Three Daily Servings of Full-Fat Dairy Showed No Adverse Changes Over 12 Weeks

Researchers at the University of Toronto randomly assigned 74 adults with overweight or obesity to one of three dietary approaches: a calorie-restricted, low-dairy diet; three daily servings of dairy with energy intake intended to match expenditure; or three daily servings without specific calorie restrictions. The researchers supplied full-fat dairy products, and participants received guidance based on Canada’s food guide. The 12-week study assessed body weight, body composition and metabolic measures, including blood lipids and insulin resistance.

Compared with the low-dairy group, participants assigned to three daily servings did not have meaningful differences in weight, body composition or blood cholesterol. The higher-dairy groups showed improvements in blood pressure and higher intakes of calcium, protein and vitamin D. The report does not provide numerical effect sizes for these changes.

The findings suggest no unfavorable short-term changes in the measured outcomes under the study conditions; they do not establish that full-fat dairy prevents or increases cardiovascular disease or diabetes. The sample was small, follow-up lasted only three months, and the study did not test long-term clinical outcomes. Funding included Dairy Research Cluster 3 under the Canadian Agricultural Partnership AgriScience Program and the Mitacs Accelerate program.