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Can Fish Eat Bread? Is It Good or Bad for Them? Health & Safety Facts

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By Lindsey Stanton


When you have fish, you might be tempted to feed them a bunch of tasty treats. After all, they’re our pets and we want to treat them right. Something you may have seen people feeding their fish is bread.

That said, can fish eat bread? Is it healthy for them? While fish will eat bread if you feed it to them, it’s definitely not healthy for them since bread contains yeast and gluten, which fish cannot digest. This can lead to several health problems, including constipation, swelling, and bloating.

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Do Fish Actually Eat Bread?

Technically speaking, yes, your fish will eat bread if you feed it to them. There’s no doubt about the fact that they do seem to enjoy it as a treat. However, this does not mean that it is healthy for them.

If we look at this objectively, it’s not like bread is much good for humans either, particularly white bread that is loaded with sugar, carbs, and so much more.

It’s like dogs and chocolate. Sure, every dog will eat chocolate, but it certainly is not healthy for them in the least, and this is the same when it comes to bread and fish.

Is Bread Good or Bad for Fish?

The fact of the matter is that bread is bad for fish, very much so. Under no circumstances should you be feeding your fish bread, and this is true for many reasons. It will make them sick and it can lead to some really serious health concerns, even death. So, what is in bread that it so bad for fish and why does it make them sick?

Yeast, Gluten, & More

The reason why bread is so bad for fish is that it contains yeast, gluten, and carbs too. Each of these substances is not good for fish and can make them very ill. These are all substances that fish cannot digest properly, and this will result in extreme sickness.

feeding fish
Image Credit: Pixel-Shot, Shutterstock

Reasons Not to Feed Your Fish Bread

There are a variety of health consequences that your fish will have to suffer if you feed bread to them. Let’s take a closer look.


One of the main things that is going to happen when you feed bread to your fish is constipation. Bread contains a lot of gluten, and this is something which fish simply cannot digest.

Even many humans have problems digesting gluten. When fish cannot digest something like gluten, it will cause blockages in the large intestine. These blockages make fish feel sluggish, unhealthy, and ill, and eventually, these blockages lead to even more serious health concerns.

Swelling & Bloating

The next health concern that you need to consider when it comes to feeding fish bread is swelling of the stomach and bloating. The swelling of the stomach is caused by the yeast in bread. Mostly all bread contains yeast because this is the substance which makes it rise and become fluffy.

Fish cannot digest yeast, and moreover, yeast will swell inside of a fish’s stomach, which then in turn causes the stomach to swell. This can be extremely painful for fish and in extreme cases it may even cause the stomach to rupture, thus causing death.

At the very least, the swelling caused by the yeast, combined with the inability to digest gluten, will result in extreme bloating and gas. Bloating will make fish lazy; they won’t want to swim around, and they won’t want to eat either. If your fish is not eating, then you have a serious problem on your hands.

bloated dropsy goldfish
Image Credit: Wari_Nuchczy, Shutterstock

Lower Metabolism

Yet another serious health effect that will take place if you feed your fish bread is that their metabolism will be lowered. Because the fish are constipated, swelled up, and gassy, they won’t want to eat, and they won’t want to move around either. They will stop swimming for the most part.

When a fish’s metabolism slows down too much, it will cause them to stop digesting food properly, even less so than was caused by the yeast and gluten.

In layman’s terms, they’ll stop eating, and combined with a lower metabolic rate, it means that fish won’t be able to process the nutrients they need to stay alive. This can lead to serious calorie and nutrient deficits, which then leads to malnourishment and a whole host of other issues.


One of the most serious health consequences that your fish will have to deal with if you make the unfortunate decision to feed them bread is poisoning. When your fish gets constipated, it means that it cannot pass waste through its system. This waste builds up over time, and yes, fecal matter is poisonous.

This buildup of what is essentially poison will make your fish feel sluggish and ill. Eventually, the level of toxicity in your fish will reach the point where the fish will die.

sick fish
Image Credit: Andrii Oleksiienko, Shutterstock

Bread & Aquarium Water Quality

There is another big reason why you should not feed bread to your fish and it has to do with the quality of the water. Sure, the fish will eat most of the bread, but some of it is going to remain in the tank. That remaining bread will get into small crevices and it can clog the filter too.

The bread itself will start releasing ammonia as it decomposes, and if the filter is clogged, it won’t be able to keep the water clean. In turn, this low water quality and the buildup of ammonia, along with other substances, will lead to extreme water toxicity which can quickly kill fish in a matter of days.

What Do Fish Eat in the Wild?

In the wild, fish eat a variety of foods, but none of them contain yeast, gluten, or large amounts of carbs. Wild fish require some amount of protein to keep their muscles strong and their bodily functions running. They also need a bit of fat to insulate their bodies and minute quantities of carbs to provide them with energy. They even need a little bit of vitamins and some minerals too.

In the wild, fish eat things like insects and insect larvae, small crustaceans, other fish, plant matter, and sometimes algae too—none of which contain yeast or gluten.

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What Other Human Foods Are Bad for Fish?

Besides bread, there are some other foods that you should avoid feeding your fish at all costs. The following is a list of foods that you need to avoid feeding your fish and why this is the case.

Carb Rich Foods

Fish only need a minute amount of carbohydrates to provide them with energy. However, too many carbs will result in gas and bloating, which is uncomfortable and painful and can lead to your fish not eating, a lower metabolic rate, and eventually death.

Any carb-rich foods like bread, pasta, and sugars need to be avoided. For those of you who don’t know, sugar is a type of carbohydrate, so no feeding your fish any sugar-rich foods like chocolate or gummy worms.

cacao beans on chocolate bars
Image Credit: Tetiana Bykovets, Unsplash

Fatty Meat

Meat in general is not great for fish, especially fatty meat, by which we mean chicken and poultry, waterfowl, pork, and beef. These meats contain a ton of fat, and this is not good for fish. Fish only require very small amounts of fat to provide them with some insulation.

If a fish has too much fat in its diet, it can cause a myriad of health concerns, with obesity being just one of them. Too much fat in a fish’s diet can also lead to liver problems, and these can be fatal when left unchecked for too long.

One of the only acceptable meats to feed your fish is beef heart, as it has nearly no fat in it.


Fruits are another big one that you need to avoid feeding your fish. Fruits contain a ton of carbs and sugars, and none of those are good for fish. As covered in detail now, excessive carb intake can lead to some really serious problems.

Moreover, fruits don’t even contain the right nutrients that fish need to be healthy and to survive. Even a single bite of fruit can cause numerous serious stomach and digestive issues, which, at the least, are uncomfortable, and, at worst, can cause death.

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Image Credit: Obodai26, Pixabay

Anything with Yeast

As talked about above, yeast causes swelling and bloating in fish, very serious and life-threatening issues, so never feed your fish any food that contains yeast.

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What Can You Feed Fish in a Pond That’s Good for Them?

Of course, just like there are foods that are bad for fish and should be avoided at all costs, there are also foods that are good for fish.

Here is a list of the best foods to feed fish in a pond, stuff that’s actually good for them:

Fish Pellets & Flakes

The best thing to feed fish in a pond is good old fish food. Exactly what type of fish food you feed them, whether pellets or flakes, will depend on the specific type of fish. However, either way, fish food is specially designed to meet the dietary needs of fish, and therefore, it’s the number one choice to go with.

Freeze-Dried Foods

Fish do appreciate some meaty snacks. Things like freeze-dried blood worms, daphnia, brine shrimp, and other such freeze-dried foods are perfect. They are high in proteins and other nutrients while containing no gluten or yeast, they’re low in carbs, and they taste great too.

The advantage of freeze-dried foods is that the freeze-drying process kills off various parasites and bacteria which may be harmful to fish.

Beware that some fish need way more protein than others, so you do need to ensure that you don’t give them too much or too little meat.

red bloodworms in a pile
Image Credit: schankz, Shutterstock

Live Foods

You may also opt to feed your pond fish live foods, such as small feeder fish, crustaceans, and live insects. This is more or less the same as freeze-dried foods, but of course, these are still live.

Live foods may contain parasites that may be harmful to fish, so some people avoid these. However, many fish do like to hunt for live foods, as they are natural predators.


Simply boil some peas and peel the outer shell off of them. Peas contain a ton of nutrients that are healthy for fish, and they don’t contain any of the bad stuff either. Feeding your fish boiled and peeled peas is a great way to relieve constipation.

Credit: Ajay_Photography, Pixabay

Leafy Greens

Leafy greens contain a ton of fiber, iron, and other nutrients that your fish can use. All you have to do is chop the leaves into small pieces, boil them for a few minutes, and they are good to go.


Zucchini is a great veggie to feed your fish as it does not contain any substances that fish cannot tolerate. Moreover, these green veggies also contain lots of protein, antioxidants, and fiber too, all of which are great for your fish.

Peel the zucchini, boil it, chop it into small chunks, and it’s good to go.


Image Credit: ❤ Monika Schröder ❤, Pixabay

Cucumber may not be the most nutrient-rich food, but it does not contain anything bad for fish, it’s low in calories and does have a good deal of fiber.

Just like with zucchini, peel, boil, and then chop the cucumber into small chunks.

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The bottom line is that bread, as well as anything else that contains yeast or gluten, are all bad for your fish.

We’ve explained why not to feed bread to your fish, and we have provided you with many alternative foods that are great for fish, so stick to them!

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