Starving for Attention. What Happens When You Don’t Feed Your Cat for 24 Hours


This article will discuss what happens if a cat goes without food for 24 hours. Cats are obligate carnivores and need to eat regularly to stay healthy. Going without food, even for a short time, can have effects on a cat’s metabolism, organ function, gastrointestinal system, and behavior. We will outline the mild effects seen within the first day of not eating as well as more concerning impacts if fasting continues. Understanding the repercussions of not feeding cats will underscore the importance of providing them with consistent meals.

Mild Effects After 24 Hours

If a cat goes without food for 24 hours, some mild effects may start to appear. The most common effects after a day without eating include lethargy, increased vocalization, and searching or begging for food.

After not eating for 24 hours, a cat will start to feel more tired and lethargic since it is not getting calories and nutrients from food [1]. Cats normally sleep over 50% of the day, but they may sleep even more and move around less when hunger sets in.

You may also notice your cat meowing and vocalizing more as it tries to alert you that it wants food [2]. This increased vocalization is your cat’s way of telling you something is wrong and asking to be fed.

In addition to meowing, a hungry cat may start searching around for food, going to their empty food bowl repeatedly, or begging for food from their owner [3]. This food-seeking behavior is another mild sign of hunger after a day without eating.

Effects on Metabolism

When a cat goes without food for 24 hours, its body starts metabolizing its fat and protein stores for energy [1]. The body first breaks down glycogen in the liver and muscles. Once glycogen is depleted, the body starts mobilizing fat, converting it to fatty acids and glycerol. Fatty acids can be used by most tissues in the body for energy. After about 24 hours without food, the body also starts breaking down its own muscle protein to produce glucose through a process called gluconeogenesis [2]. This breakdown of fat and muscle provides the energy the cat needs to function.

Effects on Organ Function

When a cat goes without food for 24 hours, its body begins breaking down fat reserves for energy. This process taxes the liver and kidneys, which must work harder to metabolize the fat. According to PetMD, the liver helps process fat into fatty acids and glycerol, while the kidneys filter out waste products from this process.

The liver and kidneys essentially have to work overtime when a cat fasts for a day. Prolonged fasting can potentially lead to liver damage or dysfunction. According to one source, fatty liver disease is a risk if a cat goes too long without eating [1]. The kidneys can also become stressed and inefficient at filtering wastes.

Overall, not eating for a full day places significant metabolic demands on a cat’s liver and kidneys. These vital organs work hard to supply energy in the absence of food intake. Extended periods without food can potentially lead to organ dysfunction or damage in cats.

Gastrointestinal Effects

Not eating for 24 hours can have various effects on a cat’s gastrointestinal system. An empty stomach leads to nausea and stomach upset in cats (source). The lack of food moving through the digestive tract causes the stomach to produce excess acid, sometimes leading to vomiting of yellow bile when the stomach is very empty (source). Cats may also experience diarrhea or constipation from not eating for a day, as their intestinal motility decreases without food stimulation (source). Overall, an empty digestive system leads to gastrointestinal upset and discomfort in cats.

Behavioral Changes

When cats do not eat for 24 hours, they often become more vocal as a way to express their hunger and food-seeking behaviors. A cat that is hungry is more likely to meow loudly, yowl, chirp, or make other vocalizations to get their owner’s attention and ask to be fed.[1] Increased vocalizations from a normally quiet cat can indicate the cat is very hungry and urgent for food.

Missing just one meal can also cause cats to act more irritable or impatient. They may pace around the kitchen, stare more intently at their owner, or meow persistently when it’s time to be fed. Cats that are used to being fed on a set schedule may start demanding food earlier and earlier in the day. A lack of food can disrupt a cat’s routine and lead to increased vocal demands for meals.[2] These behaviors are signs a cat’s hunger is disrupting their normal temperament.

Overall, increased vocalization, irritability, and persistent food-seeking behaviors are common ways a cat expresses hunger after missing a single daily feeding. However, if these behavioral changes persist beyond 24 hours without eating, it can indicate an urgent need for medical care.

Weight Loss

Cats can lose weight rapidly when deprived of food, even for just 24 hours. According to WebMD, cats that go without food for a day may lose up to 1% of their body weight in that time (source). For a 10 pound cat, that’s about 2.2 ounces of weight loss.

Cats have a very high metabolism compared to humans, so they burn through calories quickly and can’t withstand long periods without food (source). Their liver rapidly starts breaking down fat and muscle tissue to supply energy when deprived of food. Prolonged fasting leads to more severe weight loss and muscle wasting.

According to WagWalking, healthy adult cats shouldn’t lose more than 1-2% of their body weight per week (source). Rapid weight loss greater than this normal range could indicate an underlying health issue or lack of food. Owners should monitor their cat’s weight and appetite closely and contact their vet if abnormal weight loss occurs.

Effects on Disease

Not eating for 24 hours can be especially dangerous for cats with certain medical conditions like diabetes, kidney disease, liver disease, or hyperthyroidism. These diseases impair the body’s ability to regulate blood sugar, filter waste, or metabolize nutrients from food. When a cat already struggling with these conditions stops eating, it can quickly lead to complications.

For example, cats with diabetes depend on regular meals to manage their blood sugar levels. If a diabetic cat goes too long without food, they are at risk of developing a life-threatening condition called ketoacidosis from having extremely high blood sugar. This requires emergency medical treatment.

Cats with kidney disease often have reduced appetite due to buildup of toxins in their blood that make them feel nauseous. But not eating leads to muscle wasting and further kidney damage. These cats need careful monitoring of calorie intake.

Similarly, cats with liver disease or hyperthyroidism will deteriorate rapidly if they go off food. Their diseased organs are less able to supply the body with essential nutrients during starvation. Cats with these conditions should see a vet promptly if they go more than 12 hours without eating.

In short, letting a cat with an underlying condition go without food for 24 hours can seriously endanger their already vulnerable health. Their illness makes it critical to identify the reason for appetite loss early and provide care.

When to Worry

If your cat goes more than a day without eating and shows signs of extreme lethargy, vomiting, diarrhea, difficulty breathing, or collapse, this indicates an emergency situation requiring immediate veterinary care ( Not eating for over 24 hours can quickly lead to potentially fatal complications such as hepatic lipidosis, especially in overweight cats ( If your cat is displaying any of these worrying symptoms along with not eating, do not wait – seek veterinary help right away, as delaying treatment can greatly reduce the chances of recovery.


In summary, not feeding a cat for a day can have a variety of effects, ranging from mild to severe depending on the health and age of the cat. Within 24 hours, a cat may exhibit increased hunger, irritability, vocalization, and other behavioral changes as their metabolism slows down and their stomach empties. Prolonged lack of food can cause liver and kidney problems, gastrointestinal issues, dangerous weight loss, hypoglycemia, and more. Kittens, senior cats, and cats with medical conditions are most vulnerable. While an adult healthy cat may tolerate a single missed meal, regular daily feeding is vital for a cat’s health. Kittens and older cats especially should never go more than 12 hours without food. Overall, cats require a consistent daily meal routine to meet their nutritional needs.

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