Cats, carbohydrates, and science

Current published evidence thus does not support a direct role for diet in general, or carbohydrates in particular, on disease risk in domestic cats. However, available evidence does suggest that environmental and developmental factors may play a larger role in the development of chronic disease in cats than previously appreciated. If so, it may explain the focus on dry foods, which are very commonly fed to indoor-housed cats, and so might be expected to co-vary with other factors.

--article from The Canadian Veterinary Journal:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2387258/

Excess calories, regardless of source, contribute to obesity and obesity-related problems, but low-carbohydrate, high-fat diets pose a greater risk for obesity. The increasing prevalence of feline diabetes appears to be due to obesity and aging rather than to dietary carbohydrates.

--abstract from The Compendium on Continuing Education for the Practising Veterinarian:

http://www.ncbi.nlm.nih.gov/pubmed/20473847

It seems to be generally accepted as fact on this forum that carbohydrates, especially from grains, are bad for cats. That was one of the prevailing modes of thought here about five years ago when I first came across this site as a relatively inexperienced young cat owner. I clicked on the links people posted and read the information about carbohydrates in cat food basically being good for nothing but causing diabetes. And I believed it, because it really does make a lot of sense: cats are obligate carnivores, so what business do we have feeding them grains and other plant material? You don't feed dead animals to rabbits and horses, and you don't feed dead plants to a cat. So, in a rush to stop poisoning my cats, I switched to feeding them expensive, grain-free, high-protein/fat, low-carb foods.

For two years now, I've been in college, learning to be a scientist. Important to scientists in any field is the ability to question what we think we know and to adapt our knowledge to what is better-supported by research and evidence. I realized recently that I had just spent five years simply accepting as true my knowledge of cat nutrition without questioning it beyond the curiosity that kept me reading the information on someone's personal site that had been linked from this forum.

I decided to do some research into the topic and ended up finding the two publications in the above links. If they had confirmed what I thought I knew, I would not be posting here. They don't say that meat doesn't matter and that we should all start loading our cats up on carbohydrates, but they make it clear that carbohydrates are not the cat toxins they are made out to be, and that the combination of total caloric intake and lifestyle are much better predictors of cat health.

tl;dr--

So what's my point? I'm not here to tell anyone to switch cat foods if their cats are healthy and happy; however, I think it is good to be informed and aware of the current research. What that research says is that it doesn't matter much to the house cat population in general whether cats are fed a premium grain-free, low-carb food or a food that does contain grains or other carbohydrate sources; it is much more important that cats are not overfed and under-stimulated.

Well, it's not quite that simple. There are indications there is a "carb threshold" in cats. They also can't downregulate protein metabolism - so putting those two together, and the source of protein IS important for cats. The issue with grain-free foods isn't only carb content. In fact, many grain-free foods are loaded with alternate carbs. The issue is protein-source, not just "carb content," IMO.

Here is some further reading for you:

Zoran DL. 2002. "The carnivore connection to nutrition in cats," J Am Vet Med Assoc. 2002 Dec 1;221(11):1559-67. http://www.ncbi.nlm.nih.gov/pubmed/12479324 The full PDF of the article is hosted here: http://www.catinfo.org/docs/DrZoran.pdf

This piece was updated for more current research (co-authored with the same person to which you provided a link):

Zoran & Buffington 2011. "Effects of nutrition choices and lifestyle changes on the well-being of cats, a carnivore that has moved indoors," JAVMA, Vol 239, No. 5, September 1, 2011; 596-606. http://brf.vpweb.com/upload/JAVMA 2011 Nutrition choices - indoor cats.pdf

Basic feline nutritional needs: Morris, JG 2002. "Idiosyncratic nutrient requirements of cats appear to be diet-induced evolutionary adaptations," Nutrition Research Reviews / Volume 15 / Issue 01 / June 2002, pp 153-168. http://journals.cambridge.org/actio...7588&fulltextType=RA&fileId=S0954422402000070 (One of the pieces referenced in your Buffington link)

As re: the fat makes cats fat, I don't see this piece referenced in the Canadian Veterinary Journal piece by Buffington: Backus et al. 2007. "Gonadectomy and high dietary fat but not high dietary carbohydrate induce gains in body weight and fat of domestic cats," British Journal of Nutrition / Volume 98 / Issue 03 / September 2007, pp 641-650. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=1304744

As re: protein metabolism in cats:

Dr. Mark Peterson, small animal veterinary endocrinologist

"Can Increasing the Amount of Fat or Carbohydrate in a Cat's Diet Compensate for Low Protein Intake?" http://endocrinevet.blogspot.no/sea...0-05:00&max-results=20&start=14&by-date=false

As re: appropriate macronutrient content and indications there may be a carb threshold in cats: Hewson-Hughes et al. 2011. "Geometric analysis of macronutrient selection in the adult domestic cat, Felis catus," J Exp Biol 214, 1039-1051. http://jeb.biologists.org/content/214/6/1039.full#R22

And confirming the Waltham (Hewson-Hughes study) as re: macronutrient composition, an analysis of feral cat diets: Plantinga et al. 2011. "Estimation of the dietary nutrient profile of free-roaming feral cats: possible implications for nutrition of domestic cats," British Journal of Nutrition / Volume 106 / Supplement S1 / October 2011, pp S35-S48. http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8404219

Cataphyll said:

So what's my point? I'm not here to tell anyone to switch cat foods if their cats are healthy and happy; however, I think it is good to be informed and aware of the current research. What that research says is that it doesn't matter much to the house cat population in general whether cats are fed a premium grain-free, low-carb food or a food that does contain grains or other carbohydrate sources; it is much more important that cats are not overfed and under-stimulated.

Click to expand...

I don't disagree with you at all. This is true for any species, really: maintain an ideal weight and get lots of exercise. Common sense, really.

Dogs and humans have 5 different systems for metabolising carbohydrates. Cats have just one (Dr. Elizabeth Hodgkins 2008. "Your Cat: Simple New Secrets to a Longer, Stronger Life," St. Martin's Griffin; 1st edition (October 14, 2008). (Dr. Hodgkins is one of the U.S. leading experts on feline diabetes).

Their natural diet is very low carb as you can see from the Plantinga study: just 2.8% on a dry matter basis. And their natural protein source - as obligate carnivores - is meat, not plant-based proteins. So why feed our obligate carnivores something their systems weren't really meant to process in any volume? :dk:

If you want to peruse a list of diseases in cats that have been linked to diet, this is an interesting summary:

http://www.mousabilities.com/nutrition/research.html

IMO, the issue with cats and disease is likely not to be "just" the carbs, or even primarily the carbs, but the (lack of quality in) ingredients in commercial cat foods in general (and if you want to do some reading on that, here's a well-referenced piece: http://leda.law.harvard.edu/leda/data/784/Patrick06.html). When I suggest to people that they consider a grain-free food, it's principally due to the protein-source consideration - though I do also recommend people look for low-carb foods (because grain-free isn't by definition low-carb), just because it's what our cats naturally eat - what their bodies are designed to metabolise.

Let's face it: a human eating dry cereal, day-in, day-out isn't likely to be healthy when they're older, either. Add some canned stew, and maybe they'll do better. But we already know that fresh foods are better for humans. Why wouldn't that be true for our pets as well? :dk:
.

LDG, I appreciate your thorough reply, especially the links to the Zoran and Zoran/Buffington articles--all I could find of those in my search were the titles, not even the abstracts--and the Peterson blog. My knowledge and understanding of organic and biochemistry is pretty slim but other than having to wade through some parts, I think understood more than enough out of the articles to cause myself to stop and think that perhaps I jumped the gun here.

What I really got out of them is a better understanding of how and why animal proteins are important for cats, especially aging cats. I of course wasn't trying to convince anyone that premium cat foods are useless except to make the cat owner feel better, but even though I presented an oversimplified version the issue in my first post, reading your links doesn't completely sway me back.

I agree that the diet that cats evolved to digest is best for them and we should try to approximate that as best we can for our own cats, but I remember back when I first started reading into cat nutrition and looking for higher-quality foods. I had almost no money at the time and was worried that if I didn't buy the absolute best cat food I could afford, I would be poisoning my cats. Consequently, my cats ended up eating significantly better than I for a while, and I subsisted on PBJ and 75-cent microwaveable frozen pizzas from Bi-Lo. Having read the articles I've read today, I probably would have come to the conclusion that it would have been perfectly acceptable for the cats and I to compromise and all eat moderately healthy foods.

Oh absolutely. :nod: There's no need to break the bank on cat food. The commercial cat foods are full of marketing ploys, and it's easy to buy-into them. :nod: In the end, there is very little difference between a canned cat food with "chicken" as the main ingredient, whether it costs $0.50 a can or $2.00 a can. I recommend Friskie's pate foods and Fancy Feast classics foods to people on a budget all the time. Yes, most of the Friskie's pate foods have rice in there; almost all of them have meat by-products as the main protein source (except Poultry Platter, which does have chicken as the main ingredient, go figure. :lol3: ).

There's no need to shell out for the more expensive canned foods like EVO or Nature's Variety if your cat doesn't have any food-related sensitivities and need a limited ingredient or single-source protein diet. Both have a VERY high fat content (mschauer did an analysis, it's posted in the thread for her former foster kitty, Micky's weight loss program: http://www.thecatsite.com/t/245236/mickey-my-27-lbs-foster-and-his-journey-back-to-a-healthy-weight ). When you get a chance, read the piece by Patrick, written in 2006 (the one hosted at the Harvard Law website). What "chicken" means in a cat food doesn't guarantee your cat is getting much in the way of MEAT from chicken anyway. Certainly not the juicy chicken breasts we imagine. So from that standpoint, there's very little difference between most premium brands and inexpensive alternatives. There are grain-free, low carb options where most of the protein comes from an animal, anyway, that don't cost an arm-and-a-leg.

In fact, Dr. Pierson spent a great deal of time putting together a list, comparing the macronutrient content of cat foods. It's based on the average nutritional analysis as provided by the companies (and if companies didn't provide it, it's not included in the list), rather than the guaranteed analysis, so it's far more accurate than anything we could calculate on our own. It makes it quite easy to identify high protein / low carb foods. From there, it's up to individuals to evaluate the cost and ingredients. But it's surprising to find so many affordable foods on there that aren't loaded with grains or veggies. http://www.catinfo.org/?link=cannedfoods The link is in that discussion.

cataphyll said:

...I had almost no money at the time and was worried that if I didn't buy the absolute best cat food I could afford, I would be poisoning my cats.

Click to expand...

I just wanted to add . It's really confusing, that definition of "absolute best." :nod: A moderate amount of carbs probably isn't going to hurt a cat. Moderation in everything, as the saying goes...

It can be very difficult to wade through the huge amount of information available on the internet - much of it conflicting - and figure out what is "best."

If, after some research, one comes to the conclusion that meat-based proteins and a diet that resembles their natural one is best, it makes it a heck of a lot easier to wade through cat food options and ignore the advertising.

I make my own cat food a) because I decided the quality of most commercial cat food ingredients isn't "best" to begin with - and it's all highly processed, and b) it costs less than a non-kibble commercial diet. I buy some relatively expensive stuff to feed my cats (like venison, lamb and rabbit - AND have a number of things shipped to me frozen), and it still works out to $0.97 per cat per day.

There's a college student (peaches08) who invested in a food grinder that can grind bones so she could make the recipe posted by Dr. Pierson on her website (http://www.catinfo.org). The payback was just 8 months, and it costs her less to make her own food than buy any canned cat food. If I eliminate the more expensive things from the diet I feed my cats, it would cost me $0.50 a day per cat. And then they really do get human-grade meat as part of their diet, because I'm buying the same things for them I would for myself. :lol3: (Though I HATE liver and won't eat kidney!)

its interesting to read about other cat owners experience that drive them to how the care for their pets.  I am a recently evangelized raw feeder, and I make the food myself as well.  Its funny how I came into it.  I had cats (like you cataphyll) as a young person in college, I got ittens with my girlfriend.  We loved those cats, but didnt really do the homework that we should have, this was over 10 yrs ago.  I fed them kibble, gave them a single litterbox that didnt get changed enough, and got them declawed.  I did these things because I dint know better, I thought it was what you were supposed to do.  I sure did love those cats though, they were our kids.  The gf turned into wife, and then ex-wife, but those cats were always there for me.  Although my boy was overweight and had teeth rotting out of his mouth, and my female lost teeth and had a growth on her mammary.  Loving them did not keep them healthy.  Then, many years later I had a tragedy at home and they both passed away....this was less than 1 yr ago.

After some time to grieve, I decided to get new kittens and start over, but this time I am older, wiser, have sufficient finances, and a desire to not only love them, but do everything for them that I neglected to do right for my old cats.  Just a desire, mind you, no knowledge or plan.

My new beautiful kittens were purchased, and I fell in love all over again with them.  I got the 'good stuff' EVO Innova dry food, reccomended by the breeder...obligate carnivores she said (1st time I heard that word)...but I listened and bought what I was told.  Then the Innova was recalled for Salmonella contamination, and I had to switch to another expensive brand, Blue Buffalo.  Well with the switch, my new male got diarrhea, and the vet suggested boiling chicken breast and feeding it to him.  But not only did it cure the diarrhea, but it opened my eyes.  Looking at the cut up real meat, so fresh, appetizing, and natural....compared to the dry food...smelly, processed, pellets...I didnt need to read scientific journals to determine which is better for my cats.

I can now literally feed them anything, money is not an issue....I told myself that obviously the best food for these guys is clearly natural, home-made food with high quality ingredients.

So I googled "Home made cat food" expecting to find neat cat versions of lasagna and tuna cassarole....but the 1st link was dr. pierson's site, I gained some serious knowledge about feline nutrition.  

So for me the answer was: 1. definitely make it myself, 2. raw meat for a carnivore, duh...why did this not occurr to me before????, 3. Thats all there is to it

As a cherry on top, the cost is LESS than wet food, of course there is a capital investment with the equipment to make and store the food

And the benefit is: 1.  No more GI issues, tiny odorless poo's,   2. No more bad breath   3. Super soft fur   4. Energetic, happy, appreciative cats  5. Peace of mind that I ma giving them not only love, but the very best food that I can possibly provide.

So, to OP: I am a scientist too, well, Engineer.  My advice is: don't overthink it...we tend to do that...common sense is often all you need.  And dont believe anything in a TV commercial

Thanks for bumping this LehighLuke.

I was wondering why the leda.law link to the article on pet food regulation (Patrick 2006) wasn't working. They changed the address: http://dash.harvard.edu/bitstream/handle/1/10018997/Patrick06.html?sequence=2