Evidence Update–Homemade Diet Recipes for Your Pet are Unreliable

I have previously discussed studies of recipes for homemade diets, from books and the internet, which show that these diets are rarely nutritionally adequate or reliable in terms of consistently providing predictable levels of critical nutrients. Recipes for kidney disease, cancer diets, and raw diets have all been evaluated and found wanting. Now the largest study yet looking at the nutritional adequacy of homemade diet recipes has been published and—surprise, surprise—it has found that almost none of the recipes evaluated provide recommended levels of important nutrients.

Stockman, J. Fascetti, AJ. Kass, PH. Larsen,JA. Evaluation of recipes of home-prepared maintenance diets for dogs. Journal of the American Veterinary Medical Association. 2013;242(11): 1500-1505.

Two-hundred  recipes were evaluated, including 129 written by veterinarians. The vast majority were vague about ingredients, feeding instructions, or the details of recommended supplements. Only 5 recipes could be interpreted as providing adequate levels of all essential nutrients as established by the National research Council guidelines, and only 9 recipes met the nutrient standards of the Association of American Feed Control Officials (AAFCO).

Despite common claims that nutritional adequacy can be met by rotating through a variety of foods even if no specific recipe is complete in itself, the authors found that when such groups of recipes were evaluated, they still did not provide a nutritionally complete diet even when fed in rotation as directed. Even though most recipes written by veterinarians were incomplete, those recipes provided by non-veterinarians were significantly more likely to be incomplete and were more likely to have more severe deficiencies. All 4 recipes written by board-certified veterinary nutritionists were complete. This pretty clearly demonstrates that claims veterinarians are not better qualified than lay people to make nutritional recommendations are nonsense. The best source of advice about pet diets is a veterinary nutritionist, and the second best source is your veterinarian.




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30 Responses to Evidence Update–Homemade Diet Recipes for Your Pet are Unreliable

  1. Stacey says:

    I get so tired of hearing that I am not intelligent enough to formulate a diet for my dog because I am not an “expert.” The NRC numbers are readily available. The USDA website lists the profiles of many, many foods, raw, cooked, ect. It’s really not that difficult to put everything into a spreadsheet so it’s complete and balanced.

  2. skeptvet says:

    Seems like it shouldn’t be, but then why do all these recipes fail?

  3. Stacey says:

    I assume most people are too lazy for math, research, and spreadsheets.

    The ironic thing is that many of the inadequate diets would probably pass the AAFCO feeding trial standards in an informal way. (A total of 6 dogs eating a food for 6 months with good blood results before and after and without losing more than 15% body-weight.)

    I have a difficult time taking nutrition advice from a vet pushing a very expensive food like ScienceDiet that has a vitamin/mineral pre-mix that is inferior to what is used in Dog Chow and Pedigree.

  4. v.t. says:

    I get tired of raw foodists using the (hey, Skeptvet, can we call it the Science Diet, or “Big Three gambit”?) excuse that because a vet carries, promotes or uses a product, he must be an idiot in animal biology and nutritional needs of his/her patients. Reality check: you don’t have to buy the product!

    The average pet owner may not have a clue how to provide nutritious meals for themselves, but suddenly they are the experts in home-made meals for their pets, based on…what, google university and spreadsheets, that were already so-called “developed” by another clueless owner or wannabe vet nutritionist/maufacturer before you?

    Sorry to sound harsh, but that seems more likely.

  5. Stacey says:

    If a vet cannot or will not put the effort into selling a higher quality food, what else are they not putting the effort into that they should?

    And if you think the NRC and the USDAA are clueless, wannabe, vet/nutritionists and/or manufacturers, I can’t help you.

  6. v.t. says:

    So, a vet sells dog and cat food, vitamins, shampoo, treats, supplements, toys, leashes and collars – having a retail area makes the vet incompetent?

    What do you consider a high quality food that the vet should sell in his/her clinic? Name only one or two, as vets often choose not to carry more than a couple products due to limited space.

  7. Art says:

    Stacy, if you have a homemade recipe for treating hyperthyroid cats please post it.
    Art Malernee Dvm

  8. Murray Webb says:

    It’s just NOT that difficult to feed dogs homemade meals. What do you think the great majority of people did prior to the invention of dry foods?

    Also, I figure that people manage to feed their own damn kids with minimal adverse events, formal training, or input from medical professionals/manufacturers of kiddy kibble. Reading a few books on raw feeding/homemade diets gives the intelligent pet owner the opportunity to safely and effectively feed their animals.

  9. v.t. says:

    Murray Webb,

    Before the invention of commercial dog food, people fed table scraps or cuts of various meats, or who knows what. None of which was actually nutritious, balanced properly or fortified with essential vitamins and minerals. Just like humans, pets back then also suffered various illness and died young.

    Reading books about raw food does not make an educated pet parent. In fact, such content in these books are fraught with problems and lack of evidence to the claims of their authors. Safely and effectively? Not any more so than those evil “kiddy kibble” you speak of, and sometimes, the risks are greater.

  10. skeptvet says:

    Sure, people “can” feed anything they like, to their pets or their kids. Whether or not they “should” is a different question. Nutrition has many impacts on health, and the evidence is clear that traditional nutritional practices not informed by scientific evidence are often inadequate. Scurvy went away once we discovered what caused it and changed feeding practices that were widely used but ineffective.

    What matters is whether or not there is evidence that feeding whatever you happen to think is bets, or whatever you happen to have around, is as good or better than feedinga commercial diet. There is no reason to think it is better, and some good reason to believe these kinds of homemade diets are inferior and unhealthy. Just because people did, or do feed this way doesn’t mean it is healthy. You might want to consider the rise in the prevalence of childhood obesity and diabetes, for example, before you suggest that how we feed our kids is evidence that haphazard homemade diets are good for our pets.

  11. saynotokibble says:

    Best PR campaign strategy ever!

    Partner with a major university; create your own proprietary measuring tool, measure competitors to your standards instead of the well accepted Gold Standard, then publish in a major journal like JAVMA posing as science when the research is pseudoscience at best. Sorry JAVMA, but you’ve been fooled, and are being used as a tool for publicity. These are the same tactics and pseudoscience that has been used by the same industry for too long now. It needs to end.

    One of the authors of this study is an owner of the Balance It balancing system. This is also the autobalancer used by the research team and UC Davis to make their diets. Does it seem strange to anyone else that the very researcher involved in the study, and for that matter the research team and very university, has a financial gain in finding 200+ other methods for making a homemade diet, including those of 120+ veterinarians as inferior to their own?

    From the Balance It website: “DVM Consulting, Inc. was founded in 2003 by Sean Delaney, DVM, MS, DACVN, a board certified veterinary nutritionist who held an academic faculty position at UC Davis between 2003-2013, headed R&D for Natura Pet Products, Inc. until its acquisition by Procter & Gamble”

    This “study” is essentially a Press Release from UC Davis attempting to stop people from making potentially more wholesome diets at home. Vets should be outraged that this group is trying to kill a trend toward more wholesome options instead of supporting them. It is essentially the same as a reputable human doctor fighting tooth and nail for some “Balanced Human Kibble” or processed “Human Meal Replacement Powder” against a balanced whole meal, simply because he’s part owner and his parent company is Proctor and Gamble. It wouldn’t make any sense there, and it makes no sense here.

    There are many flaws with this study including: 1) potential conflict of interest 2) novel methodology that has not been used before 3) proprietary methods 4) small sample sizes used to make very large generalizations (only 15 diets were actually prepared and lab tested, but 200+ were claimed to have been concluded on – big leap in the evidenced based process).

  12. skeptvet says:

    Potential conflicts of interest are certainly a legitimate critique, though they don’t automatically invidate anything a person publishes. Apart from pointing out the limitations in this study, which I agree should be co spidered in interpreting it, do you have any specific evidence to support your own claim that homemade diets are healthier than commerci diets? It’s a common claim, but Ive never seen it supported by anything better than theoretical and philosophical argument, never actual data.

  13. Anthro says:

    Still (patiently) awaiting your review of “Feed Your Pet Right”.

  14. Kelly Goocher says:

    I love this discussion! and SkeptVet – I love your website – for providing me a ‘skeptical’ look at the issues and helping to get my own brain working!

    I embarked on the raw/real food option for my 11 1/2 y/o dog 4 months ago. I solicited (purchased) the advice of someone who would develop a ‘diet’ for my dog that would meet the 2006 NRC standards (or so they claim – how am I to prove?). It appears that the diet may not have sufficient calories for my dog – though yet unproven. She is losing weight – but not consistently.

    SkeptVet: you state: “What matters is whether or not there is evidence that feeding whatever you happen to think is bets, or whatever you happen to have around, is as good or better than feedinga commercial diet. ” Here’s my problem with this statement. We hear more and more and more in health new for humans that ‘processed’ food is “bad” and we should eat more ‘natural’ (note single quotes) and fresh – unprocessed foods for optimum health! So why should that be any different for a DOG! “Commercial” dog food is about as processed as you can get! You take meat and vegetables and create some small, dried unrecognizable round thing and call it “food”. And chock full of artificial vitamins and minerals – as well as some very nasty garbage – in some cases. YUK!! BE SKEPTICAL when advocating for ‘commercial’ foods. Fresh meat and maybe (depending on who you ask) fresh vegetables and fruits (in small quantities) have GOT to be better than highly processed, dried kibble! Be honest!

    There’s a middle road here – Follow the nutritional guidelines out there (2006 NRC – less so the AAFCO), AND feed Real meat and real veggies/fruits/seeds – for the optimum health of your dog or cat!

    Just had to jump in here!

    Kelly and Maggie

  15. skeptvet says:

    I don’t have any objection to homemade diets, and I don’t claim that commercial diet are optimal. As I have often said, I think we know enough to avoid gross nutritional deficiencies, but we don’t have enough information to determine what is optimal. In human nutrition, guidelines, recommendations, and fads change all the time. What is “healthy” in one decade is “toxic” the next, and vice versa. So I’m a fan of taking a cautious, science-based approach to nutritional recommendations and being circumspect about how confident we are in these recommednations.

    The problem is that people take the very reasonable idea that some aspects of processing foods may have negative health effects and draw excessive generalizations, up to the extreme view that any processing, including cooking, is unhealthy. And people make equally unjustified leaps in the other direction of assuming that any unrpocessed diet is better than any commercial diet. I still maintain that the degree of scientific evidence supporting the nutritional adequacy and over health support value of commercial pet foods is far greater than the evidence available to support the haphazard feeding of fresh ingredients based on the particular intuitions or theories of individual pet owners.

    Personally, I suspect the best diet would be a fresh, homemade, cooked diet formulated by a nutritionist based on the specific needs of the individual patient, and I often recommend this. However, I recognize this is not a suspicion grounded in strong evidence, and I also know that the majority of pet owners will not go to this amount of trouble. In that case, I think commercial diets are likely better than haphazard homecooked diets that most people will actually feed, based on what they are eating or on recipes from books and the internet which we know are rarely able to meet even the minimum standards of adequacy. And extrapolating from the current theories about human nutrition doesn’t necessarily make a lot of sense. Should we feed low-fat, low-cholesterol, low-salt diets to our dogs to prevent atherosclerotic heart disease? Well, the evidence for the value of those once widely recommended diets has weakened considerably, and dogs don’t generally get that disease anyway.

    So while I think your guess about a healthy diet is reasonable, it is still just a guess, and lots of reasonable guesses in nutrition have proved mistaken before.

  16. Felicia says:

    Thank you for using (and citing) actual research in your blogs. I have been trying to find research about raw food diets for awhile and have not had any luck.

    I do have a question for you. What are the nutritional guidelines established by the AAFCO and NRC? Maybe I am not looking in the right place, but I have looked on http://www.petfood.aafco.org and can’t find any numbers.

    I wish I could read the article for myself, but I saw that you must pay to do so. Is the Journal of the American Veterinary Medical Association your main source for pet health research?

  17. skeptvet says:


    There are hundreds of veterinary research journals, and the literature on nutrition is spread among many of them, so when looking up specific topics, I refer to a lot of different journals. Unfortunately, as you can see, many of them are not yet committed to open access, so it can be difficult to retrieve and appraise original articles. I have a umber of sources, but there are still journals I can’t get access to.

    Similarly, the AAFCO and NRC guidelines are available for a fee. AAFCO sells their publications on their web site, and the NRC guielines can be found on the NAP page. It would be better if these could be freely available, but that isn’t yet the case.

    Thanks for the comment.

  18. If 4 of the recipes tested were found nutritionally complete, where would we find those? Thank you.

  19. skeptvet says:

    You could try contacting the authors of the original article.

  20. Roxy says:

    I’m sorry – but I can’t believe no one is realizing how invalid a proprietary computerized assessment of 200 diets is, based on the lab testing of only 15 recipes that were actually prepared. There was only one goal to this study – and that’s to support the decades of feeding extruded waste products to our pets. Had the goal of this study been to truly evaluate nutritional adequacy – it would have run feeding trials – the only true way to evaluate nutrition.

    We need feeding trials on homemade diets.

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  22. simba says:

    Roxy- what do you mean by ‘waste products’?

    Humans have a good history of taking the more nutritious parts of our food and throwing it away- brown rice husks, organ meats (those eyeballs and guts and testicles and things), wheat bran. All probably better for us than the bacon and polished rice and white flour that we adore, as we’re now coming to find out. Brown bread and rice, buttermilk, organ meats, corn, the cheaper sorts of vegetables were all thought of as ‘poverty food’ though- much better to eat our nutrition poor white bread.

    Don’t get me wrong, I love white bread, but ‘waste products’ implies little or nothing about nutrition and much more about cultural values.

  23. Wendy says:

    The european petfood makers club FEDIAF has the guidelines on the webs for free. http://www.fediaf.org/fileadmin/user_upload/Reports/Nutritional___Analytical_Science/Nutritional_guidelines.pdf

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  25. Kate says:

    I realize I am coming to the discussion 2 years late, but I want to add that the AAFCO and NRC guidelines are available for free on the Internet. There are tables with both sets of guidelines in this chapter: http://www.merckvetmanual.com/mvm/management_and_nutrition/nutrition_small_animals/nutritional_requirements_and_related_diseases_of_small_animals.html

  26. Virginia Stern says:

    I would have liked to have read the article cited in full rather than just the abstract. Since I follow the NRC’s guidelines, based on “computational analyses”, it would have been interesting to know what the common errors were.

  27. Sabra Ewing says:

    I was reading in another article that the common errors were not enough calcium and not enough vitamin E. If you look at most recipes on the Internet, they do not call for any type of a calcium source, and some of them only have very few ingredients like chicken and rice and they say they can be fed to your dog long term. Also, many do not specify that the meat has to be 85% lean and that you need to add your own fat to balance out the fat versus the amino acid profile. I was also reading that a lot of these recipes will cause deficiencies and minerals like zinc and manganese and copper. Even if you are doing a cooked diet, you would need to add some sort of oyster or organ me to get these. That would be the easiest way at least.

  28. art malernee dvm says:

    Single source maintance diets are a risk factor for disease. Not sure why only Paul Pion let’s pet owners know that. I guess it has something about when he found hills c/d producing heart disease that killed cats. Everyone wants you to feed the same thing which does make a nice formed stool.

  29. EDWARD COLLINS says:

    I appreciate the service you do hear sir, but did you consider the following:
    “Dr. Delaney is a Diplomate of the American College of Veterinary Nutrition and is a lecturer in clinical nutrition at the Veterinary Medical Teaching Hospital at the University of California, Davis, USA. He is also the principal consultant for Davis Veterinary Medical Consulting, which specializes in nutritional consulting for the petfood industry.”
    He consults for the pet food industry sir. Misinformation or skewed evidence occurs in both the medical and food industries for HUMANS. Some would say there is an unholy trinity between government, industry and lobbyist/consultant types like this doctor that are often to the public’s detriment while enriching those that regulate and provide info.
    I do not know if that is the case here, but Dr. Delaney has a potential conflict of interest which should not be ignored and SHOULD BE fully disclosed..

  30. skeptvet says:

    Yes, many nutritionists consult for the pet food industry, and that raises the issue of possible bias, so such connections should be disclosed. When you go to the web site for the journal to read the article, the affiliation of one of the authors with Dr. Delaney’s company is disclosed right up front. Such affiliations are one factor to consider in interpreting research data, but they don’t justify simply ignoring the evidence. The methods of the study rely on involve well-established nutritional standards and are pretty transparent.

    On the other hand, as I pointed out when responding to this question in a prior comment, where is the evidence that the study is mistaken or that home-prepared diets are healthier than kibble? In the absence of such evidence, the concerns this paper raises are still significant.

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