The Science Behind JustFoodForDogs: What a Peer-Reviewed Study Found
Our food has been studied by independent researchers. Two JustFoodForDogs recipes were named in a peer-reviewed study at the University of Illinois at Urbana-Champaign. Here’s what they found — and what it means.
PUBLISHED IN THE JOURNAL OF ANIMAL SCIENCE
JFFD RECIPES STUDIED BY NAME
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
DOGS USED OVER 28 DAYS
THE RESEARCH
A peer-reviewed study at the University of Illinois put our food to the test
In 2021, researchers from the Department of Animal Sciences at the University of Illinois at Urbana-Champaign published a study examining how different types of commercial dog food are absorbed and processed by dogs. The study included four diets — an extruded kibble, a fresh food, and two human-grade diets.
The human-grade foods tested were JustFoodForDogs Beef and Russet Potato Recipe and JustFoodForDogs Chicken and White Rice Recipe — both identified by name throughout the published research.
The study was published in the Journal of Animal Science, a leading peer-reviewed scientific journal.
PEER-REVIEWED · OPEN ACCESS
Journal of Animal Science · Vol. 99(2) · February 2021
Nutrient digestibility and fecal characteristics, microbiota, and metabolites in dogs fed human-grade foods
Authors: Do S, Phungviwatnikul T, de Godoy MRC, Swanson KS
University of Illinois at Urbana-Champaign
A controlled study using a replicated 4×4 Latin square design in 12 dogs, comparing apparent total tract digestibility (ATTD), fecal output and characteristics, gut microbiota composition, serum metabolites, and hematology across four commercially available diets — including two JustFoodForDogs recipes.
KEY FINDINGS
What the study found
These are the researchers’ published conclusions.
2-2.9 X
LESS FECAL OUTPUT
Do et al., J Anim Sci, 2021
41%
LESS FECAL OUTPUT
Do et al., J Anim Sci, 2021
Higher
ATTD VS. KIBBLE & FRESH
Do et al., J Anim Sci, 2021
Distinct
MICROBIOTA PROFILE
Do et al., J Anim Sci, 2021
The results demonstrate that by feeding pets fresh, high-quality ingredients, less waste goes in and less waste goes out.
STUDY DESIGN
What the researchers measured
Six biological markers were tracked across a 28-day period per diet. Here’s what each one means in plain language.
1
Apparent Total Tract Digestibility (ATTD)
The percentage of a given nutrient — dry matter, protein, fat, energy — that a dog’s body absorbs rather than excretes. ATTD is the core measure of food quality in animal nutrition science. Higher ATTD means more of what a dog eats is available to the body.
2
Fecal output & Characteristics
How much waste dogs produced by weight, and the quality of that stool. Because undigested food becomes waste, fecal output is a direct measure of how much of a diet is actually absorbed — less output reflects greater digestibility.
3
Gut microbiota composition
The community of bacteria living in a dog’s digestive tract. Researchers analyzed fecal samples to identify which bacterial populations were present and in what proportions. Different diets were associated with meaningfully different microbial profiles.
4
Fecal metabolites
Compounds produced during digestion, measured in stool. They give researchers a window into how different macronutrients — protein, fat, carbohydrates — are being broken down and processed throughout digestion.
5
Serum metabolites
Nutrients absorbed into blood circulation. Researchers measured these to understand the downstream effects of each diet on dogs’ blood chemistry across the controlled study period.
6
Hemoatology
A standard blood panel — red and white blood cell counts and related markers — measured in all dogs to monitor overall status throughout each dietary trial period.
"In conclusion, the [human-grade] pet foods tested resulted in significantly reduced fecal output, were highly digestible, maintained fecal characteristics, serum chemistry, and hematology, and modified the fecal microbiota of dogs."
COMMON QUESTIONS
Questions pet parents ask about this study and what it means.
Who was this study conducted by?
This study was conducted independently by researchers at the University of Illinois at Urbana-Champaign Department of Animal Sciences and the Division of Nutritional Sciences. The study was published in the peer-reviewed Journal of Animal Science in 2021 and is freely available via PubMed Central.
What is nutrient digestibility, and why does it matter?
Nutrient digestibility measures how much of a food’s nutrients a dog’s body can actually absorb and use. It’s expressed as apparent total tract digestibility (ATTD) — the percentage of a given nutrient that doesn’t end up as waste. In animal nutrition science, ATTD is a foundational measure of food quality. A highly digestible food means more of what a dog eats is available to the body; a less digestible food means more is passed as stool.
What does "human-grade" legally mean?
Human-grade is a legally defined term regulated by AAFCO (the Association of American Feed Control Officials). For a pet food to be called human-grade, every single ingredient must be human edible, and the product must be manufactured, packed, and held in accordance with federal regulations for human food. Most commercial pet foods do not meet this standard. JustFoodForDogs recipes are made of USDA-inspected ingredients and meet this definition.
Which specific JFFD recipes were in this study?
The two JustFoodForDogs recipes included in the University of Illinois study were the Beef and Russet Potato Recipe and the Chicken and White Rice Recipe. Both were identified by name throughout the published study as the human-grade diets under evaluation.
What is the canine gut microbiome, and what did the study find?
The gut microbiome is the community of microorganisms — primarily bacteria — living in a dog’s digestive tract. Diet is one of the primary factors shaping microbiome composition. Researchers analyzed fecal samples and found that dogs fed human-grade and fresh diets had microbial communities that were markedly different from those consuming extruded diets. The researchers attributed this to differences in ingredients, nutrients, and processing methods across the diets.
LEARN MORE
Understand the science
Plain-language guides to the concepts behind this research.
CITATION
Sungho Do, Thunyaporn Phungviwatnikul, Maria R C de Godoy, Kelly S Swanson, Nutrient digestibility and fecal characteristics, microbiota, and metabolites in dogs fed human-grade foods, Journal of Animal Science, Volume 99, Issue 2, February 2021, skab028, https://pubmed.ncbi.nlm.nih.gov/33511410/
The research referenced on this page was conducted independently by university researchers. This content is educational only. Consult your veterinarian for guidance specific to your dog’s health needs.