why is my cat so skinny but eats all the time?
Cat Health and Wellness

Why Is My Cat Always Hungry But Skinny?

If your cat is eating lots of food but not putting on extra weight, you’re bound to be concerned. We know that overindulging in food leads to weight gain, so it’s hard to understand how a cat could overeat but stay very lean.

Parasitic worms (tapeworms, roundworms, and hookworms) can mean that your cat eats a lot yet loses weight. Diabetes, hyperthyroidism, and inflammatory bowel disease can interfere with food absorption. So, your cat may eat voraciously yet lose weight. Also, make sure that another pet isn’t eating your cat’s food.

Occasionally, neither medical nor psychological factors are to blame for a cat’s ‘excessive’ hunger. Your cat might be hungry because it’s not getting enough calories at mealtimes or the food quality is low.

Why Is My Cat Hungry All the Time?

Polyphagia is the medical term for excessive hunger. Hunger is a complex process that is affected by physical as well as psychological factors. As such, the cause of polyphagia is not always easy to discern.

Calorie Deficit

There’s a chance that your cat is genuinely hungry. This could be because you are not feeding it enough, another animal is stealing its food, or its energy needs have significantly increased.


If you feed your cat enough calories but the food is devoid of essential nutrients, it may develop incessant food cravings.

Psychological and Emotional

If your cat is bored or lonely, it might learn that begging for food gets it more attention. Not only that, but it may also become addicted to the sensory pleasure of eating, especially if they don’t have any other forms of stimulation and enrichment. If your cat is overeating due to psychological factors, you’d probably see some weight gain.

Physical Illness

If you’ve noticed some weight loss along with the increased appetite, your cat probably has an illness. Various diseases can cause polyphagia.

These diseases interfere with the cat’s hormones, metabolism, and digestive health. Unfortunately, many of these diseases are common in older age, but there are treatments available. So, if your cat is always begging for food, keep an open mind about why.

cat always hungry but very thin

Symptoms of Polyphagia in Cats

If you’re concerned about the severity of your cat’s behavior, see how many symptoms of polyphagia you can recognize:

  • Whining and begging for food at inappropriate times
  • Becoming aggressive when asking for food
  • Stealing food from the fridge, cupboards, another pet’s food bowl, or the dinner table
  • Eating very quickly, which may lead to regurgitation
  • Weight changes
  • Increased thirst, perhaps drinking inappropriate/stale liquid to quench their thirst
  • Eating non-food substances, such as dirt
  • Hyperactivity

If you can tick off many of these symptoms, it’s quite likely that your cat’s excessive eating is due to an endocrine or digestive disorder.

Calorie Requirements for Cats

A good owner would never knowingly underfeed a cat, but it can sometimes happen. A cat may go hungry if:

  • One family member assumes another family member has fed the cat.
  • Another pet is stealing food from the cat’s bowl, but it goes unnoticed.
  • First-time cat owners don’t always know how much food is appropriate, and some cat food labels aren’t clear about portion sizes.
  • Kibble is more calorie-dense than wet food. If owners switch from a mixed diet to a wet food-only diet, they may not increase the quantity of wet food by enough to satisfy their cat’s energy needs.
  • The cat’s energy requirements may change due to pregnancy/nursing, or recovery from physical trauma (surgery or illness).

According to NAS, an average domestic cat has the following daily kilocalorie (kcal) requirements:

  • Kitten – 200 kcal
  • Lean Cat (1 year+) – 280 -360 kcal
  • Obese Cat (1 year+) – 240 – 280 kcal
  • Cat Recovering from Physical Trauma (perhaps an illness or operation) – 360 kcal while recovering.
  • Pregnant/Nursing Cat – 600 – 850kcal

It does vary, but one pouch/sachet (1 serving) of wet cat food usually contains between 70 and 120 kcal. Dry kibble tends to provide more calories than wet food per portion.

Feeding Schedule for Cats

If your cat’s hunger seems out of control, consider how regularly you are feeding it. Cats love to graze on food throughout the day.

If you feed them 4-8 small meals per day at consistent intervals, your cat is less likely to experience hunger pangs. 

When it comes to feeding your cat, consistency is paramount. If your cat is forced to wait hours and hours for a meal, it’ll be ravenous by the time the food arrives.

If your feeding schedule is irregular, your cat may develop a condition called psychogenic abnormal feeding behavior. This can cause them to steal food, binge eat, and constantly pester you for food.

Why Is My Cat Eating A Lot But Losing Weight?

We’ll now explore the various explanations for weight loss among cats that seem to be eating plenty of food:


Once you’ve checked the calorie content, you should also check its nutritional content. Cats fed poor-quality cat food can develop nutritional deficiencies, even if they are consuming large amounts of food.

Cats fed leftovers may also develop deficiencies if they don’t consume a wide range of foods. Deficiencies in the following vitamins and minerals can increase a cat’s food cravings:

  • Iron
  • B12
  • Magnesium

If your cat is ravenously hungry all of the time, this might indicate that it lacks a vital nutrient in its diet. You can prevent this from happening by purchasing good-quality ‘complete’ cat food.

What if you’re already providing your cat with a nutritious, calorically dense diet, and it’s still constantly begging for food? In that case, your cat may have one of the following medical conditions:

Thyroid Issues

Hyperthyroidism is an endocrine disorder that’s relatively common in older cats. It occurs when the cat secretes too much thyroid hormone (T3 and T4) from the thyroid gland in its neck.

This speeds up the cat’s metabolism, thereby increasing appetite. Occasionally, hyperthyroidism can actually dampen a cat’s appetite. Here are some additional symptoms to look out for:

  • Weight Loss – This is common in cats with hyperthyroidism and it can happen rapidly.
  • Poor Coat – Cats with hyperthyroidism often develop a shabby, disheveled coat.
  • Vomiting – This is often a side-effect of excessive eating, but might also be a symptom of the primary disorder.
  • Hyperactivity – Meowing, pacing around, padding paws into the ground repeatedly.

If your cat is diagnosed with this condition, it will be prescribed medication. Occasionally, surgery is required to remove the thyroid gland. Scientists believe that a high iodine diet may aggravate the condition.

This is because iodine facilitates the production of thyroid hormones. As such, your vet may recommend cat food that’s very low in iodine.


Like hyperthyroidism, diabetes mellitus (type 2) is relatively common in aging cats (10 years+). Diabetes occurs when the pancreas doesn’t produce enough insulin, or the cells respond inappropriately to insulin.

If insulin is low, glucose cannot be transported around the bloodstream effectively. This can lead to lethargy and extreme hunger. Diet is thought to play a key role in the development of this disease. Unfortunately, some mass-produced cat foods contain large amounts of carbohydrates and hardly any protein.

This has contributed to the rise in type 2 diabetes. Cats living in the wild would eat a high-protein diet, so they may be less susceptible to this disease. Diabetes is sometimes quite difficult to distinguish from other diseases, although the Blue Cross has summarized the symptoms to look out for:

  • Urinating frequently
  • A thirst that can’t be satisfied
  • Being hungry all the time, no matter how much food is provided
  • Weight loss because the cat cannot absorb the sugars in food
  • Bladder infections
  • Weakness and lethargy

The standard diabetes treatment is insulin injections and improving your cat’s diet.

Feline Acromegaly

Acromegaly is linked to diabetes because cats with this disease have difficulty maintaining a healthy blood glucose level. As such, it’ll feel hungry and thirsty all the time and may have some of the other symptoms associated with diabetes. 

Feline acromegaly occurs when too much growth hormone (IGF-1) is produced in the pituitary gland. This results in physical changes:

  • A large body
  • Broad face
  • Larger than average feet
  • Protruding lower jaw
  • Bloating around the stomach area

If you notice these physical changes, along with an increase in hunger/thirst, you should consult a vet. If your cat is diagnosed with acromegaly, it cannot usually be ‘cured,’ but it can be managed.

Inflammatory Bowel Disease

If your cat eats a lot but is skinny, another possibility could be feline inflammatory bowel disease (FIBD).

FIBD occurs when the walls of the gastrointestinal (GI) tract become inflamed. The GI tract is comprised of the esophagus, stomach, intestines, and colon. Inflammation in any of these locations can cause FIBD.

Due to this inflammation, food cannot be absorbed properly, so it is usually thrown up as foamy vomit or comes out as loose stools. As you’d imagine, the cat cannot absorb enough nutrition from its food, so it’ll constantly feel hungry.

Scientists are still learning what actually causes FIBD. Given that FIBD can affect any part of the GI tract, there is a range of causes:

  • Food intolerances and allergies
  • Stress
  • Genetic abnormalities in the GI tract and immune system
  • Parasites
  • Bacteria in the stomach, intestines, and colon

Your vet may suggest switching to hypoallergenic cat food or managing stress in the household. If these treatments aren’t appropriate, your cat might be prescribed a course of antibiotics/anti-inflammatories.


Parasites can sometimes be the culprit for inflammatory bowel disease. Parasitic worms such as tapeworms, roundworms, and hookworms can interfere with digestion and increase a cat’s appetite.

If your cat frequently plays outside, or you have other pets in the household, the risk of contracting worms increases. Worms can be caught from fleas or from the soil where other animals have defecated.

The easiest way to detect worms is to examine your cat’s stools or vomit. Worms will usually be white/gray in color, although they are not always visible to the naked eye.

If you see worms, collect a small sample to take to the vet. This will ensure they get the most appropriate treatment. Worms can cause weight loss, malnutrition, and even death if they are not treated appropriately.

my cat is losing weight but eats constantly


Is there really a link between cancer and excessive eating? Having cancer may impact a cat’s appetite. For example:

  • A cancerous tumor may press on the GI tract. If this impairs digestion, this can make them feel hungrier than usual.
  • Some cancerous tumors secrete an excessive amount of hormone (IGF-1, for example), which can raise the cat’s metabolism, so it’s more difficult for them to satisfy their hunger.

Nevertheless, cancer is less common than many other conditions mentioned above, and cancer decreases rather than increases a cat’s appetite. Additional cancer symptoms include nosebleeds, discharge from eyes or mouth, seizures, and bloating/swelling.

Psychological Reasons Cats Overeat

If your cat is fed a good-quality diet, is fit and healthy, but is always begging for food, it may be experiencing psychological/emotional hunger. Scientists have termed this condition ‘psychogenic abnormal feeding behavior.’


If your cat doesn’t get much attention or opportunity to play, the sensory pleasure of eating may become central to its life. This can cause your cat to overeat or constantly beg for food.


Cats can develop an addiction to mealtimes due to the sensory pleasure of the food and the attention they receive at mealtimes.

This double-stimulation can be addictive for a cat and cause it to keep begging for food all the time. For example, if multiple family members feed the cat throughout the day, it may become addicted to food and the feeling of being cared for by multiple people.

If you feed your cat leftovers from the table, it may start to become addicted to the extra food/attention. Even if you refuse to feed your cat from the table the next day, it may still pester you for food.

According to the Telegraph, cats that beg for food may have a psychological ‘addiction’ rather than a physical need or a medical condition.

Fear of Starvation

This is quite common among cats who have been neglected and cats that have to share meals with others. If they don’t know when the next meal is coming, this can lead to bingeing and stealing food.

Granted, if your cat is overeating out of boredom or addiction, it’ll probably see some weight gain. However, owners are quite bad at recognizing weight gain in their own pets, especially if a cat has a long, thick coat. So, don’t be too quick to disregard ‘psychological hunger’ as a factor.

If a vet determines that there is nothing medically wrong with your cat, its excessive hunger may be caused by psychological factors. Alternatively, it may be experiencing genuine hunger pangs due to a calorie and nutrient-deficient diet.