Three daily servings of full-fat dairy do not worsen weight or blood markers

By Priyanjana Pramanik, MSc.Reviewed by Susha Cheriyedath, M.Sc.Jan 26 2026

A randomized Canadian trial shows that three daily servings of full-fat dairy can fit safely into a healthy eating pattern without harming weight or cardiometabolic markers while improving key nutrient intake.

Study: 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. Image Credit: Skylines / Shutterstock

In a recent study published in The Journal of Nutrition, researchers investigated whether adding three daily servings of full-fat dairy to the diets of adults with overweight and obesity would affect nutrient intake, cardiometabolic health, and body weight. The primary aim was to assess safety and dietary compatibility rather than efficacy.

Compared with diets low in dairy, daily consumption of full-fat dairy for 12 weeks did not negatively affect blood glucose, blood lipids, body composition, or weight. It improved calcium and protein intake without conferring measurable cardiometabolic benefit or harm.

Public Health Context and Dietary Guidance

Obesity and cardiometabolic diseases are major public health challenges in Canada, contributing substantially to healthcare costs and chronic disease burden. Nutrition is therefore a key target for prevention strategies.

Dairy foods are nutrient-dense and provide high-quality protein, calcium, and other essential micronutrients. Evidence from observational and intervention studies suggests that both low-fat and full-fat dairy consumption may be associated with healthier body weight and neutral or favorable cardiometabolic markers.

Despite this, full-fat dairy consumption has declined in Canada, largely due to concerns about saturated fat and recommendations favoring plant-based diets. In 2019, Canada’s Food Guide (CFG) shifted away from explicit dairy recommendations and emphasized plant-based foods. However, it did not clearly address emerging evidence on full-fat dairy within mixed dietary patterns.

Study Objectives and Rationale

Given limited experimental evidence on full-fat dairy intake in metabolically healthy adults with overweight or obesity, researchers aimed to assess whether regular consumption of full-fat dairy could be safely incorporated into a healthy dietary pattern guided by the CFG, rather than to test full-fat dairy as a therapeutic intervention.

Study Design and Participants

The parallel-group study was conducted at two Canadian universities and included 74 healthy adults aged 25 to 60 years with overweight or obesity. Participants were randomly assigned to one of three dietary intervention groups.

The first group followed a low-dairy, energy-restricted diet with a targeted daily deficit of 500 kilocalories. The second group consumed an energy-neutral diet, including three daily servings of full-fat dairy, intended to replace the 500-kilocalorie restriction. The third group followed an ad libitum diet, including three daily servings of full-fat dairy, with no caloric restriction. All participants received regular dietary counselling aligned with the CFG.

Measurements and Dietary Monitoring

Anthropometric measurements, body composition, resting metabolic rate, blood pressure, fasting blood markers, urine samples, and dietary intake were assessed at baseline and throughout the intervention. Dietary intake was monitored using food records, food trackers, and dairy logs.

Body Weight, Composition, and Metabolic Outcomes

Participants had clinically normal cardiometabolic profiles at baseline with no significant differences between groups. Over 12 weeks, body weight and body mass index (BMI) decreased modestly in the energy-restricted low-dairy group while remaining stable in both full-fat dairy groups. No significant changes were observed in waist circumference, body fat, fat-free mass, or resting metabolic rate across treatments.

Systolic blood pressure decreased in the ad libitum dairy group and the energy-restricted group, while hip circumference declined slightly only in the ad libitum dairy group. Blood lipids, glucose, and glycated hemoglobin were unaffected by dairy intake. Triglycerides rose temporarily during week four before returning to baseline by week twelve, with no sustained between-group differences.

Dietary Intake and Pattern Changes

Dietary intake analyses showed increased protein and calcium intake in the full-fat dairy groups, with calcium intake exceeding recommended levels, unlike the low-dairy group. Participants across all groups improved adherence to CFG recommendations, including higher whole-grain intake and reduced consumption of processed foods, animal proteins, and alcohol. These changes reflected the impact of structured dietary counselling rather than dairy intake alone.

Across the 12-week intervention, overall dietary patterns improved similarly across treatment groups. Fruit and vegetable intake remained stable, with higher consumption among males. Whole-grain intake increased over time, while white and whole-wheat products decreased regardless of treatment.

Animal protein and ruminant meat consumption declined, whereas plant protein intake showed minimal change. Beverage consumption showed modest reductions, particularly for unsweetened beverages and alcohol. Food skills usage remained stable, though females reported greater use of food labels than males.

Nutrition Knowledge and Adherence

Nutrition knowledge and dietary compliance improved over the 12-week intervention. Participants reported greater understanding and application of the 2019 CFG, with high adherence to dietary counselling and dairy intake targets. Most participants expressed willingness to continue the recommended eating patterns beyond the study period.

Interpretation and Clinical Relevance

These findings demonstrate that consuming three daily servings of full-fat dairy for approximately three months does not negatively affect body weight, cardiometabolic markers, or metabolic health in metabolically healthy adults with overweight or obesity when combined with dietary guidance from the CFG.

The results support the view that full-fat dairy can be incorporated into a healthy dietary pattern while improving intake of limiting nutrients such as calcium and protein, without evidence of short-term cardiometabolic harm. The findings should be interpreted as evidence of dietary compatibility rather than cardiometabolic benefit. Strengths include the randomized design, comprehensive dietary counselling, and detailed assessment of metabolic outcomes.

Study Limitations and Future Directions

A smaller-than-planned sample size limited the study due to disruptions caused by the coronavirus disease 2019 (COVID-19) pandemic and its relatively short duration. Participants were metabolically healthy at baseline, and the study was not powered to detect long-term cardiometabolic outcomes, which may limit generalizability.

Incorporating full-fat dairy into the diet of adults with overweight or obesity does not appear to pose adverse short-term effects on body weight or cardiometabolic health and may help address nutrient gaps. Continued research in broader populations and over longer durations is warranted, particularly in individuals with existing metabolic disease.