In North America, obesity is the most common preventable disease in cats and is one of the most common overall. Almost 60% of domestic cats are overweight.
What is obesity?
Obesity is an accumulation of excess body fat.
As extra body fat causes extra body weight, weight can be measured to determine if a cat is overweight or obese. This is much easier than trying to measure body fat. Using body weight as a guide, cats are considered overweight when they weigh 10-20% above their ideal body weight. Cats are considered obese when they weigh more than 20% above their ideal body weight.
What are the risks posed by obesity?
Obesity shortens a cat’s life and makes them more likely to develop diseases. Even being moderately overweight reduces a cat’s life expectancy. A 2.8-fold increase in mortality has been shown in obese cats (8-12 years old) compared to lean cats.
A large lifetime study of Labrador Retrievers found that a moderately overweight group of dogs lived nearly two years less than their leaner counterparts. This is a sobering statistic, as it was always accepted that heavy dogs lived a shorter time than lean dogs, but only by about 6-12 months. It is reasonable to expect we would see similar results in a study performed on overweight cats.
"Scientific evidence now reveals that fat tissue is biologically active; it secretes inflammatory hormones and creates oxidative stress on the body’s tissue, both of which contribute to many diseases and decrease quality of life."
Previously, fat was considered a relatively inactive tissue, simply storing excess energy calories and adding to body mass. Scientific evidence now reveals that fat tissue is biologically active; it secretes inflammatory hormones and creates oxidative stress on the body’s tissue, both of which contribute to many diseases and decrease quality of life. Treating obesity as a chronic, low-level inflammatory condition is the new approach.
Obese cats develop an increased risk for:
- Diabetes mellitus
- Heart disease and hypertension
- Osteoarthritis and faster degeneration of affected joints
- Urinary bladder stones
- Anesthetic complications
Obese cats who stop eating are at significant risk for developing a potentially life-threatening liver condition called hepatic lipidosis. Other potential complications of obesity in cats include skin and coat problems and difficulty fighting infectious diseases.
How can I tell if my cat is obese?
The first step in dealing with an overweight or obese cat is to recognize and acknowledge that there is a problem. Unfortunately, we are inundated with images in the media of overweight cats, making it challenging to understand what healthy looks like. Your veterinarian and veterinary health care team can assist with an assessment.
Fat coverage over the ribs is an important measurement to help you identify if your cat is overweight and is easy to do yourself at home. Compare your cat’s ribs to the knuckles of your hand—hold one hand out, palm facing down, and run the fingers of your other hand across the knuckles—a cat with a healthy body condition will feel similar over the ribs. Next, turn your hand palm facing up and run your fingers on the knuckles in your palm—if your cat has a similar definition or less across the ribs, he is likely overweight. Finally, run your fingers over the knuckles with the hand in a tight first—if your cat’s ribs feel this defined, he is likely too thin.
Your veterinary health care team will provide an estimated ideal body weight to use as a target. Still, it is important that they also do regular body condition assessments to ensure your cat is moving toward having a normal body weight and body condition. Most veterinary practices use a body condition scoring system on a scale of either 1-5 (3 being ideal normal) or 1-9 (5 being ideal).
"Your veterinary health care team will provide an estimated ideal body weight to use as a target."
How do I adjust my cat’s meals to help him lose weight?
Once you have identified that your cat is overweight or obese, it is essential to adjust feedings for weight loss using an appropriate nutritional product, portion, and meal frequency. Veterinary-formulated diets help with healthy and safe weight reduction in cats, such as Hills® Prescription Diet Metabolic, Royal Canin® Satiety Support Weight Management, and Purina Overweight Management®. It is NOT appropriate to simply reduce the volume of their current food. This will cause malnourishment over time.
"It is NOT appropriate to simply reduce the volume of their current food. This will cause malnourishment over time."
Feeding a special diet with lower overall calorie density and an appropriate nutrient balance is essential. Your veterinarian can recommend and provide the diet best for your cat.
Once the new food has been selected and the new portions are determined, it is critical that you be consistent with feeding – portions and meal frequency – and resist the temptation to provide extra snacks. Ask your veterinarian how to include treats in your cat’s diet plan.
Monthly weigh-ins are a critical component of successful feline weight loss and keep everyone accountable. It is important to verify weight loss, to ensure that weight loss is neither too rapid nor too slow, and to determine when your cat has achieved a healthy body condition.
For more tips on reducing your cat’s weight, see the handouts “Creating a Weight Reduction Plan for Cats” and "Exercising Your Cat for Weight Loss".
What happens when we reach our weight loss goal?
Once ideal body weight and condition have been achieved, it is important to maintain your cat’s weight. It is important to gradually increase the amount you feed your cat while he maintains this healthy weight until he can safely transition to a maintenance diet (think of it as a ‘reverse diet’ to help his metabolism adapt to a ‘normal’ amount of food). This process can take two to three months but is the best way to prevent a weight gain rebound. Some cats, especially those who exhibit begging behaviors and are less active, may benefit from remaining on the weight loss diet long-term with slightly higher meal portions for maintenance. Your veterinary team can guide you through this process.
Portion control is critical at this stage to prevent regaining weight. After so much hard work, a relapse into obesity would be unfortunate. Yo-yo weight loss and gain are no healthier for cats than for humans. The benefits of normalizing body weight and condition make the effort well worth it.