If a cat's stomach or intestines are filled with too much hair, it can affect its digestive system and lead to a decreased appetite or picky eating. You should feed the cat some hairball remedy or cat grass to help expel the hair.
