Role of Dairy Products in Weight Maintenance

May 28, 2008 updated by: University of Tennessee

Role of Dairy Products in Weight Maintenance: Prevention of Weight Regain Following Weight Loss

The goal of the current study is to determine the role of dairy in similarly preventing weight and fat re-gain in obese adults who have successfully completed a weight loss diet program.240 obese subjects will undergo a meal-replacement-based weight loss plan designed to produce a 10 kg weight loss in 8-12 weeks. Upon achieving the weight loss goal, subjects will be randomly assigned to either a low-dairy or high-dairy eucaloric weight maintenance diet for two years. Macronutrient distribution will be maintained constant and set at approximately the U.S. average. Primary outcomes include changes in body weight, body fat and anatomical distribution of fat (via dual x-ray absorptiometry) and resting metabolic rate and substrate oxidation (via respiratory calorimetry); Secondary outcomes include blood pressure, circulating glucose, insulin, lipids and calcitrophic hormones. on prevention of weight regain in humans has not yet been assessed in clinical trials.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Dietary calcium plays a pivotal role in the regulation of energy metabolism, as we have found high calcium diets to attenuate adipocyte lipid accretion and weight gain during periods of over-consumption of an energy-dense diet and to increase lipolysis and preserve thermogenesis during caloric restriction, thereby markedly accelerating weight loss. Our studies of the agouti gene demonstrate a key role for intracellular Ca2+ in regulating adipocyte lipid metabolism and triglyceride storage, with increased intracellular Ca2+ resulting in stimulation of lipogenic gene expression and lipogenesis and suppression of lipolysis, resulting in adipocyte lipid filling and increased adiposity. Moreover, the increased calcitriol produced in response to low calcium diets stimulates adipocyte Ca2+ influx and, consequently, promotes adiposity, while higher calcium diets inhibit lipogenesis, promote lipolysis, lipid oxidation and thermogenesis and inhibit diet-induced obesity in mice. Notably, dairy sources of calcium exert markedly greater effects in attenuating weight and fat gain and accelerating fat loss. This augmented effect of dairy products versus supplemental calcium is likely due to additional bioactive compounds in dairy which act synergistically with calcium to attenuate adiposity. These concepts are confirmed by both epidemiological and clinical data which demonstrates that increasing dietary calcium results in significant reductions in adipose tissue mass in obese humans in the absence of caloric restriction and markedly accelerates the weight and body fat loss secondary to caloric restriction, while dairy products exert markedly greater (nearly two-fold compared to calcium supplements) effects. These data indicate an important role for dairy products in both the prevention and treatment of obesity. However, weight maintenance following successful weight loss (i.e. prevention of regain) is at least as important as strategies to initially achieve weight loss, as most individuals who successfully lose weight are not successful in maintaining this weight loss. We have recently demonstrated that ad libitum re-feeding of dairy-rich following weight loss in mice on an energy restricted mice prevented the suppression of adipose tissue lipolysis and fat oxidation that otherwise accompanies such re-feeding and markedly upregulated skeletal muscle fat oxidation. Consequently, although animals re-fed low calcium diets rapidly regained all of the weight and fat that had been lost, animals fed high calcium diets exhibited a shift in energy partitioning and a 50-85% reduction in weight and fat gain; moreover, dairy exerted markedly greater effects than supplemental calcium on weight and fat regain. However, the effect of dairy on prevention of weight regain in humans has not yet been assessed in clinical trials. Accordingly, the goal of the current study is to determine the role of dairy in similarly preventing weight and fat re-gain in obese adults who have successfully completed a weight loss diet program.

340 obese subjects will undergo a meal-replacement-based weight loss plan designed to produce a 10 kg weight loss in 8-12 weeks. Upon achieving the weight loss goal, subjects will be randomly assigned to either a low-dairy or high-dairy eucaloric weight maintenance diet for two years. Macronutrient distribution will be maintained constant and set at approximately the U.S. average. Primary outcomes include changes in body weight, body fat and anatomical distribution of fat (via dual x-ray absorptiometry) and resting metabolic rate and substrate oxidation (via respiratory calorimetry); Secondary outcomes include blood pressure, circulating glucose, insulin, lipids and calcitrophic hormones.

Study Type

Interventional

Enrollment (Actual)

338

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Kansas
      • Lawrence, Kansas, United States, 66045
        • University Of Kansas
    • Tennessee
      • Knoxville, Tennessee, United States, 37996-1920
        • The University of Tennessee

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

25 years to 50 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Body mass index (BMI) 30-39.9 kg/m2
  • Age 25-50 years
  • No more than 3 kg weight loss during past three months
  • Negative pregnancy test at entry; women of childbearing potential may be enrolled if they have had a tubal ligation or use one of the following means of contraception: condom, diaphragm, oral or implanted contraceptives, or intrauterine device. Women in exclusive relationships with male partners who have had a successful vasectomy will not be required to use any additional means of birth control.

Exclusion Criteria:

  • BMI < 30 or >40
  • Type II diabetes requiring the use of any oral antidiabetic agent and/or insulin (because of confounding effects on body weight regulation)
  • Adverse response to study foods (lactose intolerance, dairy intolerance, dairy allergy); this will be determined by self-report.
  • History or presence of significant metabolic disease which could impact on the results of the study (i.e. endocrine, hepatic, renal disease)
  • History of eating disorder
  • Presence of active gastrointestinal disorders such as malabsorption syndromes
  • Pregnancy or lactation
  • Use of obesity pharmacotherapeutic agents within the last 6 months
  • Use of over-the-counter anti-obesity agents (e.g. those containing phenylpropanalamine, ephedrine and/or caffeine) within the last 6 months
  • Recent (past 12 weeks) use of tobacco
  • Recent (current or past 12 weeks) use of any psychotropic medication
  • Recent (past four weeks) initiation of an exercise program
  • Recent (past twelve weeks) initiation of hormone replacement therapy or change in HRT regimen
  • Recent (past twelve weeks) initiation of hormonal birth control or change in hormonal birth control regimen

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: 1
Low Dairy
Dietary supplement: Dairy Foods
Adequate dairy (> 3 standard daily servings)
Dietary supplement: Dairy Foods
< 1 standard dairy serving/day
Experimental: 2
Adequate Dairy
Dietary supplement: Dairy Foods
Adequate dairy (> 3 standard daily servings)
Dietary supplement: Dairy Foods
< 1 standard dairy serving/day

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Body weight change
Time Frame: 6 months
6 months
Body Fat Change
Time Frame: 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Tennessee

Collaborators

University of Kansas
National Dairy Council

Investigators

  • Principal Investigator: Michael B Zemel, PhD, University of Tennessee
  • Principal Investigator: Joseph E Donnelly, PhD, University Of Kansas

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

November 1, 2003

Primary Completion (Actual)

February 1, 2007

Study Completion (Actual)

July 1, 2007

Study Registration Dates

First Submitted

May 27, 2008

First Submitted That Met QC Criteria

May 28, 2008

First Posted (Estimate)

May 29, 2008

Study Record Updates

Last Update Posted (Estimate)

May 29, 2008

Last Update Submitted That Met QC Criteria

May 28, 2008

Last Verified

May 1, 2008

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • DMI-993

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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