Researchers at the University of Helsinki took 46 dogs, fed half of them kibble and half of them raw meat, and drew blood before and after. The trial lasted a median of 4.5 months. The results, published in a peer-reviewed study in The Veterinary Journal, put hard numbers on the raw vs kibble question.

The kibble-fed dogs came out worse on nearly every marker measured.

This was a real diet intervention, not a survey.

The DogRisk research group recruited 46 client-owned Staffordshire Bull Terriers and split them into two groups. One group ate a typical commercial kibble loaded with non-fiber carbohydrates from rice and maize. The other group ate a raw meat-based diet with zero non-fiber carbs and plenty of fat and protein.

Then the researchers tracked blood sugar, insulin, glucagon, cholesterol, triglycerides, ketones, and bodyweight in every dog.

The kibble group's blood work moved in one direction: the wrong one.

Long-term blood sugar (HbA1c) went up. Total cholesterol went up. Bodyweight went up too, matching the pattern already documented in kibble and obesity research.

In humans, rising HbA1c is a known early warning sign for type 2 diabetes.

The raw group moved the opposite way on almost every number.

Blood glucose dropped. Cholesterol dropped. Glucagon dropped, and so did the triglyceride-glucose index, a marker of insulin resistance borrowed from human medicine.

The raw-fed dogs also showed the highest ketone levels, meaning their bodies were burning fat for fuel instead of processing a constant flood of starch.

This isn't the first time DogRisk caught kibble misbehaving at the cellular level.

A 2020 study in Frontiers in Veterinary Science sequenced RNA from skin biopsies of Staffies fed either kibble or raw for the same trial period. Diet changed which genes switched on in the skin, with effects tied to immune function, antioxidants, and inflammation. The sample was small — 8 dogs were sequenced — so the authors called the results preliminary.

Two different tissues, two different lab methods, one consistent pattern.

Dogs have no biological requirement for carbohydrates, and this research shows what happens when they get them anyway.

The lead researcher noted the kibble diet produced changes "often linked to adverse metabolic health" while the raw diet produced responses "generally considered favorable." That's careful academic language for a blunt finding: the food format the industry calls "complete and balanced" nudged healthy dogs toward metabolic stress in under five months. One trial on one breed won't settle everything, and the authors call for longer-term research.

If those blood markers made you look at your dog's food bag differently, the gradual transition method is the safest place to start.

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