Dog parents everywhere are becoming more intentional about what goes into their dogs' bowls, and for good reason. Just as fresh, whole foods are linked to better health outcomes in humans, dog lovers are asking whether the same could be true for dogs. That curiosity, combined with advances in nutrition and shifts in consumer expectations, has fueled rapid growth in the fresh and minimally processed pet food space.

At Ollie, we believe that fresh food can help dogs live healthier, happier lives. But because this category is still relatively new, the scientific research is only just beginning to catch up. This paper takes a closer look at emerging studies that explore the benefits of fresh food feeding for dogs, from digestibility and microbiome health to energy utilization and more. It also outlines where more research is needed and how Ollie is committed to driving it forward to better understand the impact of fresh food on long-term canine health and wellbeing.

Improved Digestibility and Nutrient Utilization

Fresh and human-grade diets have consistently demonstrated superior digestibility compared to traditional extruded kibble. In a crossover study by Algya et al. (2018), dogs fed roasted, high-moisture, or raw diets showed significantly higher apparent total tract digestibility (ATTD) of crude protein and fat, with lower fecal dry matter and improved nutrient absorption. Similarly, Do et al. (2021) reported greater digestibility of energy, protein, and fat in dogs fed a human-grade fresh diet versus those on kibble.

Shifts in Fecal Microbiota 
Diet significantly influences the canine gut microbiome. Geary et al. (2022) demonstrated that dogs fed a mildly cooked human-grade diet exhibited dramatic shifts in their fecal microbiota, including increases in specific bacterial genera and metabolic pathways associated with health. The same diet also decreased fecal pH and dry matter, suggesting a favorable gut environment. Lin et al. (2022) further confirmed the microbiome-altering effects of fresh diets over time.

Skin and Coat Health, Inflammatory Markers

Geary et al. (2022) found that mildly cooked diets may have a positive influence on skin hydration and coat quality, although the effects were modest in the short term. The same study also noted increased gene expression of markers related to antioxidant activity (SOD) and inflammation (COX-2, TNF-α), indicating a potential for dietary modulation of immune responses.

Weight Management and Energy Utilization 

Roberts et al. (2023) showed that dogs fed a whole-food-based diet had lower metabolizable energy requirements than dogs on traditional kibble, suggesting better energy utilization and potential implications for weight management. Fresh-fed dogs also showed more stable serum markers and healthier body composition.

While promising, existing studies face several limitations:

• Short durations: Most trials range from 4 to 12 weeks, which limits our understanding of the long-term impacts.

• Small sample sizes: Studies typically involve 8 to 20 dogs, reducing statistical power.

• Single-breed or homogeneous groups: Many trials use Beagles or other uniform groups, which limits generalizability.

Variability in diets tested: Different "fresh" or "human-grade" diets vary in formulation and processing, making cross-study comparisons difficult.

To fully understand the long-term health outcomes of fresh feeding, the following areas need further investigation:

• Longitudinal studies: Multi-month or multi-year research to evaluate effects on longevity, chronic disease risk, and quality of life.

• Expanded biomarkers: Inclusion of oxidative stress, immune response, endocrine function, and inflammatory markers.

• Breed- and life stage-specific studies: Testing effects on puppies, seniors, and different breed sizes.

• Comparative processing studies: Controlled evaluation of how extrusion, light cooking, and raw formulations influence nutrient retention and physiological outcomes.

• Real-world efficacy: Conducting studies outside of the clinical setting to capture outcomes under everyday feeding conditions. This can help build a more comprehensive understanding of the long-term health impacts of feeding fresh food to dogs.