What is a ketogenic diet for dogs and cats?
The most simple explanation of what a ketogenic diet is, is a diet that utilises fat as fuel, instead of carbohydrate. Most, if not all, current pet foods rely on carbohydrate as the major source of fuel (calories), and this is driven primarily by cost, as carbohydrate is cheap, and by a mistaken belief that carbohydrates are a good source of energy. The human food pyramid has long held this mistaken belief, both promoting complex carbohydrate as the most important and substantial component of a balanced diet, and simultaneously demonising fats as being bad for health, and limiting them to a very small portion of the diet. Further complicating this has been another long held myth that saturated fats (primarily animal fats) are the worst kind, and that they should be replaced with vegetable based unsaturated fats.
The unfortunate reality of this very un-scientific approach to nutrition in the western world has been the alarming increase in obesity, type 2 diabetes, heart disease and cancer, and sadly we are seeing this being mimicked in our domestic pets. The truth is, carnivores, both obligates (felines) and facultative or opportunists (canines) are fully designed and evolved to obtain their energy needs from fats, not from carbohydrate – which makes perfect sense when you think about their natural diet of prey animals.
How a fat-fuelled ketogenic diet differs to a carbohydrate-based, traditional pet food diet
The hormone responsible for dealing with carbohydrate based fuel is insulin. When carbs are broken down into simple sugars like glucose and fructose and absorbed into circulation, insulin is released into the bloodstream and it facilitates the uptake of sugars into the cells, where it can be burned as fuel, or, more importantly, if there is no requirement for the fuel, it can be converted and stored as body fat. When carbs are not available, the body will then utilise fat as a fuel source. Fats are broken down into small complexes called ketones which can be utilised as energy by the cells – hence the name ketogenic – a diet that generates ketones.
If ready sources of fat from the diet have been utilised as fuel, then the body then turns to its fat reserves to next provide the ketones. I apologise that this is a very simplified explanation of what is actually a very complex system, but in essence, this is the way the body handles the two main fuel sources. Fat actually yields 4-5 times more energy, per gram, than carbohydrate, so it is much more energy dense. A diet that has 20% fat would be the energy equivalent of a diet with 80% carbs. Under extreme conditions like starvation or malnutrition (and with some metabolic diseases), the body will break down proteins (eg muscle tissue) to create sugars than can be utilised as fuel, but this is a very energy inefficient process.
How excessive carbohydrates can contribute to health problems
So, how do we use this basic knowledge to understand the importance of fats as fuel ? The two most prevalent conditions in western society that impact health, and are also significant issues with pets, are obesity and diabetes. When the body uses carbs as fuel, there is a constant demand for insulin to facilitate energy production. With type 2 diabetes, the consistent high levels of insulin causes the body cells to gradually become “resistant” to the effects of insulin, and as a result, blood sugar is not able to enter the cells to provide fuel, and blood sugar levels remain high (type 2 diabetes). Another contributing factor in pets is the damaged function of the cells that produce insulin in the pancreas over time, which results in true diabetes (insulin dependent diabetes).
Due to the consistent source of dietary carbohydrate, excess blood sugar is also constantly being converted to fats as a storage mechanism (driven by the high insulin levels), which then accumulates as body fat. Given that most pets, and people, rarely experience times of true fasting – which is when body fats are then burned as a fuel source – this body fat simply slowly accumulates over time, leading to obesity. Compounding this, is the fact that the very type of energy production in the cells (driven by small structures called mitochondria) when fuelled by sugars, has been shown to enhance cellular degeneration over time, and is directly involved in the formation of cancer cells – apologies again for this simplified explanation.
So, from this we can see how a diet based on carbohydrates is driving disease.
Why strangely a ketogenic diet can help your pet lose weight
When we look at fat as a fuel source, we actually see a very different picture. Ketogenic diets (based on protein, fat and leafy vegetable matter) do not drive, or even require, insulin to create energy, and as such, are absolutely indicated as a first line approach to dealing with diabetes. And whilst it may seem paradoxical, these fat based diets are also the quickest and easiest way to loose weight, both for pets, and people. By limiting insulin production, we halt the storage of fat, and stimulate the body’s ability to mobilise and burn body fat stores as fuel. When combined with periods of fasting – this is where feeding one main meal per day can have such great metabolic effects – where the intake of food / fuel is limited to a small period of time during each 24 hr period – ideally within a 6 hour time frame, or less, fat stores are quickly utilised as a consistent source of energy, and rapid and sustained weight loss occurs. Because fats as fuel are so energy dense, there is an increase in the production of leptin, a hormone that decreases hunger and is released when fat is metabolised, and this in turn reduces the urge to eat, or over-eat, which is the opposite on a carb rich diet.
Ketogenic diets and cancer
The final, and perhaps most important role for ketogenic diets is in the management and prevention of cancer. By removing sugars as a fuel source, and thereby reducing circulating insulin, cellular metabolism at the level of the mitochondria is normalised, and intracellular damage is stopped, and even reversed. This is the simple basis behind the reason why sugar feeds cancer. This simple yet profound strategy should be a first line approach to managing any pet (or person) diagnosed with cancer.
Ketogenic diets have also been shown to have very good results in managing epilepsy and seizures, and are a first choice for working dogs (and athletes). And just as a side note – heart disease caused by arteriosclerosis in humans (something we gladly don’t have to deal with in pets) is not a disease driven simply by high cholesterol (blood fats), but is caused when we combine high sugars and insulin resistance as well, which leads to inflammation (from glycation of excess sugars) and the deposition of inflamed fatty deposits on the arterial blood vessel walls, which in turn, narrow arteries leading to constriction, blockages, heart attacks and strokes. If you choose a ketogenic diet, you need to remove those carbs and sugars from the diet !!! Fat AND sugar is a bad combination.
Ketogenic recipes and food for dogs and cats
The basics of creating a sustainable ketogenic diet are pretty simple. The diet needs to provide most of the calories in the form of fats – and for dogs and cats, this means animal fats and some additional vegetable sources like coconut oil, flax seed oil and fish oils. A simple rule of thumb is utilise meats that are high in fats naturally, like lamb and even pork. Selecting higher fat cuts, or high fat minces (many pet minces are high fat).
For dogs, aim for 80% high fat meat/mince, and 15% leafy vegetable matter, with max 5% complex carbohydrate. The meat needs to have at least 20-30% fat content – so adding coconut oil, omega 3 fats (flax/fish/krill oil) and vitamin E may be required. For every 1kg of lamb (average 20% fat), add 2 tablespoon of coconut oil, 20ml of omega 3 oil, and 1000 IU of vitamin E. For simplicity, you can utilise my Complete Mix Grain Free base and add extra pulped green veggies, then add the fatty meat.
For cats, go for 90-95% fatty meats, and 5-10% green vegetable matter, with zero carbs. And remember, always combine some good quality organ meats in the meat portion of the diet (say 10%).
More extreme ketogenic diets can be utilised for treating cancer patients and in stabilising diabetics, and can contain up to 70% fat, but these diets should be well formulated and introduced in consultation with an educated veterinarian.
Transition to a ketogenic diet slowly
Transitioning to a high fat diet does need to be done gradually, especially if coming from a carb based diet. The body needs to transition from burning carbs as fuel, to utilising fats, and you don’t want to stir up the pancreas by a sudden surge in fat content. Always take 10-14 days to gradually make this change. With older patients that may have cancer or diabetes, I will always advise adding a pancreatic enzyme supplement (eg Enzyplex powder) long term. It can also assist in the transition process for all pets. Because fats are quite volatile, and will go rancid quite easily, they do not preserve well in most shelf stable pet foods, and as such, the best ketogenic diets and our Complete Mix Grain Free muesli can be used as a base.
Dr Bruce Syme BVSc (Hons), Founder of Vets All Natural.
Dr Bruce Syme is a practicing vet and expert in natural pet nutrition, has spoken at the Australian Veterinary Association Annual Conference, and provides regular comment on TV and Radio.
Disclaimer: The entire contents of this article are based upon the opinions of Dr. Bruce Syme, unless otherwise noted. The information is not intended as medical advice, it simply shares the knowledge and information from the research and experience of Dr. Bruce and his community. Pet health care decisions should be based upon your research and in partnership with a qualified pet health care professional.
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