For decades, people have been advised to choose low-fat or fat-free dairy products to protect heart health and control body weight. However, growing scientific evidence suggests that full-fat dairy may not pose the health risks traditionally associated with it.
A new Canadian study led by University of Toronto professor Harvey Anderson has added to this evidence, finding that consuming three servings of full-fat dairy daily for 12 weeks did not cause harmful changes in body weight, body composition, energy metabolism or blood cholesterol levels.
The findings also showed that participants who consumed more dairy experienced improvements in blood pressure and obtained higher amounts of several essential nutrients.
Published in The Journal of Nutrition, the study raises questions about long-standing dietary recommendations and suggests that the health effects of dairy may involve more than its saturated fat content alone.
Why full-fat dairy has been discouraged
For decades, nutrition guidelines in Canada and several other countries have recommended low-fat or fat-free milk, yoghurt and other dairy products. The primary concern has been saturated fat, which can increase levels of low-density lipoprotein (LDL), commonly known as “bad” cholesterol.
High LDL levels can contribute to fatty deposits in arteries, increasing the risk of heart attacks, strokes and other cardiovascular diseases over time.
As full-fat dairy contains more saturated fat than reduced-fat alternatives, health authorities have traditionally advised limiting its consumption.
However, studies examining the actual health effects of full-fat dairy have produced mixed findings.
Anderson, a professor of nutritional sciences at the University of Toronto’s Temerty Faculty of Medicine, noted that numerous human studies have found no clear link between full-fat dairy consumption and adverse health outcomes.
Some research has even suggested potential protective effects. A recent study led by Temerty Medicine professor Kozeta Milliku, for example, found an association between whole-fat milk consumption and a lower risk of childhood obesity.
Such findings have encouraged researchers to investigate whether dairy products affect the body differently from what might be expected based on their individual nutrients.
What happened when adults consumed full-fat dairy daily?
To examine the issue, Anderson and his colleagues conducted a 12-week study involving 74 adults with overweight or obesity.
Participants were randomly divided into three groups, each following a different dietary approach.
The first group followed a calorie-restricted diet containing little dairy. The second consumed three servings of dairy daily while maintaining an energy-neutral diet, meaning their calorie intake was intended to match the energy they expended. The third group also consumed three daily servings of dairy but had no specific restrictions on their overall calorie intake.
All participants received dietary guidance based on Canada’s food guide, while the researchers provided full-fat dairy products throughout the study.
After 12 weeks, the researchers assessed several indicators of metabolic health, including body weight, body composition and cholesterol levels.
