Can hamsters be fat?

how to stop a hamster getting fat

Lockdown weight has been a hot topic of conversation for 2020, because with a pandemic sweeping the nation and a less hectic schedule to keep up, a lot of us have been filling our free time (and faces) with food. But how do you know if your hamster has gained weight? With their adorable chubby cheeks, it can often be difficult to know whether your hamster is overweight or whether they are storing a snack to munch on for later!

How to stop your hamster getting fat: Overfeeding your hamster and not handling them enough can lead to them gaining weight. As long as you feed them a nutritious diet and ensure that they get plenty of exercise then it is unlikely that your hamster will become fat or obese.

It is also important to understand that hamsters, just like other seasonal animals, adapt their feeding patterns and behavior according to the time of year. Therefore, wild hamsters start to grow a thicker coat in winter and tend to only give birth in the spring. Winter White hamsters also tend to adjust their appetite so that they are less hungry when food is difficult to forage for.

Although your pet hamster is unlikely to change their eating habits whilst in your care, you should look out for any signs that your hamster is putting on weight or becoming unhealthy.

How do you know if your hamster is fat or obese?

The easiest way to determine if your hamster is heavier than they should be is to visually examine them. If they feel heavier in your hands and have a slight podge in places other than their cheek pouch, then they may be overweight for their breed.

We probably have the opposite issue with our hamster Oscar, who although loves his food, has always been on the skinnier side and struggles to put on any excess weight.

The average Syrian hamster should roughly weigh an ounce for every inch of their length. Therefore, a healthy adult Syrian hamster will probably weigh between 4 – 6 oz. Unfortunately, this guide cannot be applied to other species of hamster which on average should weigh:

  • Robovorski – around 1oz
  • Campbell Dwarf and a Winter White – between 1-1.5oz.
  • Chinese hamster – anything from 1.5 – 1.8 oz

If you are unsure of exactly how much your hamster weighs and are concerned about their health, then you can weight them on a pair of scales. The scale itself needs to be designed for items like food or post as it needs to be able to read weights as low as 1oz.

In order to ensure that your hamster stays calm and still while being weighed, it is best to place them inside a container (taking the weight of this off the total weight at the end) and adding a couple of treats for them to sit and enjoy.

Signs and symptoms of hamster obesity

In addition to obvious visual weight gain, another sign that your hamster is obese could be lethargy and an uninterest in exercise.

You should be aware of these signs and symptoms as if left untreated, hamster obesity can lead to other illnesses including diabetes, heart problems and an overall shortened life expectancy.

What causes hamsters to become obese?

In their natural environment, in order to survive, a hamster would run for more than a mile a night in search of food, shelter or a mate.

If, however, a hamsters natural habitat is a small, enclosed cage rather than a vast expanse of desert, then it is likely that they will become complacent. With nowhere to run and with food served up daily in a dish there is no motivation for your hamster to exercise.

A lack of regular movement can result in weight gain for your hamster, especially if they are supplemented with lots of tasty treats to eat.

Certain foods in the mix of your hamster’s pre-packaged muesli may look healthy and nutritious, but can actually be fattening for hamster’s just like they are for humans.

A scientific study that was carried out in 2017, concluded that hamsters that are fed a high amount of simple carbohydrates with lipids (fats) are likely to become overweight. Generally, your hamster should only consume approximately 4-7 percent of fat, unless they are pregnant. Therefore, if your hamster is being fed a poor diet, that lacks any fresh fruit and vegetables then there is a chance that they could become obese.

Fat exacerbates the probability of developing hamster diabetes and as certain types of hamsters are prone to this disease it is important that we monitor their intake carefully.

Just like humans, your hamster’s weight also tends to fluctuate depending on the seasons. When the nights start to draw in and there are fewer daylight hours, hamsters commonly gain weight. This is due to an increase of melatonin and is a natural result of your hamster “preparing” for winter. The opposite happens when summer returns, as hamsters tend to undereat allowing their weight to return to normal.

Finally, if you do notice that your female hamster is gaining weight around their middle, then you should check that you are not confusing their weight gain for being pregnant. If your female hamster gets plenty of exercise and has a healthy diet, then check with your vet that this sudden weight gain is not caused by the arrival of impending pups.

How to treat a fat hamster

Prevention is always better than cure, so the best thing to do is to instil healthy eating habits with your hamster from the start.

If it is too late for this and your hamster is starting to become on the chubbier side, then you may need to replace the fatty snacks with plenty of fresh green. If your hamster is obese then you may need to place them on a low-fat diet for a short while, but please only do so having consulted with your vet.

Another great way to keep your hamster fit and healthy is to ensure that it has a large supply of toys and exercise options. This could be a hamster wheel, maze of tubes, climbing frame or even a homemade tunnel. Regular handling also helps to keep your hamster fit and healthy and provides a welcome change of scene to their everyday cage.


Most hamsters do not eat to excess and love to exercise – especially at night. Therefore making sure your hamster has a good diet to fuel their nighttime antics should stop them from becoming obese. If you are concerned with the health of your hamster then you should get them seen by a vet.


We started this website to share our experiences with owning and looking after hamsters. Read our blog for tips and advice to help make your hamster happy.

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