Researchers found that people can consume three daily servings of full-fat dairy without adversely affecting body weight, body composition, energy metabolism, or blood lipid levels.
For years, people scanning the dairy aisle have often been steered toward skim milk and reduced-fat products, largely because full-fat dairy contains saturated fat. Yet the health effects of dairy may depend on more than the amount of fat listed on the label.
Research led by University of Toronto scientist Harvey Anderson found that adults could consume three servings of full-fat dairy each day without harmful changes in body weight, body composition, energy metabolism or blood lipid levels. The results were published in the Journal of Nutrition.
Testing full-fat dairy directly
To examine the effects under controlled conditions, Anderson and his colleagues recruited 74 adults with overweight or obesity and randomly placed them into one of three dietary groups. One group followed a low-dairy, calorie-restriction diet. A second consumed three daily servings of dairy while keeping calorie intake energy-neutral, meaning participants ate roughly the amount of energy their bodies used. A third group also consumed three daily servings but did not face calorie limits. All participants were encouraged to follow Canada’s food guide.
This design allowed the researchers to separate the effects of dairy from those of calorie restriction. After 12 weeks, participants consuming three servings of dairy showed no meaningful differences in weight gain, body composition or cholesterol compared with those eating the low-dairy diet.
The higher dairy groups also recorded lower blood pressure and consumed more calcium, protein and vitamin D, nutrients that support functions such as bone maintenance, muscle health and immune activity.
“Those who had three servings of dairy didn’t have adverse levels of blood cholesterol or lipids or evidence of insulin resistance,” says Anderson, a professor of nutritional sciences in U of T’s Temerty Faculty of Medicine.
Insulin resistance occurs when the body’s cells stop responding properly to insulin, the hormone that helps move sugar from the bloodstream into cells for energy. Over time, that reduced response can increase the risk of type 2 diabetes.
Guidelines face conflicting evidence
Nutrition guidelines in Canada and many other countries have long favored fat-free or low-fat dairy. The reasoning is that reducing saturated fat may help prevent high cholesterol and lower cardiovascular disease risk.
Human research, however, has not consistently shown that eating full-fat dairy leads to worse health outcomes, Anderson says. Some investigations have even identified possible protective effects. Those include recent work led by Kozeta Miliku, an assistant professor at Temerty Medicine.
The apparent contradiction may come from viewing saturated fat in isolation rather than considering the food that contains it. Anderson and other researchers point to the dairy matrix hypothesis, which proposes that a food’s physical structure changes how its nutrients are broken down, absorbed and used.
In practical terms, dairy is not simply a collection of separate nutrients. Its proteins, fats, minerals and other components are packaged together, and that arrangement may influence how quickly they reach the body and what effects they produce.
“With dairy products, it’s got two proteins – casein and whey – that are bound together with fat and with nutrients mixed in,” Anderson says, adding that it’s this unique and complex physical structure that is responsible for the slow and steady delivery of nutrients from dairy products, and that expands their health impacts to more than just the sum of the isolated nutrients.
Whole foods reshape nutrition advice
The findings may be particularly useful for older adults, Anderson notes. As people age, their overall energy needs often decline even though they still require adequate protein, calcium, vitamin D and other nutrients.
That creates a practical challenge. Older adults may need to obtain more nutrition from fewer calories. Dairy products offer a familiar source of concentrated energy and nutrients, Anderson says, and the study found no evidence that including them increased the risk of diabetes or other chronic diseases.
The results also support a broader shift in nutrition research. Instead of judging foods mainly by a single component, such as saturated fat, researchers and policymakers may need to consider how nutrients behave when consumed together in a whole food.
Faced with constantly changing trends in food and nutrition and sometimes conflicting messaging around diet, Anderson’s advice is straightforward: “Keep it simple, eat a variety of foods and not too much of anything.”
Reference: “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” by Gerald Harvey Anderson, Corrina Zi Chen Zhou, Shirley Vien, Marisa Soo, Shekoufeh Salamat, Maryam Akbarifakhrabadi, Larissa Chomka, Priya Kathirvel, Ferhan Siddiqi, Hrvoje Fabek and Bohdan Luhovyy, 22 January 2026, The Journal of Nutrition.
DOI: 10.1016/j.tjnut.2026.101373
This research was supported by Dairy Research Cluster 3 under the Canadian Agricultural Partnership AgriScience Program and the Mitacs Accelerate program.
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