Everything You Need to know About Weight Gain For Cats

If your cat is losing weight for no clear reason, it could mean something is wrong, especially in older cats.

Sometimes, cats just need more calories, but issues like a poor appetite, dental pain, stress, or health problems can also make it harder for them to gain weight.

If you want your cat to gain weight, start by finding out why they are underweight.

This guide shares tips on helping your cat gain weight, choosing the right foods, setting up a good feeding routine, and making simple changes so your cat can slowly reach a healthy weight.

Why Is My Old Cat Losing Weight?

Don’t assume weight loss in an older cat is just a normal part of aging. While senior cats may slow down, unexplained weight loss or a drop in appetite can signal a health problem.

Possible causes include dental issues, stomach or digestive problems, kidney disease, diabetes, hyperthyroidism, pain, stress, and other health conditions.

Some cats may also lose interest in food if they have trouble smelling, tasting, chewing, or digesting it.

That’s why it’s important to have your older cat checked by a vet if they are losing weight.

If your cat suddenly stops eating, eats much less than usual, or keeps losing weight, call your vet. Cats that go without food for too long can develop serious problems like hepatic lipidosis, also called fatty liver disease.

What Happens When a Cat Stops Eating?

When a cat doesn’t eat enough, its body uses stored energy. If this goes on for too long, fat can build up in the liver.

This can lead to hepatic lipidosis, a potentially serious condition that requires veterinary treatment.

So, don’t just wait for your cat to eat when they get hungry. If your cat won’t eat or has lost their appetite, talk to your vet instead of trying to force-feed or making big diet changes by yourself.

Why Isn’t My Cat Eating?

There are many reasons why an older cat might stop wanting to eat. Some are short-term, but others need a vet’s care.

1. Illness or pain

Health problems are a key reason to consider if your older cat stops eating or starts losing weight.

Dental disease can make chewing hurt, and problems with the kidneys, thyroid, digestion, or other organs can cause nausea, weakness, or less appetite.

If your cat is losing weight and you don’t know why, make an appointment with your vet.

2. Dental problems

Older cats often have dental problems. Sore teeth, swollen gums, or other mouth issues can make eating uncomfortable.

A cat might go up to its food, sniff it, and then walk away because chewing hurts. Your vet can check your cat’s mouth and suggest the right treatment.

3. Stress or changes at home

Cats like routine, and changes in their environment can affect how much they want to eat.

Moving, getting a new pet, changing routines, having visitors, or changing where your cat eats can all cause stress. Even bringing a cat into a home with a dog can temporarily change their eating habits.

4. Changes in food

Cats can be picky about their food. A new flavor, texture, brand, or feeding schedule might make your cat refuse to eat.

This often happens when you switch an older cat to a new diet. Usually, it’s best to make changes slowly unless your vet says otherwise.

5. Medication or vaccination

Some medicines and vaccines can make a cat lose their appetite for a short time. If your cat stops eating after starting a new medicine or getting a shot, watch them closely and call your vet if it lasts or gets worse.

What to Give Older Cats for Weight Gain

If your cat is underweight, focus on nutrient-dense, calorie-rich foods that provide the protein, fat, and other nutrients they need without requiring them to eat large portions.

Your veterinarian can help you choose the right food based on your cat’s age, weight, appetite, and health.

Food option	Why it can help	Examples
Wet cat food	Soft, aromatic, and often easier for older cats to eat	Pâté, mousse, minced or shredded formulas
High-calorie cat food	Provides more calories in a smaller portion	Calorie-dense adult or veterinary formulas
Kitten food	Usually higher in calories, protein, and fat than adult formulas	Wet or dry kitten food, if recommended by your vet
High-protein cat food	Helps provide protein needed to maintain muscle	Chicken, turkey, beef, or fish-based formulas
Cooked chicken or turkey	Can make meals more appealing and adds extra protein	Plain, cooked, unseasoned chicken or turkey as a topper
Cooked egg	Provides additional protein and calories	Plain, fully cooked egg in small amounts
Cooked fish	Can be an appealing source of protein and calories	Plain cooked salmon or other fish as an occasional topper

Wet Food or Dry Food?

Both can be suitable for an underweight cat. Wet food may be a better choice for older cats that have dental problems or a poor appetite because it is soft and usually has a stronger smell.

Dry food is more calorie-dense by volume and can work well for cats that prefer kibble and can chew comfortably.

You can also combine wet and dry food if your cat enjoys both.

What to Look For

Choose a cat food that is:

• Complete and balanced
• Rich in animal-based protein
• Adequate in calories and fat
• Appropriate for your cat’s age and health
• Appealing to your cat’s preferred flavor and texture

Don’t rely on treats, table scraps, or human food as the main way to increase your cat’s calorie intake. These foods should only be occasional additions to a nutritionally complete diet.

If your cat has a medical condition, don’t automatically choose the highest-calorie or highest-protein food. Cats with conditions such as kidney disease, diabetes, or gastrointestinal problems may need a specific veterinary diet.

8 Tips to Help an Old Cat Gain Weight

After your vet has checked your cat and treated any health issues, you can start helping your cat eat more.

The goal isn’t just to feed your cat more. Your cat needs a complete, balanced diet with enough calories and important nutrients.

Here are some tips to help encourage your older cat to eat.

1. Choose an appropriate cat food

If your cat is underweight, ask your vet about the best diet. Depending on your cat’s health, they might suggest a high-calorie food, a senior diet, or a special diet for a medical condition.

Choose food that gives your cat the nutrients they need, instead of using treats or human food to add calories.

If your cat has a health problem, the right diet will depend on that issue. What works for one senior cat might not be right for another.

2. Try wet food

Wet food can help cats who have trouble chewing dry food or like softer textures. It also has more moisture, which helps with your cat’s fluid intake.

Some cats just prefer the smell and feel of wet food.

If your cat eats dry food now, add wet food slowly instead of switching all at once.

3. Warm the food slightly

Cats often like food better when it smells stronger. Gently warming wet food can make it smell more and may help your older cat eat.

Warm the food just a little and mix it well before serving. Always check that it’s not too hot.

4. Offer smaller, more frequent meals

A big serving can be too much for a cat with a small appetite.

Try giving smaller meals several times a day. This can make eating easier and give your cat more chances to get enough calories.

Your vet can help you figure out how much food your cat needs each day based on their weight, health, and nutrition needs.

5. Make mealtimes quiet and comfortable

Older cats often eat better in a calm, familiar place.

Put your cat’s food bowl in a quiet spot, away from busy areas, loud noises, and other pets. If your cat has trouble moving, make sure food and water are easy to get to.

Some older cats find it easier to eat from a low or wide dish.

6. Experiment with flavors and textures

If your cat suddenly won’t eat a food they’ve always liked, don’t just think they’re being fussy.

Talk to your vet about trying different flavors, textures, or types of food. Some cats like pâté, others like chunks or shredded food. Some prefer fish, while others like poultry.

Finding a food your cat likes can really help them eat more.

7. Add a safe food topper

Adding a little bit of a cat-safe topper can make your cat’s usual food more appealing.

Your vet can suggest safe options, but don’t use a lot of table scraps, treats, or foods high in fat or salt. Never give foods with ingredients that are toxic to cats, like onions or garlic.

A topper should add to a complete, balanced diet, not replace it.

8. Keep track of how much your cat eats

If you’re helping an underweight cat gain weight, it’s important to keep track of their progress.

Measure how much food you give and how much your cat eats. Weigh your cat regularly with a pet scale or another reliable method.

If your cat keeps losing weight even while eating, refuses food, vomits often, has diarrhea, or shows other changes in behavior or health, call your vet.

How to Switch an Older Cat to New Food

Changing your cat’s food can be tough, especially if they’re picky. It’s usually easier to switch foods slowly instead of all at once.

Begin by mixing a little of the new food with your cat’s usual food. Slowly add more new food and less old food over about a week or longer.

Some cats take longer to adjust. If your cat won’t eat the new food, slow down the change instead of letting them skip meals.

Sudden changes in diet can cause stomach problems like diarrhea or vomiting in some cats.

If your vet has given your cat a special diet for a health problem, follow their instructions for making the switch.

Monitor Your Cat’s Weight and Behavior

Helping an older cat gain weight takes time. Don’t just focus on the number on the scale.

Watch your cat’s appetite, energy, grooming, litter box habits, and overall behavior. Changes in any of these can tell you something about your cat’s health.

Weighing your cat regularly can help you see if your feeding plan is working.

If your cat keeps losing weight or isn’t eating enough, your vet might suggest more tests, changes in diet, appetite boosters, or treatment for a health problem.

When to Contact Your Veterinarian

Don’t ignore a poor appetite or unexplained weight loss in an older cat.

Contact your veterinarian if your cat:

• Stops eating or eats significantly less than usual
• Continues to lose weight
• Has difficulty chewing or swallowing
• Vomits repeatedly or develops persistent diarrhea
• Becomes unusually tired or withdrawn
• Drinks or urinates much more or less than usual
• Shows other sudden changes in behavior

Older cats can hide signs of illness, so even small changes can matter.

Your Old Cat Deserves to Feel Good

Helping an older cat gain weight starts with finding out why they’re losing it in the first place. 

After you treat any health problems, you can help your cat eat by providing a balanced diet, trying different textures and flavors, warming wet food a little, serving smaller meals more often, and keeping mealtimes calm.

Most importantly, be patient.

Older cats can be sensitive to changes in food and routine. Work with your vet to find a feeding plan that helps your cat stay at a healthy weight and meets their needs.

For more information contact Innovet Pet Products today!

 

 

Sara Redding Ochoa, DVM was raised in north Louisiana. She graduated from LA Tech in 2011 with a degree in animal science. She then moved to Grenada West Indies for veterinary school. She completed her clinical year at Louisiana State University and graduated in 2015 from St. George’s University. Since veterinary school she has been working at a small animal and exotic veterinary clinic in east Texas, where she has experience treating all species that walk in the hospital. In her free time, she likes to travel with her husband Greg, bake yummy desserts and spend time with her 4-legged fur kids, a dog Ruby, a cat Oliver James “OJ”, a rabbit BamBam and a tortoise MonkeyMan.

Thanks for stopping by!
P.S. We Love You!

Sincerely,
The Innovet Team

Please do not ask for emergency or specific medical questions about your pets in the comments. Innovet Pet Products is unable to provide you with specific medical advice or counseling. A detailed physical exam, patient history, and an established veterinarian are required to provide specific medical advice. If you are worried that your pet requires emergency attention or if you have specific medical questions related to your pet’s current or chronic health conditions, please contact or visit your local/preferred veterinarian, an animal-specific poison control hotline, or your local emergency veterinary care center.

Please share your experiences and stories, your opinions and feedback about this blog, or what you've learned that you'd like to share with others.