The Effects of Long-term Consumption of Full-fat Dairy Products on Satiety, Body Weight and Glycemic Control

The proposed study looks at the effect of long-term diet modification with or without full-fat dairy products or restrictive eating on body weight, body composition and cardiometabolic markers in healthy overweight/obese men and women.

Study Overview

• Status: Active, not recruiting
• Conditions: Body Weight; Overweight or Obesity
• Intervention / Treatment: Other: Restrictive Eating; Other: Dairy-based commercially available food products

Detailed Description

A total of 93 males and females will participate in the study at the University of Toronto.

At the beginning and after 12 weeks, body weight, composition will be measured through Bodpod scans. Resting metabolic rate and thermogenesis will be measured by indirect calorimetry. Also, fecal samples will be collected for gut microbiome profiling along with blood for glucose, insulin, hormones, triacylglycerol, HbA1c, short-chain fatty acid, red blood cells and FGF21. Urine samples will be collected throughout the study.

A followup session at 16 weeks will reassess previous measures.

• Study Type: Interventional
• Enrollment (Estimated): 93
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Nova Scotia
    • Halifax, Nova Scotia, Canada, B3M 2J6
      • Mount Saint Vincent University
  • Ontario
    • Toronto, Ontario, Canada, M5S 3E2
      • Department of Nutritional Sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• BMI: ≥ 27 and ≤ 34.9 kg/m2
• Fasting serum glucose: ≤ 7 mmol/L
• Low ≤1 serving of dairy consumption
• Waist circumference >88cm (women) and >102cm (men)
• Willing to maintain habitual diet, physical activity pattern, and body weight throughout the trial.
• Willing to maintain current dietary supplement use throughout the trial. On test days, participant agrees not to take any dietary supplements until dismissal from the study. Failure to comply will result in a rescheduled test visit.
• Willing to abstain from alcohol consumption for 24 h prior to all test visits.
• Willing to avoid vigorous physical activity for 24 h prior to all test visits.
• Understanding the study procedures and willing to provide informed consent to participate in the study and authorization to release relevant protected health information to the study investigator

Exclusion Criteria:

• Fasting blood glucose > 7 mmol/L
• Triglycerides ≥ 2.3 mmol/L
• Smoking tobacco products and marijuana
• Thyroid problems
• Previous history of cardiovascular disease, diabetes, liver or kidney disease, inflammatory bowel disease, celiac disease, short bowel syndrome, any malabsorptive syndrome, pancreatitis, gallbladder or biliary disease.
• Presence of gastrointestinal disorder or surgeries within the past year.
• Consuming prescription or non-prescription drug, herbal or nutritional supplements known to affect blood glucose or that could affect the outcome of the study as per investigator's judgement.
• Known to be pregnant or lactating, or planning on becoming pregnant in the next 12 months.
• Irregular menstrual cycles (i.e. frequent missed cycles), menopausal or post- menopausal
• Unwillingness or inability to comply with the experimental procedures
• Known intolerance, sensitivity or allergy to dairy products
• Consumption of protein powders/protein supplements
• Extreme dietary habits
• Uncontrolled hypertension as defined by the average blood pressure measured at screening.
• Weight gain or loss of at least 10 lbs in previous three months, and history of childhood overweight or obesity
• Excessive alcohol intake
• Restrained Eaters

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low Dairy Energy Restrictive Diet; Low-dairy (<1 serving/day) and 500kcal/deficit per day energy restrictive diet	Other: Restrictive Eating; Dietitian will assist with 500 kcal/day reduction through limiting of macronutrients 45-65% energy from carbohydrates 20-35% energy from fat 10-35% energy from protein
Experimental: 3 Servings of Full-Fat Dairy with Energy Restrictive diet; Energy-restrictive diet (500 kcal/deficit per day) with 3 servings of full-fat dairy products from full-fat milk, and assorted yogurts and cheeses	Other: Restrictive Eating; Dietitian will assist with 500 kcal/day reduction through limiting of macronutrients 45-65% energy from carbohydrates 20-35% energy from fat 10-35% energy from protein; Other: Dairy-based commercially available food products; Full-fat milk (3.25% milk, 250 mL), assortment of yogurts, and cheeses
Experimental: 3 Servings of Full-Fat Dairy but no energy restriction; Normal diet (no energy restriction) with 3 servings of full-fat dairy products from full-fat milk, and assorted yogurts and cheeses	Other: Dairy-based commercially available food products; Full-fat milk (3.25% milk, 250 mL), assortment of yogurts, and cheeses

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in body weight	Each participant will attend 8 sessions biweekly in total	Starting at the beginning of the study 0 week then biweekly for 7 sessions up to 12 weeks with a followed up at 16 weeks.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fecal Collection	Gut microbiome profiling	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in blood glucose levels	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in fasting insulin (µIU/mL) levels in the blood	Each participant will attend 3 sessions in total	Change from baseline at 12 weeks
Change in gut hormone levels measured in the blood	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in triacylglycerol level (mg/dL)	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in HbA1c (mmol/mol)	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in red blood cells fatty acids	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in resting metabolic rate	Each participant will attend 3 sessions in total measured by Indirect calorimetry	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in short-chain fatty acids in the blood	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in waist and hip circumference in cm	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.
Change in lean body mass percentage measured by BodPod	Each participant will attend 3 sessions in total	Starting at the beginning of the study 0 week then at 12 weeks with a followed up at 16 weeks.

Collaborators and Investigators

• Sponsor: University of Toronto
• Collaborators: Mount Saint Vincent University
• Investigators: Principal Investigator: G. Harvey Anderson, PhD, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): September 1, 2020
• Primary Completion (Actual): September 30, 2023
• Study Completion (Estimated): December 30, 2025

Study Registration Dates

• First Submitted: May 12, 2020
• First Submitted That Met QC Criteria: May 19, 2020
• First Posted (Actual): May 22, 2020

Study Record Updates

• Last Update Posted (Actual): March 28, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Overweight; Body Weight
• Other Study ID Numbers: DFC_LTDairy_2019

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No