Health Risks for Overweight Cats

Cats in particular are falling victim to the obesity epidemic for reasons we may not easily recognize.

Americans comprise one of the fattest societies on the planet and 1 out of 3 adults is overweight or obese. These alarming statistics are also true for our pets. Obesity in pets is defined as those who weigh 20-25% above their ideal bodyweight.(1)  Cats in particular are falling victim to the obesity epidemic for reasons we may not easily recognize. Several things must be considered when exploring the causes and health effects of feline obesity.

While genetics play a small role in feline obesity, themost common causes include having a sedentary lifestyle and consuming too many calories. More cats than ever are living indoors only, which can greatly diminish the amount of physical activity they receive. Cats are carnivorous hunters in nature, constantly on the prowl and eating what they catch in small, frequent meals. It is important to provide your cat with outlets for exercise if they live exclusively indoors- such as a ‘cat condo’ for climbing and lounging, toys or safe access to a patio or balcony.

Some veterinary experts are now thinking that how we feed our cats is predisposing them to being overweight or obese. The metabolism of the cat has evolved to run off of the protein and fats of their prey- such as birds and mice. The domestic housecat eats completely differently and experts argue that this has a negative effect on their metabolism and predisposes obesity.(2)  Dry cat foods must contain high levels of carbohydrates in order to maintain their shelf life and easy-to-feed crunchy texture. These high levels of carbohydrate mean that less protein is being consumed and the cat’s metabolism is not working properly.  Due to these changes, cats eating dry commercial diets often have low muscle mass and high fat mass on their bodies. Dry cat foods also allow owners the opportunity to feed ‘free choice’- leaving as much food out as the cat wishes to consume- which encourages overeating.

Health Risks
Cats are very similar to humans in that their weight and lifestyle can predispose them to ‘Type-2 diabetes’ (Diabetes mellitus) or insulin resistance. Insulin is the ‘gate keeper’ that regulates blood sugar (glucose). Insulin escorts glucose into the cell where it is used for energy. Type-2 diabetes occurs when there is too much body mass and not enough insulin or when the body’s cells become ‘immune’ to the ‘escorting’ effects of insulin. If unregulated, diabetes can cause blindness, chronic infections, dental disease and premature death.  The treatment for diabetes in cats includes dietary management (high protein, low carbohydrate) and insulin therapy.  With proper management, many cats will lose weight and put their diabetes into ‘remission.’ The cats in ‘remission’ often only require continuation of weight management and proper diet to remain healthy.

Arthritis is another major problem among overweight and obese cats.  Increased weight load on the joints can cause more wear and tear than normal, causing premature cartilage damage. These cats become painful and are reluctant to jump, run and be active. The reduction in activity due to arthritis pain may also compound the problem of obesity due to a more sedentary lifestyle. Many of these cats need to be on a form of pain management at some point in their lives.  Treatment should always include a weight reduction plan and pain control such as glucosamine supplements, NSAIDs or narcotics when appropriate.

Treatment and Prevention
It is important to have your veterinarian examine your cat at least once a year.  Your vet can determine your cat’s body condition score and formulate a weight loss plan for your cat if necessary.  Cats lose weight best by being put on a high-protein, low-carbohydrate diet. This is not a fad diet, but one that is most closely adapted to what cats eat in the wild.  Their metabolism will begin to ‘correct itself’ on a high-protein diet, their appetite will become more regular (you may notice that your cat is less ‘ravenous’) and will build lean body mass and lose fat.(2)  It is best to transition your cat onto the new diet slowly and not go ‘cold turkey’ on the dry food.  Again, consult with your veterinarian for a specific plan for your cat. The best diets for weight loss are wet or canned commercial foods with protein content of 45% or higher. (2) Many veterinarians will recommend a product like Purina’s canned Fancy Feast or Hill’s Science Diet’s canned m/d diet.

It is important to maintain your cat’s weight throughout their lifetime. Providing outlets for exercise is a crucial step. If it is relatively safe to allow your cat to roam outdoors, this is the best option for daily exercise. It is recommended to feed your cat both wet and dry food from ‘kitten hood’ into the senior years. If your cat begins to look a little “fluffy,” cut back on the amount of dry food they are receiving.  It is always best to consult with your veterinarian about how much your cat should be eating based on their age and lifestyle.


  1. Laflamme, D. 2011. Tips That Work: Managing Obesity in Dogs & Cats (SA196).Western Veterinary Conference Proceedings. Veterinary Information Network.
  2. Zoran, D. 2012. Protein: The Key to Metabolism, Health, and Management of Obesity in Cats (SA199). Western Veterinary Conference Proceedings. Veterinary Information Network.
This news story is independently sourced and does not specifically endorse products or services offered by any company referenced in this article, or benefit from any association with any companies referenced.