Cats' internal structures differ from humans', which means the nutrients they need for growth and development are different from those in humans. Therefore, we cannot give cats the food we usually put on the table or the snacks we like to eat without any consideration. If we are not careful, their health will be affected, and they may even be poisoned. So we must feed cats scientifically, otherwise it will be too late to regret it when the cat is poisoned and its life is in danger.
We've all experienced this firsthand when raising cats. Sometimes, we're enjoying a snack when our cat comes over, staring longingly at the food in our hand, drooling. Feeling sorry for the cat, the owner might share some of their food, like fruit. However, cats shouldn't eat fruits like grapes because their digestive system can't handle them, and it could even cause vomiting. This is definitely not worth it for the owner. 
So what kinds of food should cats eat less of?
1. Tuna, mackerel, saury, and other blue-backed fish
While these fish provide cats with high-quality protein, they are high in unsaturated fatty acids, requiring a large amount of vitamin E to prevent rancidity. Therefore, if cats do not consume enough vitamin E, the subcutaneous fat accumulated in their abdomen and chest will oxidize and cause rancidity, leading to an inflammatory reaction known as yellow fat syndrome.
Furthermore, there is the issue of heavy metal contamination when consuming tuna or other large fish, so it is best to eat them sparingly.
2. Chicken liver
Chicken liver is also a favorite food for cats. It's highly nutritious, and moderate consumption can be beneficial. However, it's not suitable for cats to eat large quantities over a long period. This is because chicken liver contains a high amount of vitamin A, which cats cannot metabolize quickly enough. This can lead to vitamin A poisoning, causing symptoms such as lameness and tooth loss. Furthermore, chicken liver is high in phosphorus, which can inhibit calcium absorption, potentially leading to rickets and even blood clotting disorders over time.
3. Dried anchovies, bonito flakes
These foods are rich in phosphorus and magnesium, which can easily induce and cause urinary tract stones or urinary system diseases in cats, so try to feed them as little as possible. An adult cat needs about 0.3 to 0.5 grams of salt per day. It is okay to feed them a small amount to improve their taste, but it is best not to feed them salt frequently.
4. Milk
The most common question we hear is about cats drinking milk. Many cat owners know that feeding cats milk isn't ideal, yet they believe it's the only way to provide them with the necessary nutrients. Cats have relatively little lactose-digesting enzyme, which decreases with age, meaning they can't fully digest the lactose in milk, leading to lactose intolerance. Lactose can also be fermented by microorganisms in the lower intestine, producing gas and causing bloating, and even osmotic diarrhea. If the diarrhea is severe and dehydration occurs... that's no joke. Especially for kittens, never feed them milk.
However, room temperature yogurt (cats prefer a temperature of around 30-40 degrees Celsius) is fine to feed them, just like some people can't drink cow's milk but can drink yogurt. We usually give cats goat milk powder or some special milk powder, which are gentler on their stomachs and can supplement their nutritional needs.
5. Seafood
There are many types of seafood that cats love to eat, but shouldn't be fed to them in large quantities. These include shrimp, crab, squid, cuttlefish, octopus, sardines, and filefish. This is because the protein in these foods is difficult for cats to digest, and they also contain toxins that can cause allergies. Adult cats are more tolerant of these foods, but even then, excessive consumption can cause allergies, drooling, vomiting, and diarrhea. In kittens, it can even lead to convulsions and death in severe cases. Sardines and filefish, in particular, contain a strange toxin that cats react to very strongly to. However, because of their strong smell, cats and humans alike find these foods appealing. Therefore, when these types of seafood are present in your meals, never feed them to your cat just because they beg for it. Even adult cats should only be given a small amount; don't cause them suffering out of pampering.
Squid, cuttlefish, and some shellfish contain components that cats may find unsuitable, and excessive consumption can cause indigestion and gastrointestinal problems. Dried squid absorbs water and expands in a cat's stomach, so it shouldn't be given in large quantities. Some seafood can also trigger skin inflammation in cats; before feeding them seafood, give them a small amount first, and only offer more if there's no adverse reaction.
6. Desserts
There is absolutely no need to feed desserts to cats. They contain too much sugar, which cats cannot digest and absorb properly, causing diarrhea. Excessive sugar intake can also lead to obesity and diabetes, and it is bad for cats' teeth, causing cavities.
Other foods that cats shouldn't eat too much of include dog food and human food. It's fine for cats to eat dog food occasionally, but not long-term. Although they have many similar ingredients, cat food is specifically formulated for cats' nutritional needs, containing more protein, specific vitamins, and fatty acids. A long-term diet of dog food will definitely lead to malnutrition. Furthermore, human food contains salt, oil, and bones, all of which can upset a cat's stomach.
It's important to note that this article discusses foods that cats should eat sparingly. The foods mentioned above can be given to cats in moderation, but not in excessive amounts. Some foods are absolutely forbidden for cats, such as coffee, chocolate, onions, and most plants; even trace amounts of these can cause poisoning. Additionally, avoid feeding cats raw meat and fish. Some people argue that cats naturally eat raw meat and fish, but that refers to untamed wild cats. Modern cats, cared for by their owners, have digestive systems very different from wild cats, making them more delicate. Raw meat and fish may contain large amounts of bacteria, viruses, and parasites, which could be fatal to modern cats.
