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