My Cat Is Losing Weight but Eating More. How Is That Possible?
It seems contradictory.
Your cat is asking for food more frequently—perhaps even eating enthusiastically—but somehow becoming thinner.
In a middle-aged or older cat, this combination deserves attention because it is one of the classic patterns associated with hyperthyroidism.
Hyperthyroidism occurs when the thyroid glands produce excessive thyroid hormone. Cornell describes it as a common disease of middle-aged and older cats.
What might owners notice?
Typical changes include:
- Weight loss despite an increased appetite
- Increased thirst and urination
- Restlessness or hyperactivity
- Vomiting or diarrhoea
- An unkempt or greasy coat
- Increased vocalisation
- A rapid heartbeat
Not every cat develops every sign, and early changes may be subtle.
Why does it matter?
Thyroid hormones affect almost every organ system.
Untreated hyperthyroidism can therefore affect the cardiovascular system and may occur alongside other age-related conditions such as kidney disease.
Diagnosis commonly begins with examination and measurement of thyroid hormone in the blood.
The encouraging part is that several treatment approaches are available, including medication, dietary therapy, surgery and radioactive iodine, depending on the individual cat and local availability.
What can owners do?
For senior cats, make weight monitoring part of normal home care.
Even weighing once monthly can reveal a trend that your eyes may miss.
If your cat is eating well but steadily becoming thinner, don’t simply increase the food and wait.
What We Often See in Practice?
Owners are often relieved when we explain that their cat’s enormous appetite isn’t necessarily because they haven’t been feeding enough.
Sometimes the body is simply running at an abnormally high metabolic rate.
One Thing Every Pet Owner Should Remember
A good appetite doesn’t always mean good health—especially when your cat is losing weight.