Low-carb diet

It was known well before the discovery of insulin^[1] that a low-carb diet would help diabetic humans survive much longer. It's not surprising, then, that low-carb diets are studied in cats and dogs with diabetes.

Both dogs and cats are able to convert protein into energy as well as into muscle. The average of most commercial dry pet foods is between 30-70% carbohydrates. Neither species in the wild would have a diet similar to this; both would consume far less than the 30% low-end estimate^[2].

It is certainly possible to produce canned pet foods without carbohydrates, but today's dry pet foods would be non-existent without them.

In Cats

Most commercial dry foods are not suitable for diabetic cats^[3]^[4]: they contain between 30% and 70% carbohydrates^[5]. Use the link below to calculate yours based on as-fed values requested from the manufacturer^[6] Carbohydrates are essential to the formation of dry pet food, adding structure, texture and form. Dry food could not exist in its current form without carbohydrates, mostly corn and other grains.

Even though there is a dry food for cats called Innova Evo Cat & Kitten^[7] that claims a 7 percent carbohydrate level, some caregivers have found that it did not produce reduced blood glucose levels as effectively as wet food with a similar carbohydrate rating. One of our case studies shows a 150 mg/dL point drop in blood glucose levels by removing EVO from a mixed wet/dry diet.

BD Diabetes and Dr. Plotnick, of Manhattan Cat Specialists in New York City, remind us that in the wild, cats eat mice, which nutritionally break down to being 3% carbohydrate, 40% protein, and 50% fat--low-carb^[8]^[9]. He goes on to say that while carbohydrates, in the form of glucose, are necessary to the body's cells for fuel, they are not a dietary must; cats metabolize protein quite well, turning that protein into glucose^[10].

Low-carb and studies

Recent studies (see links below) show that cats' diabetes can be better regulated and even sometimes brought into remission with a low-carbohydrate (sometimes called "Catkins", though more properly Hodgkins^[11]) diet. ( It's hardly surprising for cats, who eat about 5% calories from carbs^[12] in nature. Veterinarians are gradually switching their recommendations to a low-carb diet as well^[13]. The Feline Diabetes Message Board discovered the benefits of this diet along with "Zone" author Dr. Barry Sears and bestselling author Sherry Sontag, back in 1999.^[14]

Intervet^[15] brings up an interesting point re: the carbohydrates present in the low-carb diet. Drawing from Dr. Greco's 2001 study as reference^[16], they suggest that the carbohydrates of the low-carb foods chosen should be as low in the glycemic index^[17]^[18]as possible. This is echoed in the "Feeding the Diabetic Patient" presentation from Ohio State University's Endocrinology Symposium in 2006^[19]. Both sources recommend low-GI foods like barley and whole grains as carbohydrate sources for cats.

Switching to low-carb

For cats, it is not necessary to buy a prescription low-carb diet for uncomplicated diabetes^[20]. (And Purina's "DM", though well-balanced, may have poorer-quality ingredients^[21] than many standard commercial foods!) Instead, look at Janet and Binky's lists^[22]^[23]^[24] of commercial cat food nutrient breakdown in your country, and choose a food you can afford with carbohydrate content between 4 and 10% calories from carbohydrates. Lower than 4% seems to be too low^[25] in many people's experience, and can paradoxically cause higher blood glucose levels. Raw food with proper nutritional supplements are often best for both cats and dogs.

Note: The carbohydrates shown on the label (if they exist at all) will be by weight, not by calorie content. Use the list or the Excel spreadsheet at the link below^[26] to convert to calories from carbohydrates^[27] before comparing.

If switching to a lower-carbohydrate food, do it gradually, while hometesting blood glucose, and lower the insulin dosage appropriately, with your vet's help. A sudden switch can lower insulin needs^[28] dramatically and risks hypoglycemia. This is important enough that Dr. Greco, in an lecture at the District of Columbia Academy of Veterinary Medicine, suggests reducing insulin 25-50% when switching to a high-protein, low-carb diet^[29]. If your cat is on a special diet for pancreatitis, chronic renal failure, or any other condition, consult your vet for the appropriate diet for that condition plus diabetes^[30].

Merrick Pet Foods^[31]^[32] whose dog food won the Glycemic Research Institute three years in a row (shown below) offers this information regarding their canned cat food for cats with diabetes:^[33]

In Dogs

Diabetes in dogs is best treated by feeding a nutritionally sound diet. Good regulation using this method can be achieved either through use of strictly basal insulin or basal/bolus method. This is highly dependent on the individual animal's metabolism.

Owners who want the best for their dogs will take the time and effort to understand carbohydrate metabolism, insulin action, and home glucose testing. It is in this way they can best understand how food and insulin affect their pet.

Understanding carbohydrates

When we talk about carbohydrates, it also helps to know they break down into two categories: simple and complex. An example of a simple carbohydrate is lactose (found in milk); pasta and bread are examples of complex ones. One can go a bit further with this, knowing that both bread and pasta are made from grain--mainly wheat, to include other food items made from them.

The simple ones are rapidly converted to glucose and promptly raise blood glucose levels. The liver takes longer to convert the complex ones into glucose, and so they raise blood glucose levels more gradually. This is important to know when choosing foods for those with diabetes^[34].

There are two other terms for carbohydrate classification besides these are--soluble and insoluble. The terms refer to how easily they are broken down in the digestive tract.

Soluble carbohydrates are grains, such as wheat, rice, barley, oats and corn. When cooked and present in pet foods, digestion is easy and rapid.

Insoluble carbohydrates are those we refer to as fiber, which pass through the intestinal tract without being digested^[35]. Bran,corn and its by-products, soy fiber, and beet pulp are some examples found in pet foods. Merrick Pet Foods^[36] produces high-quality dog and cat food. The Glycemic Research Institute, which tests both human and pet foods with an eye on the glycemic index and other properties important to diabetics, has awarded Merrick Best Pet Food of the Year (their third consecutive year of winning) for 3 of their dog food flavors^[37]. The food can be purchased from local retailers^[38] in the US and Canada or from the company's online store with no shipping charges for the contiguous US^[39].

Special considerations/complications

It may be in the best interests of the particular pet in question that a diet not so high in fiber be utilized, due to other health considerations^[40] or that the pet refuses to eat commercial pet foods higher in fiber. In these cases, home preparation of food may be the only solution. Many people prepare meals for their diabetic pets who have no need of additional bolus insulins.

Some other conditions that sometimes occur with diabetes, including pancreatitis, liver problems, or chronic renal failure^[41], may be incompatible with a low-carb diet. In that case, many animals are forced to use a specially-tuned medium-carb diet with special ingredients/restrictions for their condition. Consult your veterinarian.

Supplements

Certain dietary supplements can help with diabetic cats and dogs. Antioxidants can help reduce or reverse damage from hyperglycemia. Chromium can help lower blood glucose levels, L-Carnitine plus a calorie-restricted diet can control weight, and Methyl-B12 can help reverse diabetic neuropathy.

References

[1] Discovery of Insulin

[2] Carbohydrates as Energy Sources if Pet Foods--Pet Eduation.com-Drs. Foster & Smith

[3] Dr. Deborah Greco on proper diabetic feline nutrition

[4] Dr. Lisa Pearson on proper feline nutrition and why dry food is unsuitable

[5] Pededucation.com-Carbohydrates in Cat Foods

[6] Feline Diabetes Library Posts

[7] Natura Pet Products Website: Innova EVO Cat and Kitten

[8] Manhattancats.com-Diabetes, Obesity & Diet

[9] BD Diabetes-Diet & Exercise for Diabetic Cats

[10] Manhattancats.com-Diabetes, Obesity & Diet

[11] U.S. Patent 6,203,825 treating diabetes in obligate carnivores using a low-carbohydrate diet, Dr. E. Hodgkins, DVM, Esq.

[12] Are We Feeding Cats Too Many Carbohydrates?-Dr. Lisa Pierson

[13] Feline Diabetes Management-Diet-North American Veterinary Conference-2006

[14] Story of how the FDMB discovered the benefits of low-carb diet for cats

[15] Intervet-Caninsulin-What to Feed the Diabetic Patient (Page 11)References (Page 16)

[16] Comparing High Protein/Low-Carbohydrate to High-Fiber Diet in Feline Diabetes mellitus-2001

[17] Glycemic Index-How It's Measured

[18] Glycemic Index of Foods-Glycemic Index Values

[19] Feeding the Diabetic Patient-Page 34

[20] BD Diabetes-Diet & Exercise for Diabetic Cats

[21] Feline Diabetes Message Board--Food Discussion

[22] Canned Cat Food List

[23] Dry Cat Food List

[24] Non-US Cat Food Brands List

[25] Feline Diabetes Library: Low Carb Foods

[26] Janet's Spreadsheet

[27] Discussion of different conversion methods with links, from FDMB

[28] Feline Diabetes & Diet-The High-Carbohydrate Culprit? Dr. Lisa Pierson

[29] DA Academy of Veterinary Medicine-Lecture Notes-Endocrinology-March 2001

[30] Intervet-Caninsulin-What to Feed the Diabetic Patient (Page 11)

[31] Foods Merrick Pet Foods Website

[32] Glycemic Research Institute-Merrick Dog Food Wins Again-2006-2007

[33] Merrick Pet Foods FAQs-Canned Foods

[34] Log Beach Animal Hospital

[35] Fiber in Pet Foods-Pet Education.com--Drs. Foster & Smoth

[36] Merrick Pet Foods Website

[37] Glycemic Research Institute: Merrick Pet Food Named Best Pet Food of the Year-2006-2007

[38] Merrick Pet Food: Locate a Retailer Near You

[39] Merrick Pet Food-Online Store

[40] Vetsulin-Feeding Schedule

[41] Tanya's Feline CRF Information Centre

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