A Canadian study led by University of Toronto professor Harvey Anderson found that three servings of full-fat dairy a day did not worsen body weight, body composition, energy metabolism or blood lipid levels over 12 weeks.
The findings, published in The Journal of Nutrition, land at a moment when many readers are still being told to choose low-fat dairy products. For decades, dietary advice in Canada and many other countries has steered people away from full-fat dairy because dairy foods contain saturated fat and have been tied to cholesterol and cardiovascular risk.
In the study, 74 adults with overweight or obesity were randomly assigned to one of three dietary groups: a low-dairy, calorie-restricted diet, an energy-neutral diet with three servings of dairy each day, or an unrestricted diet that also included three daily servings of dairy. Everyone received guidance on following Canada's food guide, and the people in the dairy groups were supplied with full-fat dairy products during the study.
After 12 weeks, researchers found no meaningful differences in weight gain, body composition or cholesterol levels between the low-dairy group and those eating three servings of dairy each day. The participants who consumed more dairy also had improvements in blood pressure and took in more calcium, protein and vitamin D, three nutrients that can matter when people are eating less energy overall.
Anderson said the people who had three servings of dairy did not show adverse levels of blood cholesterol or lipids, or evidence of insulin resistance. He added that the findings may be especially important for older adults, who often need nutrient-dense foods as energy needs fall with age.
The study does not settle every question about full-fat dairy, and it leaves one practical detail open: which specific dairy foods were included in the supplied products. What it does show is sharper than the old cautionary advice suggests. For these adults, full-fat dairy was not the problem many guidelines assumed it would be.
