For many years, health guidelines recommended fat-free and low-fat dairy, citing the saturated fat in whole milk, cheese, and yogurt as harmful due to its potential to raise cholesterol and harm the heart. However, a recent study presents a different perspective. It found that adults who consumed full-fat dairy daily for 12 weeks did not experience negative effects on weight, body fat, or cholesterol, and even saw some health benefits.
This study, led by Professor Harvey Anderson of the University of Toronto and published in The Journal of Nutrition, revealed that individuals consuming three servings of full-fat dairy each day did not show significant increases in weight, body fat, cholesterol, or insulin resistance compared to those on a low-dairy diet. Surprisingly, they also improved their blood pressure and increased their intake of calcium, protein, and vitamin D.
Funded by Dairy Research Cluster 3 under the Canadian Agricultural Partnership AgriScience Program, the study investigated why full-fat dairy did not yield the expected negative outcomes. Anderson explained to Newsweek the potential reason for these results. He highlighted the complex structure of dairy products, involving two proteins, casein and whey, bound with fat and other nutrients. This intricate structure allows for a slow, steady release of nutrients, potentially enhancing the health benefits beyond what isolated nutrients might provide.
Jessica Corwin, a registered dietitian, commented on the findings, suggesting they add essential nuance to established dietary advice. Corwin, speaking to Newsweek, remarked that many who grew up during the fat-free trend can attest to its impact on cravings, satisfaction, and weight. She emphasized that while the study does not prove that full-fat dairy is healthier than low-fat dairy, it challenges the idea that full-fat dairy contributes to weight gain or deteriorates heart health markers when part of an otherwise healthy diet.
Corwin further noted the broader lesson this study imparts about nutrition science: the health effects of whole foods are not always predictable by isolating single nutrients. Dairy provides saturated fat, but it also offers high-quality protein, calcium, potassium, and other nutrients within a complex food matrix, reinforcing why whole foods should be preferred over isolated supplements.
The researchers included 74 adults classified as “overweight” or “obese”, dividing them into three groups. One group followed a low-dairy, calorie-restricted diet, another an energy-neutral diet with three daily servings of dairy, and the third had an unrestricted diet with the same dairy intake. All participants adhered to Canada’s food guide, and those consuming dairy received full-fat products throughout the study.
Traditionally, dietary guidelines in Canada and other countries have favored low-fat dairy due to links between saturated fat and heightened cholesterol and cardiovascular risk. Nevertheless, the new findings support the “dairy matrix hypothesis”, suggesting the physical structure of a food influences nutrient digestion and absorption, thus affecting a food’s health impact based on component interactions rather than isolated nutrients.
Anderson, H. G., et al. (2026). The Effect of Three Daily Servings of Full-Fat Dairy for 12 Weeks on Body Weight, Body Composition, Energy Metabolism, Blood Lipids, and Dietary Intake of Adults with Overweight and Obesity. The Journal of Nutrition.