For decades, dietary advice has leaned hard toward low-fat and fat-free dairy, based on the general principle that saturated fat raises cholesterol and heart disease risk. A study out of the University of Toronto, published earlier this year in The Journal of Nutrition, is adding to a growing body of research complicating that advice — full-fat dairy, eaten daily, didn’t raise cholesterol or cause weight gain in a 12-week trial, and came with a few real benefits.
Key Takeaways
- In a 12-week randomized trial of 74 adults with overweight or obesity, three daily servings of full-fat dairy didn’t cause meaningful weight gain, worsen body composition, or raise cholesterol compared to a low-dairy diet.
- Participants who ate more dairy saw improved blood pressure and higher intake of calcium, protein, and vitamin D.
- This research was funded by Canada’s dairy industry through a government agricultural research program — a detail not mentioned in the coverage of this study, though the trial’s randomized design is more rigorous than most observational nutrition research.
- The trial was small and short-term, and included only adults with overweight or obesity, so it doesn’t necessarily generalize to the broader population.
What the Study Actually Tested
Led by Dr. Harvey Anderson, a professor of nutritional sciences at U of T’s Temerty Faculty of Medicine, the trial randomly assigned 74 adults with overweight or obesity to one of three 12-week diets: a calorie-restricted, low-dairy plan; an energy-neutral diet with three daily servings of full-fat dairy; or an unrestricted diet also including three daily servings of full-fat dairy. All participants were counseled to follow Canada’s food guide and were given the dairy products used in the study.
After 12 weeks, the researchers found no meaningful differences in weight gain, body composition, or blood cholesterol levels between the low-dairy group and the two full-fat dairy groups. The dairy-eating participants did see improvements in blood pressure, along with higher intake of calcium, protein, and vitamin D. “Those that had three servings of dairy didn’t have adverse levels of blood cholesterol or lipids or evidence of insulin resistance,” Anderson said.
A Detail the Original Coverage Left Out
This is worth stating plainly: the study was funded by Dairy Research Cluster 3, a program under Canada’s Agricultural Partnership AgriScience initiative that channels dairy-industry funding into research. That funding source doesn’t appear in the article that prompted this piece, or in the original University of Toronto press release. It’s a relevant fact for readers to have, not because it proves the findings are wrong, but because nutrition research funded by an industry with a direct stake in the outcome deserves that context. Food-policy researchers who track this pattern across nutrition science broadly have found industry-funded studies are considerably more likely to reach conclusions favorable to the sponsor than independently funded research — a structural pattern in the field, not evidence about this specific trial. In this study’s favor, a randomized controlled trial is a more rigorous design than the observational research that makes up much of nutrition science, and it was peer-reviewed and published in an established journal — but the funding is still worth knowing when weighing how much confidence to place in the result.
Why the Findings Might Make Biological Sense Anyway
Anderson and other researchers point to something called the dairy matrix hypothesis to help explain why whole dairy foods might behave differently than the sum of their individual nutrients would predict. “With dairy products, it’s got two proteins — casein and whey — that are bound together with fat and with nutrients mixed in,” Anderson said. The idea is that this physical structure affects how slowly and steadily nutrients are absorbed, potentially changing dairy’s overall metabolic impact compared to isolated saturated fat consumed on its own. It’s a real, actively studied hypothesis in nutrition science, though it’s also not yet the kind of settled mechanism that fully resolves the broader saturated-fat debate.
What This Doesn’t Establish
Beyond the funding question, there are real limits to what a trial like this can show. Seventy-four participants over 12 weeks is a relatively small, short study — it can’t speak to what happens over years of full-fat dairy consumption, and it only enrolled adults who were already overweight or obese, so the results may not extend cleanly to people with different starting body compositions or health profiles. It’s also one trial among a broader, genuinely mixed body of research on dairy fat, some of it funded independently and some of it, like this study, industry-supported.
The Practical Takeaway
Anderson’s own advice, notably, isn’t a specific call to load up on dairy: “Keep it simple, eat a variety of foods and not too much of anything.” For people already eating dairy and wondering whether the full-fat version is worth avoiding, this trial adds real (if industry-funded and short-term) evidence that moderate full-fat dairy intake isn’t the metabolic liability it’s traditionally been assumed to be — while stopping well short of proving it’s a health upgrade everyone should make.
Source: Anderson, G.H., Zhou, C.Z.C., Vien, S., et al. (2026). The Effect of Three Daily Servings of Full-Fat Dairy for 12 Weeks on Body Weight, Body Composition, Energy Metabolism, Blood Lipids, and Dietary Intake of Adults with Overweight and Obesity. The Journal of Nutrition, 156(4), 101373. DOI: 10.1016/j.tjnut.2026.101373.