What is the NRC?
You may have heard about an “NRC raw diet” or about the “NRC guidelines made by the pet food industry” (some claim that these are even useless for raw fed pets). Or maybe you’ve never heard the term “NRC” at all.
Many of you requested that I cover the science of nutrition more in-depth, and many have questions like “how much supplement do I need to give my cat?”. To answer all this, I first need to explain what the NRC is, as it will be a staple for the next articles.
So, in this article, I won’t cover concepts of nutrition or how to feed your cat, but I’m going to explain what the NRC is and what it is not.
What is the NRC?
NRC stands for National Research Council, which is the operating agency of the National Academies of the USA. The National Academies are private (non-governmental) and non-profit organisms dedicated to science and technology and to their use for the general welfare. The National Research Council, being the operating arm of the National Academies, carries studies in their name to further science and to make it available to the public and scientific communities.
Now, you may ask what the NRC has to do with cat nutrition. In fact, when we talk of NRC in the raw feeding community, we aren’t directly referring to the NRC itself, but to the “Nutrient Requirements of Dogs and Cats” which is a textbook made by the NRC. As its name indicates, the Nutrient Requirements of Dogs and Cats defines the nutrient requirements of dogs and cats based on the existing science.
As of today, the latest version of the textbook was published in 2006 and it’s an updated version of the one written in 1986. The purpose of this textbook is to provide updated estimates of requirements for all nutrients, including discussions of nutrient metabolism, toxicity, deficiency, and nutritionally-related diseases in both dogs and cats.
In other words, the Nutrient Requirements of Dogs and Cats is a meta-analysis of all the scientific knowledge concerning the nutrition of dogs and cats. From this analysis, it also establishes nutritional guidelines that can be used by the pet food industry and by academia to formulate diets, or by the government to regulate pet food.
Therefore, what is often called an “NRC raw diet” is a raw diet that complies with the nutrient requirements of cats (or dogs) as defined by the “Nutrient Requirements of Dogs and Cats” book made by the NRC, in order to make sure that all the nutritional needs of a cat (or a dog) are satisfied.
From now on, for the sake of simplicity, when I write NRC I will refer to the book made by the NRC and not to the National Research Council itself.
What the NRC is not?
The NRC is not just a bunch of tables with some values defining the nutritional requirements of cats and dogs. In fact, the nutritional tables are publicly available on the internet. The NRC comprises more than 300 pages of explanation on the current state of the art in canine and feline nutrition. For each nutrient, the reasoning behind each recommendation is explained in detail and the studies that led to that conclusion are sourced.
It is important to note that the NRC is not just one big study, but an analysis of the thousands of studies available on pet nutrition. At the end of each chapter, you can find references to the hundred of studies used for writing the chapter.
The NRC is often accused to be written by the pet food industry: while it is true that, to write its book, the National Research Council received some funding from the Pet Food Institute (the main association of pet food manufacturers in the USA), it also received funding from the NIH (National Institutes of Health) and the FDA (Food and Drug Administration).
There are also restrictions on the amount of funding that the National Research Council can accept from sponsors that may have some conflicts of interest in the report.
Furthermore, as we have seen before, the NRC is a non-profit and independent organization.
Moreover, 9 out of the 10 authors are university researchers and part of academia. The last one is an independent consultant. None of them is from the pet food industry.
It is often said that the NRC is solely based on studies made by the pet food industry. This is, again, false. The NRC is based on all the available studies on feline and canine nutrition. Many (if not the majority) of them have been published by universities and researchers, independently of the pet food industry. It’s also important to note that the methodology of a study is more important than who it was funded by.
So, the NRC is not written for or by the pet food industry. It’s written by scientists in order to make the latest advances in companion animal nutrition available to all.
Finally, another argument that is often used against the NRC is that it’s based only on industrial pet food. Therefore, the recommendations would be useless for homemade diets made of fresh ingredients, as in a raw diet. While it’s true that the majority of studies are made on kibbles or purified diets (highly bioavailable and digestible diets tailored to study individual nutrient requirements) for practical reasons, the bioavailability of various ingredients is taken into account when such studies are considered. Feeding a raw or homemade diet is still feeding food that has nutritional values. Therefore, all the science of nutrition still applies to it.
Why is the NRC useful?
The NRC is one of the best and most complete resources which exists on cat nutrition.
In fact, all the other existing nutrient guidelines definitions, such as the one made by the FEDIAF (European Pet Food Industry Federation) and the AAFCO (Association of American Feed Control Officials) are based on the NRC.
However, the NRC, while being the best resource available, is not perfect.
In fact, we still don’t know everything about the science of nutrition. For some nutrients, no studies have been done yet so the recommendations are not absolute. For example, concerning the manganese requirements for cats you can read: “Because of the paucity of information, it is difficult to provide absolute recommendations for dietary Mn allowances for kittens, adult cats, or for gestation and lactation”. This is acknowledged and explained in the NRC: that’s why it’s important to know and understand where the numbers come from.
Additionally, the NRC was published in 2006. In the past 15 years, many new studies have been published and so some of the data may be outdated.
Finally, it is important to remember that the nutrient requirements are guidelines and, as such, they are not absolute rules. That’s why a big part of the work behind the formulation of a diet is to look behind the numbers, to know how to interpret them, and to adapt them for each pet.
In the end, the NRC is the best reference on cat and dog nutrition, providing a scientifically sound set of guidelines to formulate a balanced diet for our pets. However, it is not perfect and can be challenged. Before doing so, you need, however, to understand where the guidelines come from and how they were established.
Now that we know what the NRC is, I will explain in future articles how, for example, you can use the nutrient requirements to improve the diet of your cat.
Note: If you decide to buy the NRC be aware that it’s not a casual book but an academic textbook. You won’t find any examples of ready-made diets for your cats or dogs.