6 human foods that make a great treat for your cat and 7 that you should never feed them

• Cats cannot eat chocolate, milk, cheese, peanut butter, grapes, bread, or popcorn.
• But cats can have up to a teaspoon a day of bananas, strawberries, blueberries, and apples.
• Just make sure that your cat gets 95% of its calories from cat food and only 5% from snacks. 
• Visit Insider's Health Reference library for more advice.

There are plenty of human foods that your cat can eat, but there are also some that can be dangerous. Of course, the safest option for feeding your cat is to give them cat food — but it's okay to give your cat a small treat from time to time. 

Just remember that about 95% of calories in your cat's diet should come from cat food while the remaining 5% can come from treats, including human food, says Carol Osborne, DVM, an integrative veterinarian at Chagrin Falls Pet Clinic. 

It's important to be aware that many human foods contain sugar, which could upset your cat's stomach. Because of this, be sure to limit your cat to about one teaspoon at a time of any sugary fruits.

Here are six foods that you can feed your cat and seven that you should avoid. 

Foods you can feed your cat

Here are six human foods you can feed your cat in reasonable quantities. 

1. Eggs

Cooked eggs are a great source of healthy protein and fat for your cat, Osborne says. Since cats are obligate carnivores, they may even consume eggs in the wild. 

"In the wild felines feed on what's available so consuming raw eggs from time to time is not surprising," says Osborne. However, at home, be sure you're cooking eggs if you're giving them to your cat since raw eggs can contain harmful bacteria such as salmonella and E. coli.

"Offering your kitty small pieces of cooked eggs is a healthy, great treat. Eggs may be scrambled, fried, hard boiled  or even sunny side up," says Osborne. 

It's okay to use a little bit of butter or cooking oil to cook the eggs with, as well, Osborne says.

2. Bananas

Bananas are a safe and healthy fruit that some cats may enjoy as a treat, Osborne says. 

However, be careful with how much you give them since bananas contain a lot of sugar. 

"Excess sugar in felines can lead to a 'sugar high.' Cats may become nervous and agitated and might even bite you as a result. In addition, excessive amounts of sugar can lead to vomiting, diarrhea, and abdominal pain," says Osborne.

3. Strawberries

Strawberries are another fruit that's safe to give your cat as a treat, as long as it's in moderation, due to their sugar content, Osborne says. 

Similar to bananas, you should only offer up a tiny amount to your cat — one half to one teaspoon, without stems and leaves. 

4. Watermelon

Watermelon is not toxic for cats, but there are a few key things to keep in mind, says Anthony Hall, DVM, veterinarian at Northwest Animal Hospital:

• Watermelon contains a lot of simple carbohydrates which can cause your cat's blood sugar to spike, so it should not be given to diabetic cats, says Hall.
• Make sure you're giving your cat pieces of watermelon that don't contain any seeds or rind, which could upset their stomach.

5. Apples

Similar to watermelon, apples are not toxic to cats, but they should only be given sparingly to healthy cats due to their higher sugar content, says Hall. 

Make sure you only feed your cat fresh apples, never feed them canned or frozen because they may contain potentially toxic preservatives. Also, be sure to remove any seeds. 

6. Blueberries

Blueberries are another fruit that aren't toxic, but should only be given to healthy cats in small quantities, says Hall. The blueberries must be fresh, not frozen, to avoid any preservatives.

Blueberries do have antioxidants, but Hall says that there are other better sources of antioxidants for cats, such as regular cat food from reputable brands which will have all the nutrients your cat needs

"If you're looking to just give treats, that's different, but you shouldn't be giving other food to supplement nutrition your cat is already getting in adequate quantities," says Hall.

Foods you should never feed your cat

Here are seven foods you should avoid feeding your cat.

1. Chocolate

Cats should not eat chocolate, because it can contain compounds such as caffeine and theobromine, which may cause increased heart rate, tremors, seizures, and in serious cases, death, says Osborne.

Osborne says dark chocolate and baking chocolate are particularly harmful since they contain more cocoa, which means there's a higher content of caffeine and theobromine which can be potentially toxic to cats.

2. Milk

Despite the stereotype, adult cats should not drink milk. Yes, they consume their mother's milk when they're kittens but that's different from that jug of cow's milk in your fridge.

"For the vast majority of felines, dairy is neither beneficial nor appealing because, in addition to being obligate carnivores, many cats are also lactose intolerant," says Osborne. 

Therefore, consuming milk can cause gastrointestinal issues for your cat like vomiting or diarrhea. 

You can try giving your cat dairy-free milk like almond or oat milk, but you still run the risk of stomach upset, Osborne says.

3. Cheese

Since cheese is a dairy product, it's generally best to avoid giving it to your cats, says Osborne. 

This is for the same reason why they shouldn't drink milk — because they are lactose intolerant. Again, this can cause GI problems like vomiting or diarrhea.

Even dry-aged cheese which might be okay for humans who are lactose intolerant is not ideal for cats, says Osborne.

4. Peanut butter

Peanut butter is best left for dogs to enjoy, Osborne says. This is because the thick consistency of peanut butter makes it hard for cats to swallow, which could lead to choking. Pieces of peanuts in chunky peanut butter also are a choking hazard.

Not to mention, peanut butter may contain ingredients like sodium, sweeteners, and preservatives that can increase your cat's risk of GI distress, obesity, and diabetes.

Individual snacking peanuts, however, are safe to feed your cat as long as they are unsalted and unflavored. 

5. Grapes 

Grapes are toxic to cats, likely due to the tannins, says Hall. This goes for raisins as well since they're just dried up grapes, after all. So, never offer your cat grapes or raisins, even in small amounts.

Hall says grapes and raisins can lead to serious health problems including:

• Vomiting
• Weakness
• Coma
• Seizure
• Kidney failure
• Death

6. Bread

Bread does not contain any toxic ingredients for cats, but they may have trouble digesting it, says Hall. Therefore, you should avoid giving it to your cats, even as a little treat.

"Bread is basically a large fluffy carbohydrate. Cats are not made to digest large amounts of carbs. The yeast in bread can also disrupt your cat's digestive tract," says Hall.

Plus, some ingredients found in certain pre-packaged bread can be dangerous. For example, you may find artificial sweeteners such as xylitol or seasonings like garlic and onion, all of which can be toxic to cats, Hall says.

7. Popcorn

While plain popcorn isn't toxic, it isn't exactly healthy for cats, says Hall. To be on the safe side, you should not feed it to them since popcorn is essentially just carbs and empty calories, and cats have trouble digesting carbs.

Insider's takeaway

When it comes to feeding your cat human food, it's best to err on the side of caution. If you're feeding them one of the foods on this list that is considered safe, make sure you only give it to them in moderation to prevent any adverse effects.