Why Is My Hamster Fat All of a Sudden?

Taking care of a pet not only gives a person a sense of responsibility but the satisfaction brought when the pet is healthy and gives the person all its love and emotional support. The relationship benefits both ways: pets get someone to take care of them, while humans get the companionship they crave for.

Pets contribute to our overall health. 74% of pet owners, as per HABRI, a research organization based in Washington, DC, claim that having a pet has benefited their psychological health. According to studies, interactions between humans and animals raise oxytocin levels within the brain, bringing about feelings of warmth, focus, and serenity.

One such common category of pets is rodents, especially hamsters. The little packets of energy are well-loved among most people in the states.

Since they are low-risk pets, hamsters are a preferred option for most Americans. However, the adorable tiny fur balls are not immune to many ailments, and part of their behavior resembles that of the human anatomy.

Even though most pet owners like feeding and spoiling their furry companions, obesity and unhealthful weight growth can seriously impair a hamster’s quality of life and overall likelihood of survival.

Even though a chubby, overweight hamster may appear cheerful and cuddly to you at times, it may suffer from poor movement and tardiness due to its excessive weight gain.

Therefore, if you have overfed your pet hamster, you must take all the necessary steps to assist your pet in losing extra weight. However, if you haven’t fed it a lot and it still gains weight, it could be an underlying issue.

Why Is My Hamster Fat All of a Sudden?

Your hamster may suddenly gain weight due to overeating, laziness, hormonal changes, aging, pregnancies, psychological stress, a diet deficient in vitamins, iron, and minerals, or a disease like constipation.

A hamster can easily complete its tasks pleasantly if it is intelligent and energetic. When it gains weight, it adopts a sedentary way of life.

You must handle this issue carefully for the hamster’s health to prevent weight gain and ensure that it leads an active, healthy life.

By reading on, learn more about what you can do to assist your pet hamster’s return to health and overall fitness.

Read: Can Hamsters Get Hurt from Falling?

An Excessive Appetite

The most basic requirement for life is food. It is necessary to carry out everyday tasks since it provides the hamster’s body energy and power.

If your pet eats more food, especially food that is high in fat, your hamster will get obese. As a result of overeating, fat begins to build up in the body. When it first begins to accumulate, this fat is not noticeable; however, after a few days, it is pretty evident. The hamsters initially form cheek pockets and then begin storing in them. This is quite unhygienic as well.

They become obese from eating too much. So refrain from feeding your hamster harmful, high-fat foods. Never provide more than the recommended amount; always follow the instructions.

Hormonal Imbalance

Similar to humans, hamsters experience hormonal fluctuations. The hamster may gain weight as a result of these alterations. Being overweight might result from hormonal imbalance.

The issue is prevalent in females,although it is also possible to occur in male hamsters; however, it is less frequent thanin female hamsters.

In female rodents, the hormonal balance alters during the ovarian cycle and the gestation phase. If these modifications are improper, they may result in fat, particularly abdominal obesity.

In the lower portion of the stomach, fat begins to accumulate. This is the same situation women face when they have irregular period cycles.

Since you can’t do anything to fix this issue, you must take your hamster to the doctor for the proper care to handle this condition. Or elsethe hamsterwill keep putting on weight and start to appear obese.

Seasonal Variations

The bodyweight of hamsters is significantly influenced by the seasons. Since there are several food types with varying nutritional values accessible depending on the season, the weight automatically fluctuates at different times of the year. Seasonal variations in physical activity are also a direct result of how hamsters like to live atother times of the year. 

The hamster can be active all over and enjoy it in the heat.However, hamsters’ physical activity decreases in the winter and they can consume foods high in carbs. The hamster feels cold, so it consumes hot food to stay warm and sits in a corner while putting up its little duvet. Due to the snow, it prefers to stay put and is content to hunker down in a corner.

Moreover, hamsters, such as the Syrian breed, can consume spiders, which may cause them to gain weight.

The hamster’s weight increases, and it appears chubby throughout the winter because of these factors. In contrast, sweating aids in calorie burning during the summer, but when it’s cold outside, the body begins to store fat instead of sweating. You unexpectedly realize that the pet hamster gained significant weight after or throughout the winter.

Low Iron In The Body

A healthy iron intake is crucial because it gives the hamster vigor and energy while promoting its physical health. Your hamster can be safeguarded from several illnesses by getting enough iron. A deficiency of iron will lead to fat accumulationin your hamster’s body.

The liver’s dysfunction is the primary cause of the iron shortage. The weight gain signifies that the liver is overworked and is unable to carry out all of its activities properly. The body must therefore deal with an iron deficit as a result.

Start feeding your hamster iron-rich foods as soon as you realize it is iron deficient so it won’t lead to fat deposition.


Mental stress, which might be due to fights with other pets or the loss of parents or a previous owner, can be lethal for hamsters.Stress decreases physical activity, therefore, slows down the body’s metabolism.

Neurons are severely harmed by mental stress, which prevents them from properly communicating with the rest of the body. You note that your hamster can gain weight due to the increased rate at which fat cells begin to grow.

You must take excellent care of your pet and maintain it with deep affection, concern, and concentration if you want to protect them from this scenario.

Once the hamster is comfortable around you, it may therefore forget about any of the misfortunes mentioned above and begin living the good life comfortably. This will also help if the hamster is facing sleep apnea.

Explore: Can Hamsters Have a Heart Attack?


If you have a female hamster, she could be very well pregnant. The mother hamster appears to be healthy and plump since her weight is included in that of the baby hamster.

Due to hormonal imbalance, the female hamster retains her weight during and after delivery. The female hamster never gets permanently overweight during pregnancy. However, if she gets sluggish and stops participating in healthy activities, the difference in looks could make her look fluffy for a long time.

Old Age

The last reason could be the aging of your hamster. Physical exercise is also quite low as hamsters age, which makes it difficult for meals to be effectively digested. As a result, during this age, gaining weight is more likely. Old age causes the skin to separate from the bones, which causes fat to accumulate in that space, making your hamster overweight.

How To Make My Hamster Lose Weight?

In order to assist your furry friend hamster in losing weight and becoming healthy once more, you must make the essential changes in its lifestyle. Thankfully, there are several methods to assist an overweight hamster in losing weight, a few of which are given below:

Before doing anything else, you should change and adjust the daily diet of your pet hamster. Oily nuts and seeds may make your rodent companion very happy, but they should not be consumed daily.

Replace your hamster’s diet’s portion of nuts and seeds with fresh vegetables and fruits instead, and only use the nuts and seeds as treats occasionally.Even though this shift may initially frighten your hamster, it will understand and grow accustomed to the low-calorie way of life.

Secondly, it’s crucial to give the mouse high-quality pet food that’s also suitable for its age and introduce it to newer and more nutritious foods.

Thirdly, just like humans, ill-timed munching can lead to fat accumulation; the same phenomenon applies to hamsters. So, it’s crucial to limit your hamster’s eating time and make it at suitable times of the day in addition to making the necessary food modifications.

In addition, if you want to see your hamster healthy again, physical activity is also necessary. So give the hamster some time to move around on its wheel and spin about your home in a hamster ball. Even while filling the food bowl at the hamster’s feeding time, be sure only tofill a calculated and recommended amount and abstain from overfilling it.

Final Thoughts

Some people find enormous joy and contentment in caring for their small pet hamsters, even though caring for another human can be quite soothing in many ways.

However, sometimes the love is misunderstood, and the hamster is overfed, which can be very harmful to it. Furthermore, there could be some other issues like pregnancy or stress or a deficiency due to which an abnormal amount of weight is gained.

So, if your pet hamster is getting fatter and lazier, it’s time to switch out all the fatty nuts and seeds for fresh fruits and vegetables in its diet.

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