If your cat is not eating, it can be a sign of a number of problems or conditions. Here are some common reasons for this and steps you can take:

1. Medical problem
Pain or illness: Cats can stop eating if they feel pain or if they have a medical problem. This can include dental problems, stomach problems or other ailments.
2. Changes in the environment
Stress or change: Cats are creatures sensitive to change. If there is a change in their environment, such as moving house, adding new pets or even a change in routine, it can affect their appetite.
3. Inappropriate food
Change in brand or taste: If you have changed the type of food or brand he is eating, he may not like the new taste.

4. Temperature or heat
Seasonality: Cats may eat less in the summer when they feel warmer.
5. Stress or anxiety
Emotional causes: Cats can feel stressed or anxious for a variety of reasons, and this can affect their appetite.
what to do
Follow-up: Follow the cat's behavior, does he drink water? Are there any changes in his behavior?

Medical examination: If the cat does not eat for 24 hours or more, especially if it has other signs such as vomiting, diarrhea or a change in behavior, it is important to contact the veterinarian as soon as possible.

Change food: If the food is different, try bringing back the previous food or try different types of food to see if he prefers something else.

Calm environment: Make sure your cat feels safe and comfortable. If there are stressful factors in the environment, try to reduce them.

Personal attention: Take time to play with the cat and give it attention. It can help him feel more relaxed.

Summary
You should not ignore the behavior of a cat that does not eat. If the problem persists, contact your veterinarian for professional advice.