Aging

As animals get older, their ability to digest food, especially fats and proteins, decreases and it can lead to a calorie deficit and excessive hunger. 

“Fat provides twice as many calories in every gram as protein or carbohydrates,” Dr. Murphy says. “If you lose your ability to digest that fat, it results in a calorie deficit. The cat has to start eating more to get the calorie load in.”

“We would want to first rule out diseases like hyperthyroidism, diabetes, intestinal diseases and lymphoma before saying it’s just aging,” she says.