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Pile on healthy pounds with high-calorie cat food

A sleek, svelte cat is a healthy cat, but going too far down the superwaif route can be harmful.

If your cat has shed too much weight, it can have a negative impact on their health—if the weight loss is rapid, it can cause serious damage to your kitty’s organs.

While far more felines suffer from excess pounds, underweight cats are not to be neglected. They need to be fattened up to ensure that their systems continue to function healthily. The best way to do this is through their diet—whether you choose wet, dry, raw, homemade, or tailor-made food, it should be formulated to deliver high calories as efficiently as possible.

Untamed takes a look at the idea of high-calorie cat food for weight gain—what can cause your kitty to be underweight and how to get your feline back to normal size healthily.


The perfect shape for a cat 

Source: Arina Krasnikova

What should you do if your cat is underweight?

Your first step is to determine the cause of the weight loss and address it.

This may involve a trip to the vet, but you should remember that weight loss can have serious consequences in a short time—if your cat hasn’t eaten for 24 hours, you need to take them for a check-up.

Once the issue has been identified—and, hopefully, treated—your vet will most likely recommend a dietary change to put your cat on the road to recovery.

The best way to get your cat back to its correct weight is to introduce a healthy high-calorie diet and stick to it until the correct weight is reached.

The food to help a cat gain weight needs to deliver a large number of calories in as small a volume as possible. Since weight loss is often the result of felines feeling unwell, they may resist large portions of food in one go. Small portions of energy-rich food served often can be the solution.

What is healthy high-calorie cat food?

You want your cat to gain weight, but this should happen in as healthy a way as possible. This means choosing a high-calorie food that is based on what cats have evolved to live off.

Cats are obligate carnivores, meaning that their systems are designed to process:

  • Animal protein
  • Animal fat

Animal protein

Protein is made up of different combinations of amino acids, which are the building blocks for:

  • Muscle
  • Skin
  • Coat

As a carnivore, a cat can metabolise animal protein much better than vegetable sources. This means that your kitty will need smaller amounts of a meat-based diet to get the required nutrients, including essential taurine.

The most digestible forms of protein for a cat are:

Protein source

Digestibility percentage

Chicken or chicken liver


Tuna, prawns, sardines, and salmon


Beef and pork or ham




Wheatgerm, corn, sweetcorn, and other vegetable proteins

Below 65%


Top-quality proteins are what your cat needs! 

Image (c) Untamed

Animal fat

Fat is a viable source of calories for a cat.

Delivering twice as much energy per gram as protein or other food groups, animal fat is the best way to give high calorific content to felines without overloading their systems.

Fat also delivers essential fatty acids to help maintain cell structure and regulate the healing processes in your kitty’s body.

The added advantage of cat food with high-fat content is that cats find the taste and smell irresistible—if your cat’s appetite has been compromised by feeling unwell, high percentages of animal fat in the food can get the juices flowing again.

A diet rich in animal protein and fat will deliver the calories your feline needs to gain weight in the most efficient way possible.

What kinds of high-calorie food are best avoided?

The problem with animal protein and animal fat in cat food is that both are expensive.

Many manufacturers produce cat food for maximum profit, and consequently, you will often see:

  • Low percentages of animal proteins
  • Vegetable instead of animal fats
  • Addition of grains or cereals to bulk the product up

Grains and cereals are carbohydrates, which do not form part of a cat’s natural diet.

What is the best cat food for weight gain?

Untamed is high-calorie goodness in a tin!

Image (c) Untamed

The best you can do for a cat that needs to gain weight is to introduce a diet that is rich in animal protein and animal fat, with a minimal amount of carbohydrates.

You can check what is in cat food by looking at the:

  1. Ingredients list
  2. Guaranteed analysis

Ingredients list

By law, ingredients must be listed in order of their volume in the food.

A good sign is a source of meat sitting at the top of the list, but your investigation shouldn’t stop there.

Many cat foods will list a meat source first, followed by several types of grain or cereal, such as:

  • Wheat gluten
  • Corn meal
  • Ground corn
  • Soybean meal
  • Maize meal

If these were added together, you may find that their volume would outweigh the meat content in the product—meaning that the food is rich in vegetable protein.

Some manufacturers also split single ingredients according to the way they are processed—corn meal and ground corn are good examples of this.

The result is that each individual ingredient makes up a smaller percentage of the whole diet. In total, corn might make up a higher percentage of the product than meat.

A cat diet with a high proportion of grains and cereals may deliver adequate calories, but it won’t do it in the healthiest way for your cat.

Ideally, the ingredients list should consist of:

  • A small number of ingredients
  • Clearly defined products, such as chicken—not the vague “meat and animal derivatives”
  • No artificial additives, flavourings, or preservatives

Guaranteed analysis

The guaranteed analysis ranks each food group in the diet according to its percentage by volume.

The ingredients are split by:

  • Protein
  • Fat
  • Carbs
  • Moisture (the water content of the food in the can or bag)

The optimum values you should look for are:

Nutrient Type

Ideal Percentage

Animal protein

More than 50%


Up to 20%


Maximum 3%

If you need a high-calorie diet to help your kitty gain weight, the fat content can be as high as 25–30%.

If the combination of the ingredients list and the guaranteed analysis tells you that the food is rich in animal protein and animal fat, it is a good choice to help your underweight cat go from skinny back to sleek.

How can Untamed help your underweight cat?

If you need to get your feline’s weight up quickly and healthily, Untamed’s diet plans are the perfect choice.

We are committed to providing the highest quality nutrition for your feline, and all our products are made according to these principles:

  1. Human-grade ingredients
  2. High protein content
  3. Gentle steaming
  4. Vet-formulated recipes

Human-grade ingredients

All Untamed diet options use ingredients that are ethically sourced and fit for human consumption.

High protein and adequate fat content

Untamed cat food has more than twice the level of animal protein that you find in many commercial cat foods. This, combined with optimal levels of fat, means that your cat will get all the required nutrition.

Gentle steaming

Aggressive cooking methods destroy essential nutrients, so our cat food is gently steamed to seal the goodness while removing harmful bacteria.

Vet-formulated recipes

All our recipes have been developed with vets, so each product contains the nutrients your cat needs.

Untamed avoids common allergens in our products, so our offer also includes hypoallergenic foods—even sensitive cats and those with food allergies should find it highly digestible.

Give Untamed a try and see the difference our diets can make!

Try Untamed and get your cat back to its fighting weight!

Untamed wants your feline to be happy, healthy, and haring around your house or neighbourhood.

Feeding cats Untamed is the best way to get weight under control and ensure that they are getting all the nutrients they need in the tastiest of forms.

Our diets are really tasty, as they are enriched with either cat jelly or cat gravy, and you can choose between a variety of great recipes depending on what your kitty loves.

Switching to Untamed for your kitty is an easy process, and you will most likely notice the benefits in no time:


The Untamed effect

Within a week

You should see:

  • Your cat gaining weight to get back to the optimal size and shape
  • More appetite
  • Less mess in the litter tray

In two months

Your kitty should be:

  • Sleeker and more muscular
  • More energetic

After four months

You will notice:

  • A shinier coat
  • Fewer hairballs

For life

Great nutrition should:

  • help your feline maintain weight naturally by balancing calorie intake with more exercise through play

Trying Untamed diets for your cat is easy—here’s what you need to do:

  1. Visit our Try Now page
  2. Tell us more about your cat
  3. Select a meal plan and place your order

Your cat food trial pack will land on your doorstep in no time, and once you have seen how your feline goes wild for our food, your monthly meal packs will be delivered to ensure an uninterrupted supply of goodness.

If you want to make any changes to your standard order, you can customise your cat food subscription from your Untamed account.

You can sit back and watch your feline get happy and healthy!

Untamed—playful kitties guaranteed!

Image (c) Untamed

When does your kitty need cat food for weight gain?

While vets are constantly dealing with cats that are a touch on the plump side, underweight cats are not commonly seen.

Spotting an underweight cat is also not easy and requires you to make a quick examination of the kitty's body. You can tell if a cat is underweight by checking the:

  1. Ribs and pelvis
  2. Spinal column
  3. Skin around the tummy
  4. Weight when picking your cat up

The weight tests you can perform are:

  • If you run your hand over your feline’s ribcage, you should be able to feel a thin layer of fat between the skin and the bones
  • When you feel your cat’s spine, it should be cushioned by a thin layer of fat under the skin
  • The skin around a cat’s stomach should usually be relatively taut—while some felines have a touch of sag, this shouldn’t be exaggerated
  • If a cat feels noticeably lighter when picked up, there may be a problem you need to investigate

If these tests make you suspect your cat may be underweight, you should act quickly to identify the cause of the issue.

What can cause weight loss in cats?

If your cat has recently been on a diet to get rid of a spare tyre, weight loss is a good thing—but you need to make sure the loss isn’t excessive or too fast.

If you haven’t changed your cat’s diet recently and the pounds are still dropping off, there may be an underlying issue to deal with.

Cats lose weight rapidly if they don’t eat enough or gain enough nutrients from the food they consume.

The most common causes of weight loss in cats are:

  1. Gastrointestinal problems
  2. Parasites
  3. Dental issues
  4. Nasal congestion
  5. Overactive thyroid
  6. Diabetes
  7. Renal insufficiency
  8. Cancer

Gastrointestinal problems

If your cat is suffering from a gastric problem, appetite loss can be a knock-on effect. The most common gastrointestinal diseases are:

  • Salmonellosis
  • Listeriosis

In such cases, two things could happen:

  1. Your cat may experience nausea as a symptom
  2. The feline eats normally, but the food passes straight through without delivering sufficient nutrients


Worms or single-cell organisms in your cat’s stomach or intestines can result in nutrients not being metabolised properly. This can lead to gradual weight loss—careful monitoring of your cat is essential to spot this happening before it becomes a serious issue.

Dental issues

Broken teeth, abscesses, or gum disease can make eating uncomfortable for your kitty. Although the instinct to eat is hardwired into a cat, if chewing food causes too much pain, a cat may forego eating.

Nasal congestion

Smell plays a vital role in a cat’s appetite—something as simple as a blocked nose or failing sense of smell can affect cats’ interest in their food. You will notice the effect after a couple of days of them not eating.

Overactive thyroid

Hyperthyroidism is common in older cats and results in the feline’s metabolism being cranked to 11. You may notice that your cat eats considerably more but still loses weight.


Feline diabetes affects older cats and can lead to increased appetite coupled with weight loss. Other symptoms include greater thirst and more frequent urination.

Renal insufficiency

Kidney failure only becomes noticeable in cats once around 75% of the renal function has been lost—by which time the damage is, sadly, irreparable. The most common symptoms are increased water intake and frequent urination, coupled with possible vomiting and diarrhoea.


Cats suffering from any form of cancer are likely to lose weight rapidly. You may also notice them eating more and becoming more lethargic.

If you notice that your cat is losing weight and can spot any of the above symptoms, you should get your kitty to a vet as soon as possible.

A quick trip to the vet can settle your mind 

Source: FatCamera

Is being underweight dangerous for a cat?

While we often rejoice at having lost a few kilos, weight loss in cats can be a serious issue.

As soon as cats’ systems realise that they are not getting enough nutrients from external sources, their bodies will start mobilising fat reserves to generate energy.

This results in the liver being flooded with large amounts of fat, which is stored until it can be metabolised. Fatty deposits rapidly build up around the liver, and this can lead to liver damage—the syndrome is called hepatic lipidosis.

You can reverse the effects of hepatic lipidosis, but only if you:

  • Spot the problem quickly
  • Control your cat’s recovery diet strictly for up to seven weeks

If a cat’s liver function is compromised, this can also affect the:

  • Kidneys
  • Cardiovascular system
  • Pancreas

What if your kitten is underweight?

Kittens not gaining weight is an even more serious concern than underweight adult cats.

Kittens should grow rapidly, doubling in weight every couple of weeks and reaching ten times their birth weight within the first ten weeks of life.

This means that kittens need to consume high amounts of calories every day, as follows:

Kitten weight

How many calories are needed per day

100 g

31 kcal

200 g

52 kcal

300 g

88 kcal

400 g

104 kcal

900 g

162 kcal

1.4 kg

225 kcal

1.8 kg

272 kcal

2.3 kg

327 kcal

2.7 kg

369 kcal

3.2 kg

419 kcal

3.6 kg

457 kcal

4.1 kg

504 kcal

4.5 kg

541 kcal

If their kitten food isn’t delivering the nutrition they need, they are at risk of underdevelopment, potentially compromising their chances of a long and healthy life.

You should check your kitten’s weight progression weekly to make sure that everything is progressing as it should and adjust feeding amounts as necessary.

The more tasty and nutritious your choice of kitten food, the less you will have to worry about weight gain. 

Getting your kitten onto Untamed as soon as they start eating solid food is your best course of action!