Water as a Weight Control Measure

Updated: March 02, 2016
Published: June 01, 2012
Share this:

Obesity is one of the top health problems facing cats today. The Association for Pet Obesity Prevention estimates that 50 million cats are overweight or obese in the United States alone. All that extra body fat puts overweight cats at higher than average risk for diabetes mellitus, hepatic lipidosis (a potentially fatal liver disease), congestive heart failure, cancer, skin disorders, and musculoskeletal problems.

This probably isn’t news to you. Most educated owners know that their fat cats are not as healthy as they could be; but what they also know is that achieving meaningful weight loss is not easy. Recommendations from veterinarians typically center on feeding measured meals of a calorie-restricted diet. While this works for some pets, reaching and maintaining a target weight remains elusive for many others, which is why the results of a new study caught my attention.

The research was published in the Journal of Animal Physiology and Animal Nutrition and showed that cats consuming a dry diet to which an extra 40 percent moisture was added (in the form of tap water) gained weight more slowly after dieting and had higher activity levels than cats that ate the same dry food containing only 10 percent moisture.

The study mimicked what often happens when a cat is put on a diet. Scientists fed 46 cats dry food, restricting their caloric intake by 20 percent. Once their "diet" was over, the cats were offered the same dry food free-choice, either as-is or with 40 percent extra water mixed in.

The addition of water caused the diet to be significantly less energy dense and resulted in cats regaining weight more slowly than the cats eating the dry diet without added water. The finding of increased activity in cats fed a food with a lower caloric density is surprising and warrants more research.

Is feeding a moisture-rich diet the magic-bullet when it comes to feline weight loss? Probably not, but it is worth considering if you’ve tried to help your cat lose weight in the past without success.

Keep in mind that this is a small study that doesn’t directly address the question of whether or not a moisture-rich diet helps cats lose weight; the subjects just gained their weight back slower in this investigation. Whether they turn out to be positive or negative, the long term health effects-of this type of dietary manipulation were not evaluated.

I worry that essentially diluting a food in this manner for months or years on end could lead to an imbalanced diet and deficiencies in important amino acids, vitamins, minerals, and fatty acids that may cause more health problems than the resulting weight loss solves.

Weight loss plans work best when they are individually tailored to the patient’s own needs. Talk to your veterinarian about what type of food, exercise, feeding strategy, and monitoring program offers the best chance of success for your cat.

Dr. Jennifer Coates

Image: Eric Isselee / via Shutterstock