Home » Can Hamsters Get Too Fat? [ Healthy vs. Obese Hamster Weight Table]
can hamsters overeat?

Can Hamsters Get Too Fat? [ Healthy vs. Obese Hamster Weight Table]

(Last Updated On: May 28, 2022)

Hamsters are active animals in the wild. As a result, they’re at risk of becoming overweight or obese in captivity, particularly if they eat high-fat foods or lead a sedentary lifestyle.

Hamsters don’t overeat, but they’re selective with the foods they consume.

Many hamsters pick out the fatty seeds and nuts they like best from their food mixes, leaving their scientifically-formulated pellets because they’re not as tasty. So, hamsters can become overweight.

Also, hamsters get fat if they stop exercising. This can be due to several things, such as sickness or injury. Hamsters also slow down when they get old, gaining weight as a result.

Can Hamsters Overeat?

As mentioned, it’s rare for hamsters to overeat as they only eat what they can handle in a 24-hour period, stashing their food and nibbling on it throughout the day and night.

That being said, some hamsters are picky eaters. They eat only the fatty, sugary items from their food mix and leave their healthy pellets alone.

Pellets don’t taste particularly pleasant, which is why many hamsters avoid them. Hamsters will also choose tasty treats over more nutritious foods, filling themselves up on them instead of their pellets.

While this doesn’t typically count as overeating, selective eating has the same effect, resulting in an unhealthy, unbalanced diet that leads to nutritional deficiencies, weight gain, and heart problems.

Is My Hamster Overweight?

If you’ve noticed your hamster has suddenly gained weight or it feels heavier than usual when you pick it up, you’ll be concerned about whether it’s getting too fat.

The best way to check your hamster’s size is to weigh it once a week using kitchen scales. You may need to pop your hamster in a bowl or cup to prevent it from moving about too much. Make a note of your hamster’s weight each week to track any sudden or unexpected changes.

Bear in mind that all hamsters are different, even male and female Syrian hamsters weigh different things. Our hamster weight chart shows the average healthy weights for each species, which you can use as a benchmark when checking your hamster:  

Hamster SpeciesAverage Healthy Weight
Syrian120-200 grams
Roborovski25-30 grams
Chinese30-45 grams
Winter White30-45 grams
Campbell’s30-45 grams

Pet store hamsters tend to be smaller and lighter than ethically-bred hamsters due to the way they’re bred. Similarly, as touched upon, female Syrians are larger and heavier than males.

Don’t be alarmed if your female hamster is at the higher end of the weight scale. Females are larger to survive procreation, so a heavier weight is entirely normal and nothing to be concerned about.

How To Tell If Your Hamster Is Obese

While weighing your hamster is the best way to keep track of your hamster’s weight, there are several ways to tell whether your hamster is obese by the way it looks, feels, and behaves.

Overweight hamsters:

  • Feel heavier than usual
  • Have a noticeable layer of fat around their abdomen
  • Display visible fat rolls on either side when they stand up
  • Find it difficult to move around the cage
  • Become lethargic and inactive, sleeping for longer

Hamsters are only small, meaning their weight gain can be sudden and unexpected.

What Does a Fat Hamster Look Like?

Hamsters shouldn’t look visibly skinny. If their ribs are visible, they’re too thin and need to gain weight. However, fat hamsters will look round, even when standing.

Look at your hamster from above to get the best view of how round it’s become. You may also want to take frequent pictures to give yourself a reference of a healthy weight.

causes of obesity in hamsters

Why Is My Hamster Fat?

It’s normal for a hamster’s weight to fluctuate. However, excessive weight gain is unhealthy.

There are several causes of obesity in hamsters, such as:


Owners commonly overfeed their hamsters. It’s easy to do, particularly if they’re worried about their hamster running out of food.

Hamsters store their food in their cheek pouches, moving it somewhere safe for later. Small Animal Dermatology explains how the cheek pouches extend far down the body and expand like a balloon.

Hamsters can also pack them to capacity due to special retractor muscles. Because hamsters can fill their pouches with so much food, it can appear as if the hamster’s eaten it all overnight.

Syrian hamsters need approximately 1-2 teaspoons of food every 24 hours, while smaller dwarf species need around 1-23 teaspoons over a 48-hour period.

They can also have small amounts of fresh fruits and vegetables every day.

Unhealthy Diet

A study by Experimental Animals found that a diet high in simple carbs and lipids contributes to obesity. However, inflammation contributed to weight gain, leading to more serious health issues.

That’s why hamsters must receive a balanced diet, including fully-formulated pellets – or lab blocks – containing all the nutrients they need to be healthy.

Lack of Exercise

As highly active animals, they need to keep their bodies healthy by running on an exercise wheel, foraging for food, and playing with toys. They also benefit from regular out-of-cage time to run around and roam without too much restriction.

As soon as a hamster stops exercising or reduces the amount it moves, it’ll gain weight at a rapid speed. This is most likely to happen in winter when it gets cold and hamsters sleep longer.

Hamsters stop exercising for several reasons, such as:

  • Sicknesses
  • Injuries
  • Stress
  • Old age

A lack of exercise isn’t only responsible for weight gain – it causes heart disease, diabetes, and stress, which worsens existing health conditions.

What Foods Make Hamsters Fat?

With the exception of scientifically-formulated pellets, hamsters must eat all other foods in moderation to prevent selective eating and weight gain. However, there are food items to be mindful of more than most.

The following foods are most likely to make your hamster fat:

Nuts and Seeds

Most hamsters enjoy the taste of seeds and nuts. They also enjoy biting and cracking into their hard shells for mental stimulation.

This action has the added benefit that it keeps their ever-growing teeth filed down to a comfortable length. While nuts and seeds have their uses, they are high in fat and pose a problem to your hamster’s weight if eaten too often.

The worst culprits include:

  • Cashew nuts
  • Hazelnuts
  • Peanuts
  • Walnuts
  • Almonds
  • Pecans
  • Sunflower seeds
  • Pumpkin seeds
  • Flax
  • Sesame seeds

Restrict feeding your hamster nuts and seeds to once or twice a week, making sure to provide a balanced mix to prevent nutritional deficiencies.

Lean Protein

Contrary to popular belief, hamsters are omnivores. As well as plant-based foods, they require approximately 16% protein in their diets to stay healthy.

Good protein sources include:

  • Hard-boiled eggs
  • Plain cooked chicken (without oils and seasonings)
  • Mealworms and crickets

However, too many high-protein foods will cause your hamster to gain weight. Because hamsters, especially the dwarf species, are so small, they only need tiny amounts of protein to be satisfied and sustained.

Sugary Fruits

Fresh fruits and vegetables are an excellent way to provide hamsters with nutrients they don’t get from their usual food sources. They also provide additional hydration, preventing dehydration.

While fruits and vegetables are fine for hamsters to have every day, sugary fruits like strawberries, mangoes, and bananas, will cause your hamster to gain weight. They’re also responsible for diarrhea – a dangerous condition for hamsters.

You don’t need to cut out these foods completely. Instead, focus on feeding your hamster plenty of greens, such as spinach, cucumber, kale, and broccoli. You should aim for a healthy mix of fruits and vegetables to stave off unwanted health conditions.

Fatty Meats

Even though hamsters can eat a small selection of meat, fish, and seafood, you mustn’t provide your hamster with fatty meats.

Any meat you feed your pet should be devoid of oils, seasonings, and added ingredients to prevent your hamster from consuming unnecessary fat and calories. For example, fried chicken or processed ham is packed with saturated fat, which isn’t healthy for hamsters to eat.


Some owners prefer to feed their hamsters muesli over a pellet or seed mix. Unfortunately, muesli is packed with filler foods that are too high in fat and sugar.

Low-quality muesli doesn’t only cause obesity and diarrhea, but it contributes to poor teeth health. Hamsters are also prone to picking out the bits they like from the mix, resulting in selective eating.

can hamsters die from being overweight?

What Does It Mean When Your Hamster Gets Fat?

If your hamster gets too fat, it likely means a few things:

  • You’re feeding your hamster too much
  • You’re feeding it too many high-fat, sugary foods
  • You need to encourage it to exercise more often

These things are easy to fix with a few minor changes. You must ensure you feed your hamster a pelleted diet, alongside a high-quality seed mix provided slightly less often.

You must also make sure your hamster has access to a large exercise wheel and plenty of toys it can chew and play with to remain active. If your hamster doesn’t lose weight after you’ve made these changes, you should take it to the vet to ensure there are no underlying health issues at play. 

Can Hamsters Die from Being Overweight?

Obesity is a significant problem for hamsters. They have such fragile organs that the additional weight placed on them causes catastrophic injuries and results in irreversible health conditions.

Weight gain kills hamsters because of the following reasons:


Overweight hamsters are more at risk of developing type 2 diabetes than healthy hamsters. It more commonly occurs in the dwarf species, though Syrians can develop it.

Signs of diabetes include:

  • Frequent urination
  • Dehydration
  • Increased thirst
  • Change in appetite
  • Thick, yellow nails
  • Lethargy

The good news is that type 2 diabetes can be controlled with medication prescribed by a vet and a healthy diet. Leave it to get worse, and it’ll eventually kill the hamster.

Heart Problems

Too much fat places excessive strain on the heart, leaving it vulnerable to problems. Many overweight hamsters develop heart failure, causing them to die without warning.

Liver Disease  

A study published by Dove Press discovered that hamsters exposed to a high-fat, high-cholesterol diet are more likely to develop fatty liver disease, as well as mild diabetes. If left untreated, this can lead to more serious problems.

Obesity is more serious in hamsters because of how small and delicate they are. Owners have a responsibility to ensure they feed their hamsters a high-quality diet at the right amounts to prevent avoidable health conditions.