Kibble vs. Nom Nom — Who’s More Digestible?
Your pet’s food is absolutely nothing to kibble about, and the Nom Nom R&D team set out to prove it once and for all. For the first time ever, the team — led by Dr. Justin Shmalberg — pitted Nom Nom fresh food against dry kibble in a head-to-tail measurement of digestibility.
Why does digestibility matter?
It’s all about the nutrients. Like humans, pets don’t always 100% digest the food they consume. Which means there are vitamins and nutrients that don’t get absorbed, and go to waste. A diet with higher digestibility simply means that higher amounts of healthy nutrients can be utilized for growth and maintenance.
Digestibility is determined by many factors, like the amount of fibers in the food or the degree of cooking. And there has been some evidence showing that freshly cooked pet food is more digestible than kibble.
That’s what we set out to test.
How do you test digestibility?
To put it scientifically, we looked at fecal matter. Yes, pet owners, what’s going on with their poo is very important and can be an indicator of food digestibility.
Back to the study
A randomly selected group of dogs were fed an all-kibble diet for 10 days and then switched to Nom Nom Chicken Chow for another 10 days. From a portioning perspective, each dog was free-fed, allowing them to intake as much of each food type as they wanted.
During the experiment, their food intake and fecal weight were recorded. At the end of the study, their fecal samples were sent to a lab for an analysis of nutrient composition. (We love our jobs.)
Fecal weight and frequency
Our scientists first looked at the food intake and the fecal output. Because their food intake was recorded, we know that each dog ate a comparable amount of food and calories between the two diets.
What we found in their fecal output told a different story. Shown in the chart below, the dogs defecated both a smaller amount (left) and less frequently (right) when they were eating Nom Nom compared to kibble, shown by their daily fecal weight. These findings indicate that Nom Nom is more digestible.
This is relatively straightforward: we know how many nutrients and calories the dogs ate, and we can measure how much of the same came out in the stool. The difference between these two values show the amount of nutrients and calories that were digested and absorbed. The higher the nutrients and calories absorbed, the higher the digestibility of the food source.
We evaluated the stool on four categories: dry matter (everything except water content), protein, fat and calories. Shown in the chart below, we found higher levels of all four in the fecal matter during the time the dogs were fed Nom Nom.
More digestible = more energy
Another important measure is metabolizable energy. Metabolizable energy is defined as how much energy can be utilized for growth, maintenance and physical activity per gram of food (dry weight) consumed. What we found, showcased in the figure below, was that 1 gram of Nom Nom offered 1.25 kcal more of this energy than kibble. So, for the same amount of food, your pet gets more energy to utilize toward body functions and fun.
One might think that a higher metabolizable energy may lead to obesity, since a higher percentage of calories are available to burn. However this study showed significantly less weight gain while the dogs were fed Nom Nom.
It may be because these dogs were more physically active when they were fed Nom Nom as it has been anecdotally reported. (Some findings in cats also support this notion.) Unfortunately, this study did not have a measure of physical activity and it is something that our scientists are actively investigating in a different study. (More on that soon.)
Nom Nom has a higher impact on health than kibble
Based on the lower fecal weight and frequency, higher nutrient levels in stool and greater metabolizable energy, we can say that Nom Nom is more digestible than kibble. So for the same amount of food, more energy is available and less nutrients go to waste — better supporting your dog’s growth and maintenance.
For dog parents who are statisticians, it should be mentioned that all measures demonstrated here are statistically significant (p<0.01). Also, please note that we were fair and chose a high-quality and nutrient-rich kibble for comparison. We didn’t want to win on a technicality.