Does your cat lie around all day, only getting up to eat and visit the litter box? Chances are, he’s overweight. Maybe you’ve switched to the “diet” cat food or tried feeding him less, but you might have noticed it’s not easy to get that weight off. A new study from the University of Illinois explains what it takes to get kitty to slim down.
It turns out you have to keep reducing their food intake because they’re not very active. It takes a long time, says Kelly Swanson, Kraft Heinz Co. Endowed Professor in Human Nutrition in the Department of Animal Sciences and the Division of Nutritional Sciences at U of I.
Swanson and his colleagues wanted to target a safe level of weight loss – enough to notice a change, but not enough to cause health problems.
“The risk with rapid weight loss, especially in a cat, is hepatic lipidosis. The body releases too much fat, and the liver gets bogged down. They can’t handle that much,” Swanson says. “We targeted a 1.5 percent body weight loss per week, which falls in line with the range (0.5-2 percent per week) suggested by the American Animal Hospital Association.”
To achieve that 1.5 percent loss, the researchers had to cut food intake by 20 percent compared to a maintenance diet. But that was only the first reduction. Swanson and his colleagues found that to achieve continued weight loss, they had to keep cutting intake every week.
“That’s a key point. When we go on a diet ourselves, we might lose a lot of weight in the first few weeks and then hit a road block. Same with these animals. We had to keep going down, but it can be hard to convince a pet owner to do that.
"You might get owners to reduce intake from 60 to 50 grams per day, but we’re telling them they might have to go to 45 or 40 grams. We got really low, but we were monitoring them so they were healthy,” he says.
The goal was a healthy body condition score of 5 on a 9-point scale. An animal with a BCS of 1 is very emaciated, but one with a score of 9 is, as Swanson puts it, “like a little blimp.” An animal with an ideal BCS of 5 has a little layer of fat on the ribs, but has a tuck at the waist.
As hard as it may be to convince owners to reduce their cats’ food intake, it might be harder to convince them that their pets are overweight in the first place.