Do Cat Diets Really Work? | Catzio

Do Cat Diets Really Work?

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  1. 5 Pillars of a Balanced Diet for Cats
  2. Cat Diet Plan for Weight Loss
  3. The Efficacy of Grain-Free Diets for Cats
The cat food market is overrun with all different kinds of diet formulas, resolving conditions from weight loss to dry, itchy skin. Instead of trying them all one-by-one, it's best to determine which will produce real results for your cat before committing to the change. 

Does diet cat food work? The effectiveness of any food depends on the type of diet you’re feeding. For example, weight loss plans have been proven to help cats shed over 11 pounds over six months. On the other hand, grain-free diets are not yet supported by concrete evidence. Any advantages are likely attributed to individual ingredients. 


A small grey adult cat licking its lips as its caretaker pours dry cat food onto a plate.


To determine which feeding routine is best for your cat, you must first develop a foundational knowledge of the general house cat diet and work from there. You can then do further research (and consult with your veterinarian) to determine which of the alternatives discussed here could be suitable for your kitty. 

5 Pillars of a Balanced Diet for Cats

Not all cat diets are formulated with a specific goal, such as losing weight or relieving digestive or other health issues. Some are designed with the kitty's day-to-day needs in mind, with the sole priority of maintaining the cat's excellent health.

Regardless of your cat's current physical or medical condition, there are a handful of dietary guidelines you should adhere to for a happy, healthy life. Just like humans, kitties need specific foods to keep their bodies operating as normal, support a healthy immune system, and defend against preventable, diet-related diseases such as pancreatitis, urinary tract diseases (UTIs), and heart disease. 

Veterinarian-recommended foods and their associated daily intake levels provide minerals, vitamins, proteins, and other nutrients that are vital to your cat's wellbeing. These and other pillars of a general cat diet plan are below. 

1. Feed an average of 200 calories daily 

Of course, this will vary based on their age, weight, activity levels, and more. Generally, the total energy your cat gets from its daily nutrient intake should adhere to these guidelines: 

  • Protein: 52% 
  • Fat: 36% 
  • Carbohydrates: 12% 

Ask your vet how much is suitable for daily feeding and pay close attention to the specific calorie counts on each food product you buy.

2. Limit treats and snacks 

Treats and snacks should only comprise only 5-10% of your cat's total daily calories 

You are welcome to offer your kitty the occasional piece of cooked tuna, fish, chicken, liver, or cheese in moderation. Catnip is also a wonderful snack from time to time. 

3. Your cat needs to eat meat 

Cats evolved as “obligate carnivores,” meaning they need foods that are mostly or exclusively composed of animal protein (e.g., meat, organs, etc.). 

This means that your cat cannot live on vegetarian or vegan diet plans. Sure, if you hand your kitty a piece of celery, it may gnaw on it a bit, maybe even swallow the vegetable. However, having it eat an entirely plant-based meal will essentially starve your kitty of crucial nutrients, inevitably resulting in poor health. 

In fact, a recent Q&A with Dr. Martina Cecchetti, wildlife and animal companion ecologist, revealed that meat is more important to your cat’s diet than you may realize. 

“[C]ats may hunt more because they are stimulated to address some deficiency in their provisioned food, probably something small such as a micronutrient, which is fulfilled by a meaty diet.” 

Dr. Martina Cecchetti, Wildlife and Animal Companion Ecologist, University of Exeter 


The researcher was able to draw this conclusion from a 12-week trial involving 355 cats. When the cats were fed a high-meat protein diet, the number of animals they killed fell by a whopping 36%. That said, not only is a suitable diet crucial to your cat’s physical health, but its behavior as well. 

A photo of a casually lounging on a sofa, waiting for its dry or wet food.

4. (Optional) Feed a commercial kibble diet 

Although many people think commercial kibble is less desirable than natural alternatives like raw meat, feeding dry food can be among the best food options for your cat. Many pet food manufacturers carefully design kibble with veterinary guidance  to fulfill all your cat's core nutritional needs with a bonus of tasty flavor. 

Dr. Julie A. Churchill, DVM suggests that cat owners pay more attention to the formula's concentration of nutrients than anything else, although individual ingredients are important, too. Specifically, you should look for the percentages of proteins and fats. 

Additionally, look for an Association of American Feed Control Officials (AAFCO) on the packaging to confirm that these nutrients, in addition to carbs and grains, are balanced. 

5. (Optional) Chat with your veterinarian about homemade alternatives

If kibble doesn’t float your boat, chat with your vet about a potential homemade diet plan. The guidelines below will help you develop a well-balanced meal: 

  • Crude protein: This constitutes meat, fish, and other animal-derived products. Your cat should get 10-12.5 g of this every day, making up 40-60% of your cat's daily diet. 
  • Fat: The best fats for cats are animal fats or plant seed oils. Ideally, these should amount to 4-5.5 g of the daily feeding routine, making up  30-50% of your cat’s daily caloric intake. 
  • Carbohydrates: Healthy carbs for your cat usually include cooked grains, potatoes, legumes, and similar foods. Relative to protein and fat, this should comprise less than 15% of your cat's daily consumption. 

This is a general look at how you should be feeding your cat each day. Cat diets modeled after these suggestions help maintain the best possible health for your pet and do wonders to prevent the onset of certain illnesses and physical ailments like unhealthy skin and fur.

Now, suppose your cat develops a health problem. In that case, you can tweak a few elements of this general diet structure to restore and sustain their wellbeing.

A veterinarian weighs a siamese cat to verify its healthy weight.

Cat Diet Plan for Weight Loss

One of the most common health problems to plague house cats is obesity. As much as we love our kitties, sometimes we humans can be detrimental to their health. 

Out of enthusiasm for their pets, some cat owners shower their feline companions with treats. At times, these tasty snacks are so plentiful that the cat puts on one too many pounds before the owner catches on. 

Because of such mishaps, some of the most sought-after cat diets are those formulated for weight loss. Still, as popular as these are, do they really work? Scientific research says, "Yes!" 

83% of cats trim down on weight loss diets, scientists say 

In a 2016 study involving 132 obese or overweight kitties, scientists illustrated that feeding a "weight management" food plan for approximately six months resulted in 83% of the patients losing a significant amount of weight. The average weight loss rate was around 11 lbs (slightly less than 3% of the original body weight) throughout the trial period. 

Interestingly, 79% of the cats consumed more calories from the specially formulated weight loss food than recommended, yet still had success in shedding a few pounds. This means that, even if you mistakenly overfeed your kitty throughout their dieting phase, you can still rest assured that everything will turn out just fine. 

The ideal cat weight loss diet 

A typical weight loss diet for cats is characterized by the following traits:

Set your cat’s target weight. Your veterinarian may initially suggest aiming for a weight that isn't quite their ideal weight. This will make the transition much easier for you and your kitty. You should meet at least 80% of a cat's RER (resting energy requirement, which is the amount of energy they need to maintain their body at rest). See the examples below:

  • An 8-lb cat needs about 180 calories (kcal) per day.
  • A 10-lb cat should eat 210 kcal per day. 
  • A 12-lb cat can eat up to 230 kcal daily. 

A cat happily looks up at the camera, standing over its dual bowl containing dry food on one side and water on the other.

Get a special weight loss formula. Replace your cat's regular kibble with specially formulated weight-loss food (this information should be printed on the pet food label).

Most weight loss cat foods you'll find in stores are designed to eliminate only a small amount of weight. If your kitty needs to lose more than just a few pounds, you should consult with your veterinarian. 

They'll likely suggest foods like Hills® Prescription Diet Metabolic, which not only helps shed those extra pounds but increases your cat's metabolism as well. This and similar brands are widely accepted as the best diet foods for cats.

Stop free-feeding. If you usually free-feed your kitty, switch to designated meal times throughout the day. Experts suggest offering your cat canned food multiple times each day to quell any reservations of potentially picky kitties. 

Take things slowly. Give your cat 2-3 weeks to acclimate to the new feeding routine. Lead a gentle transition by providing the new, specialized food in a separate bowl. Over time, progress to the new diet by mixing the weight loss food into its normal food. 

Add the new food into the present diet in quarters. (This means you must offer one part weight loss food, three parts current diet, then two parts weight loss food with two parts current diet, then so on.). In the final week, replace their regular food entirely. 

Please check with your veterinarian before committing to a weight loss diet. Mistakes like over- or underfeeding can lead to serious medical consequences like fatty liver syndrome, leaving your cat much worse off than they started. So, it’s best to get expert guidance before changing up your feeding routine. 

A cat licks a sushi roll sitting in a container full of human foods.


The Efficacy of Grain-Free Diets for Cats 

Grain-free diets are among the most common meal plans chosen for cats. Although this can help reduce the number of carbs present in their daily meals, veterinarians say that the term "grain-free" is more marketing- than health-related. 

Further, there isn't much data supporting the switch from the general cat diet to a grain-free one. (Studies have not really compared "grain-free" to "grain-containing" regimens.) To close this knowledge gap, scientists compared 77 cat foods: 42 of these contained grain and the remaining 35 were grain-free. They discovered the following:

  • One of the recipes that was marketed as "grain-free" contained barley–a grain! Don't take these food labels at face value. Always check the ingredients list. 
  • The average grain-free formula had fewer carbs than the alternative. However, some contained higher levels of carbs than grain-containing options. 
  • Both types included animal-derived ingredients. These were mostly chicken, turkey, duck, eggs, and fish. However, grain-free diets contained "exotic meats" more than the opposite, often including venison, bison, and rabbit. 
  • Grain-free foods commonly included plant-based ingredients like peas, cranberries, potatoes, and carrots. The alternative usually had rice, fax, cranberries, and oats instead. 

So, what does all of this mean? Unfortunately, this means that there is no conclusive evidence that grain-free diets are better for cats… yet. Because of all the differences in ingredients, it's inaccurate to conclude that the absence of grains is responsible for any associated health benefits. 

These effects could be attributed to the unique benefits of exotic meats, reduced carbs, or a mixture of plant-based ingredients. So, if you're considering switching your cat to a grain-free diet, it's best to talk with your veterinarian. Together, you can determine the exact health advantages your cat needs and how to best attain them. 


There are several types of diet cat food, all of which stem from the cat’s core nutritional needs. If you're considering a switch to a specialized weight loss or grain-free  meal plan, contact your veterinarian first. 

Mistakes such as over- or underfeeding may lead to worsened health problems, and false marketing could leave you with no results at all. Expert guidance can make all the difference for your feline friend. 

About the Author

My name is Jazmin "Sunny" Murphy, and I am a science communicator and web content writer. Since 2015, I've been producing scientific content that is written in plain English. My love for life science has influenced my professional and academic aspirations since I was a kid. I hold a Bachelor of Science in Zoology and 21 units of a Master's education in Environmental Policy & Management (concentration: Fish and Wildlife Management). You can learn more about me and my science writing and reporting work at my website, Black Flower Writing Services.

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