University of Toronto study challenges low-fat dairy guidelines
A 12-week trial involving 74 adults found no adverse effects on weight or cholesterol from consuming three daily servings of full-fat dairy, contradicting decades of public health advice.
A study led by Professor Harvey Anderson at the University of Toronto has cast doubt on long-standing dietary guidelines that recommend low-fat dairy products for weight management and cardiovascular risk reduction. Published in The Journal of Nutrition, the research indicates that consuming three daily servings of full-fat dairy does not negatively affect body weight, body composition, energy metabolism, or blood lipid levels.
The trial, conducted between September 2020 and February 2023, involved 74 adults with overweight or obesity. Participants were assigned to one of three dietary groups: a low-dairy calorie-restricted diet, an energy-neutral diet with three daily servings of full-fat dairy, or an unrestricted diet with the same dairy intake. After 12 weeks, researchers found no meaningful differences in weight gain, body composition, or cholesterol levels between the low-dairy group and those consuming full-fat dairy.
Professor Anderson noted that participants consuming three servings of dairy daily showed improvements in blood pressure and better intake of essential nutrients, including calcium, protein, and vitamin D. Crucially, the study found no evidence of adverse blood cholesterol or lipid levels, nor any signs of insulin resistance among those in the dairy groups.
The findings challenge the traditional nutritional logic that saturated fat in whole milk raises low-density lipoprotein cholesterol, thereby increasing cardiovascular risk. While a 2016 Harvard analysis of over 220,000 participants found that dairy fat itself was not associated with higher cardiovascular disease risk, it did link replacing dairy fat with polyunsaturated fats to a 24 per cent lower cardiovascular risk. However, the University of Toronto research suggests that the presence of dairy fat does not automatically translate into the adverse metabolic effects predicted by older models.
Current food guides in Canada and the United States continue to recommend three servings of low- or no-fat dairy for adults. The study argues that these guidelines may be overlooking recent evidence supporting the benefits of full-fat dairy. Professor Anderson highlighted a shift in nutritional thinking from focusing on individual nutrients to viewing dairy as a complex food matrix, where components such as casein, whey, fat, and minerals interact to influence health outcomes.
