Harvey Anderson, a professor of nutritional sciences at University of Toronto's Temerty Faculty of Medicine, led a study showing that adults consuming three servings of full-fat dairy daily for 12 weeks did not experience harmful changes in body weight, body composition, energy metabolism, or blood cholesterol levels compared with participants eating little dairy.
The research, published in The Journal of Nutrition, involved 74 adults with overweight or obesity assigned to three dietary groups. One followed a calorie-restricted diet with little dairy. The other two consumed three daily servings of dairy, with one group maintaining calorie balance and the other eating without specific calorie restrictions. All participants received guidance based on Canada's food guide, and researchers supplied the dairy products.
Participants consuming more dairy showed improvements in blood pressure and obtained greater amounts of calcium, protein, and vitamin D. Those with three servings daily did not show meaningful differences in weight gain, body composition, or blood cholesterol compared with the low-dairy group.
"Those that had three servings of dairy didn't have adverse levels of blood cholesterol or lipids or evidence of insulin resistance," Anderson says.
Anderson suggests the dairy matrix hypothesis may explain these findings. This theory proposes that the physical structure of food influences how the body processes nutrients. In dairy products, two proteins—casein and whey—bind with fat and mixed nutrients. This complex arrangement may regulate how quickly nutrients release during digestion, potentially producing different metabolic effects than consuming saturated fat alone would produce.
Anderson notes the study was relatively small and lasted only three months. Longer and larger studies are needed to determine whether findings translate into lasting health benefits or changes in cardiovascular disease risk.
The researchers believe results could be particularly relevant for older adults who need sufficient protein and essential nutrients while consuming fewer calories, since dairy products offer concentrated nutrition in familiar, convenient foods.