Foods that can stimulate a cat's appetite include:
1. Fragrant wet food: If your cat has no appetite, it may be because it's tired of the same food or the food lacks aroma, which makes it uninteresting, since cats rely on their sense of smell to eat. During this time, you can feed it fragrant foods such as canned cat food, wet food pouches, or soup pouches, which are all very fragrant and will appeal to the cat. You can mix these into its regular cat food.
2. Meat-flavored cat food: Cats are carnivores, and most cats can't resist the temptation of meat. If you don't want to feed them wet food with a lot of additives, why not make some homemade cat food for them when you have time? It's healthy, nutritious, and your cat will love it.
3. Sweet and sour foods: If your cat has a poor appetite, you can feed it some sweet and sour fruits to stimulate its appetite. These can be given before or after meals, such as strawberries, apples, and pears. They can be cut into small pieces or mashed into a puree. Be careful to avoid giving your cat fruits that are not safe for them, as this may cause them discomfort. 
Possible reasons for a cat's loss of appetite:
1. Decreased appetite due to illness: The first thing to consider when a cat's appetite decreases is the possibility of illness.
2. Dislike of food texture and taste: Cats are very picky about taste. Subtle changes in taste, texture, temperature, etc., that only cats can perceive, can greatly affect a cat's appetite.
3. Nutritional incompatibility: Cats have something like "nutrient sensors" in their bodies. If the nutrients in their food do not meet their body's requirements, cats will readily choose to fast.
4. Too hot: Just like humans, if it's too hot, the body's temperature regulation will cause people to be tense, putting them in a state similar to summer heat and making it difficult to eat. Provide your cat with a cool environment, and don't skimp on air conditioning electricity if necessary.
5. Environmental stress: A stressful environment can affect a cat's appetite. Providing a safe and comfortable environment for your cat is one solution.
