"The apparent total tract digestibility of DM, protein, fat, nitrogen-free extract, and calories of the kibble diet were all significantly lower than any of the fresh diets (adjusted P < 0.001 for all)."
Is fresh dog food worth it?
Fresh food has real, proven upsides and a steep price premium, but the “healthier and longer-lived” claims aren’t supported. Here’s what the evidence shows, every study graded for design and funding.
What kind of evidence is this?
Proven on digestion, unproven on health
The digestibility benefit comes from controlled feeding trials. The health and longevity claims come from industry-funded biomarker studies and owner surveys, with no randomized trial showing fresh food extends a dog’s life.
Where the evidence stands today
Fresh and gently-cooked food has one genuinely proven benefit: it’s more digestible, which means smaller, firmer stools and, like any moist food, good hydration. What it doesn’t have is controlled evidence that it makes dogs healthier or helps them live longer. Every “fresh dogs live longer” claim traces back to industry-funded biomarker studies or confounded owner surveys, and the one large survey that properly adjusted for confounders found diet barely moved owner-reported health.
What's supported
Benefits with real evidence behind them.
"[D]ogs fed the extruded diet had greater (P < 0.05) fecal output (as-is; DMB) than dogs fed fresh (1.5–1.7 times greater) or HG foods (2.0–2.9 times greater)."
Fresh food was more digestible (more of its nutrients get absorbed, leaving less waste) than extruded kibble on every macronutrient, but less so than the frozen and freeze-dried raw diets in the same trial.
What isn't
Claims the evidence doesn’t back.
"This study is the first long-term feeding study evaluating serum metabolomics in dogs that demonstrates the dramatic and sustained impact that diet can have on canine metabolism."
"[T]he study compared two foods that differed in both processing and nutrient content… In scientific terms, the variables were ‘confounded,’ or tangled together in a way that makes it impossible to know which one caused the results."
BSM Partners, 2025
An unpublished 2003 Belgian survey of about 500 dogs reported that dogs fed homemade fresh diets lived around 2.5 years longer than dogs fed industrial food. The figure was never peer-reviewed and couldn't separate diet from owner factors like income, attentiveness, and keeping the dog lean.
Lippert & Sapy, 2003 (unpublished)
"[D]iet has limited impact on owner-perceived dog health status; instead, dog age, frequency of veterinary visits and receiving medication are most important."
In a large independent cohort, home-cooked diets showed no health advantage over kibble, and were linked to slightly higher odds of digestive, kidney, and liver disease, likely because owners switch already-sick dogs to home-cooked food.
Under the AAFCO standard, "human grade" requires every ingredient and the finished product to be handled in compliance with human-food law (21 CFR Part 117). It defines sourcing and food-safety handling only and is not a nutrition, health, or welfare claim.
How we grade evidence
Not all studies carry the same weight. We grade each by design, strongest to weakest:
- Randomized trial. Dogs are assigned to diets and compared. The strongest design for showing cause.
- Cohort or cross-sectional study. Dogs are observed, not assigned, so it can show a link but not a cause.
- Case series or survey. A set of real cases or reports, with no comparison group.
- Case report or opinion. A single account or an expert's view.
We also tag who funded each study. Funding does not make a finding wrong, but it tells you whose interpretation to scrutinize, and we tag it on both sides.