How to Fatten Up a Cat

If your beloved feline is little more than fur and bones, we have some tips on how to fatten up a cat. There are several causes of weight loss in cats, some of them medical, some environmental, and some that have to do with a cat’s finicky taste. Before figuring out a weight gain strategy for your cat, it’s important to narrow down the list of potential causes for your cat’s weight loss.

Medical Conditions

As cats age, they tend to develop medical conditions similar to humans. Some of these conditions are known to cause weight loss, and include hyperthyroidism, diabetes, parasites, and cancer.

  • Hyperthyroidism
    As cats age, they are prone to developing hyperthyroidism, a condition where the thyroid produces too much thyroxine - a hormone. This speeds up the cat’s metabolism, causing it to burn more calories than it takes in.
  • Diabetes
    This medical condition has become widespread in cats and is almost entirely due to grain-based kibble cat food.
  • Anorexia
    Strange as it may sound, cats can become anorexic. If your cat refuses to eat for more than a day or so, it can be due to several factors, including a medical condition, anxiety and stress, and even psychological disorders. If you think your cat may be anorexic, have him examined by a vet.
  • Fatty Liver Disease
    Medically known as hepatic lipidosis, this condition is characterized by the infiltration of fat into the liver. The most common causes of fatty liver disease are sudden change in diet (i.e., changing cat food without gradually introducing it) and stress triggered by environmental changes. If you observe your cat not eating and behaving strangely, have her examined by a veterinarian.
  • Food Allergies
    Cat food contains ingredients that aren’t part of a cat’s natural diet. Cats can develop allergies to these ingredients, which may affect the amount of food they eat.
  • Food Intolerance
    Cats can develop intolerance to food just like humans can. If your cat stops eating or begins vomiting frequently, have her examined for food intolerance, then change her food accordingly.
  • Parasites
    Cats who spend time outdoors are the most likely to be infected with parasites. If your cat is quickly losing weight, look in the litter box and examine his stool. If your cat is infected, you will see worms. This is easily treated with deworming medicine.
  • Decreased Sense of Smell
    A cat’s hunger is triggered by their nose. Anything that impairs their sense of smell will have a direct impact on their appetite. Aging, respiratory infection, and nasal blockage are the main causes for impaired smell in cats.
  • Dental Disease
    This can take the form of periodontal (gum) disease, oral cancer, feline stomatitis (an autoimmune disorder that causes painful swelling of the mouth, throat, and pharynx), or tooth resorption. Left untreated, these conditions often lead to your cat not eating.
  • Cancer
    In cats, the development of cancer is often associated with feline leukemia. It can be difficult to detect cancer in cats, since they don’t communicate pain or discomfort. A routine check of your cat’s body for unusual bumps and lumps can help you detect cancer early, making it easier to treat and much less costly.

Environmental Stressors

Most cats do not like change. Something as simple as moving their food and water bowls can trigger symptoms of stress and anxiety. Newborn babies, new pets, and even new people in your home are also stressors that can kind of freak your cat out, causing it to quit eating, hide in unusual places, or develop odd behaviors.

Being aware of this when making changes can help your kitty adjust more quickly to new circumstances.

Psychological Disorders

As your cat ages, it may develop psychological disorders which affect its appetite. Many of these disorders can be treated, helping to restore your cat’s well-being. If your cat begins exhibiting unusual or bizarre behavior, have it examined for mental illness.


As cats get older, they often lose weight. Sometimes, this is due, in part, to medical conditions, stress, or psychological disorder. However, some cats continue to lose weight even after specific causes have been treated. Healthy cats also tend to lose weight, although why that is still remains a mystery.

A Weight Gain Diet for Your Cat

Get ready - your skinny cat is about to pack on the pounds. This weight gain strategy will work for most cats. As with any diet, you need to observe how your cat is adjusting to it, and if the strategy is working. Weigh your cat once a week and change or tweak this strategy for optimal results.

Determine Proper Target Weight

Your cat’s target weight should be based on its breed and overall size. For example, if you have a Blue Russian, the weight range is 8-15lbs. Start with the minimum weight as your target weight and develop your weight gain feeding strategy accordingly.

Feeding Strategy

The feeding strategy is made up of three components: food type, feeding frequency, and portion size.

Food Type
  • Kitten food is often recommended to help your cat gain weight because it is higher in calories than adult cat food. Whether you choose to use kitten food is up to you. Many cat owners report success just by supplementing their cat’s current diet with other adult cat foods.
  • Canned cat wet food is recommended as the main part of your cat’s weight gain diet.
  • Kibble cat food can be used as a supplement to your cat’s canned food.

Some of you may be feeding your cat a primary diet of kibble, and that’s ok. Include the wet food as the supplement and proceed. Most cats love wet food, so it should be easy to introduce it into their diet!

Feeding Frequency

If you’re feeding your cat twice a day, change it to 4-6 times a day, but with smaller portions at each feeding. This is the key to your cat’s weight gain. The basic approach is to determine a full day’s food for your cat’s target weight, then divide it by the number of portions you plan to serve your cat.

Cats are picky, so they may not like their food to sit out all day, which is why feeding them more often in smaller portions works wonders!​ A good way to do this is with an automatic cat feeder.

Portion Control

With the target weight of your cat in mind, look at the feeding instructions for your cat’s food. Total the recommended amount for the day and divide that into the number of feedings you have planned. For example, if your cat gets a half-can in the morning and a half-can in the evening, then take the whole can and split it into four portions to be fed throughout the day.

If you’re using a combination of both dry and wet cat food, look at the daily feeding for both, and divide accordingly. The main thing is that you want to feed your cat the right amount of food, not too much. Be sure to evenly spread the feedings out over the course of the day.


Before you go buy extra cat food to help your cat gain weight, it is important to first determine if there aren’t medical conditions or other factors causing your cat’s weight loss. Once those conditions are diagnosed and treated, you can safely begin implementing the weight gain feeding strategy.

If your cat is healthy, then it’s safe to introduce the changes you need to make to help your kitty regain its weight. When making any change to your cat’s diet, be sure to implement it gradually and monitor your cat’s behavior closely. To check progress, weigh your cat once a week and make changes to the strategy as needed to help your cat regain its ideal weight. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking from “Cat Cat Cat” to Amazon (, or,,, or

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