Grain Free Diets
Dr. Dave looks at the diverse grain-free category* (dry foods only) to help you make the right choice for your pet
By Dave Summers, Ph.D, Nutritionist
It’s actually difficult to generalize about grain-free diets as a category. The diets vary widely between brands and when you make recommendations you really need to match the diet to the pet. That said, I’ll still refer to grain-free foods as a category for lack of better terminology.
Denis McLaughlin, Vice President, Merchandising, provides this definition: “It’s taking the no wheat/no corn direction of pet food development to the ultimate destination of ‘no grain.’”
What makes grain-free foods different from other holistic foods is their higher inclusion of meat protein, their non-grain carbohydrate and, in some formulas, their exotic meat sources. These foods are not just slightly modified holistic foods. In fact, a pet food doesn’t even have to be holistic to be grain-free.
Unique Nutritional Features
Many grain-free diets offer a combination of these three unique nutritional features.
Most grain-free foods are higher in protein than standard dry pet foods. In addition, a very high percentage of that protein is derived from meat sources rather than plant sources. Many of the foods have claims related to how much of the protein comes from meat. I have been asked if the higher protein content is detrimental to the pet over the long term. The answer is no. It is the minerals, sodium and phosphorus that can cause kidneys to wear out, not the protein. High protein is harmful to pets with kidney failure, but protein doesn’t cause the kidney failure.
There can be concern over the ash content in some grain-free foods. Not all the meat sources used in these foods are necessarily low in bone, and with higher bone content comes a higher level of ash. This can lead to foods with higher levels of calcium and phosphorus, and they may also contain higher levels of sodium and magnesium.
Are higher ash levels harmful? The biggest nutritional concern is kidney health. Unfortunately few of these foods include the ash level as part of the guaranteed analysis or nutrient profile they provide. Some may include the calcium, phosphorus, and/or sodium level. In the chart provided I have had to use a calculated (estimated) ash level in many cases which may be slightly off the actual level. For senior pets, I recommend ash levels lowers than 8.5% for a dog food, and 6.5% for a cat food, so you may need to contact manufacturers directly to find a food with ash levels in the appropriate range.
Fortunately most of the cat foods do list the magnesium content so we do know these foods have at least that feature to help prevent struvite crystals in cats, as most cat foods do.
A number of the grain-free diets are based on a more unique meat source, such as buffalo, duck or venison. This approach is used in grain-free and traditional diets to help provide relief from sensitivities or allergies to common proteins such as chicken or beef.
Many grain-free diets with unique proteins make reference to being ‘Ancestral’ or ‘Wild Diets.’ These foods are marketed as the way the nutrition used to be, in the ‘wild’ before commercial foods and domestication of animals as pets. It’s important to note though, while most Wild Diets are grain-free, there are exceptions.
There is no question that animal or pet diets, like human diets, have changed dramatically from the diets on which our ancestors evolved. The question which I can’t answer is, “Which parts of the traditional ancestral diets were better than the present diets?” More importantly, I can’t accurately identify “Which, if any, of today’s nutritional ailments are caused by the change from our ancestral diets?” At the present time, there is little or no scientific evidence as to why these foods should have health advantages for pets. That said, one of the principles of holistic nutrition is ‘current science does not have all the answers,’ and therefore science should not be the only basis for designing pet foods.
Factors in our present-day diets that are different from our ancestral diets (both human and pet) are: more carbohydrates, more sugars, more refined/fractioned ingredients, more processed ingredients, more unsaturated fats high in omega-6 fatty acids, less fiber, and (with the exception of cats) less fruits and vegetables. Grain-free foods, including Wild Diets and other holistic foods, address the consumption of refined and processed foods, the balance of fatty acids, and the consumption of fruits and vegetables.
Most, but not all of the grain-free foods emphasize that they are low in carbohydrates. Since carbohydrate is one of the three energy sources in the food, (the other two are fat and protein), it is not surprising that the foods with the highest levels of fat and protein are the ones lowest in carbohydrate.
It’s important to note that the lower carb/higher protein levels of many grain-free foods make them higher in calories per cup than holistic or super-premium foods. If you are feeding your pet a grain-free diet, you should monitor your pet’s consumption to avoid weight gain.
When to Choose Grain-Free
Grain-free diets are a great choice if you are unhappy with your pet’s current choice of food. If your pet is not thriving on his current food, whether he has a dull coat or is less energetic, a switch to a grain-free food may be enough of a dietary change to see positive results. This is because grain-free foods are different from holistic and super-premium dry foods. A food with a unique formulation gives your pet a new start. However, unlike a scientific or veterinarian food which is formulated to treat a specific ailment, the exact nutritional reason to feed grain-free food is not as obvious. While good results from a grain-free food do not automatically indicate a food allergy, animals may be developing sensitivities to grains after a lifetime of eating traditional foods. Grain-free foods aren’t a panacea for all problems, but they are the logical next choice when a pet’s present food does not give satisfactory results.
Transition from Raw
The high meat protein, low carbohydrate grain-free foods are ideal if your pet is transitioning from a raw or high meat diet, because these foods are the dry foods with the closest nutritional profile to raw or high meat diets. Certainly if your pet needs a gluten-free diet, grain-free foods are also the answer. However, this is a very small percentage of the total pet population.
Although grain-free foods are not like the classic hypoallergenic diet, which has a very limited number of protein sources, the major protein source of grain-free foods is often very unique. This is especially true of the ‘Wild Diets.’ And by definition grain-free foods do not contain any of the grain protein in other pet foods. The change in the major meat proteins and having no grain protein may be enough for the pet to overcome a food allergy or general digestive ailment. For diagnosed, specific ingredient allergies, a classic hypoallergenic diet is probably a better choice.
Diabetic pets can also benefit from grain-free diets, but only if the carbohydrate levels are in the desired range of less than 20%.
Overall, grain-free pet foods are a both a useful, unique diet for pets that need something different, and a hot trend in the pet industry. There is a lot of variation between foods in this category, so you have many options when you are searching for high protein or low carb diets, or simply a new protein source. The philosophy of each grain-free brand is unique. To make informed and effective recommendations, you need to read the bags, the brochures and visit websites if you can.
I initially studied this category when I was looking for low carbohydrate foods for diabetic pets. One of the main nutritional features needed for diabetic pets is a low carbohydrate food. However, it quickly became apparent that although grain-free foods being generally lower in carbohydrate, they are not all potential diabetic diets. To be appropriate as a diabetic food, the calories from carbohydrates should be less than 20%. Only a portion of grain-free foods can be found within that range. Grain-free diets do not claim to be diabetic diets.