Role of Dairy Products in Weight Maintenance

This study has been completed.
Sponsor:
Collaborators:
National Dairy Council
University of Kansas
Information provided by:
University of Tennessee
ClinicalTrials.gov Identifier:
NCT00686426
First received: May 27, 2008
Last updated: May 28, 2008
Last verified: May 2008
  Purpose

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.


Condition Intervention
Obesity
Weight Gain
Dietary Supplement: Dairy Foods

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Prevention
Official Title: Role of Dairy Products in Weight Maintenance: Prevention of Weight Regain Following Weight Loss

Resource links provided by NLM:


Further study details as provided by University of Tennessee:

Primary Outcome Measures:
  • Body weight change [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Body Fat Change [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Enrollment: 338
Study Start Date: November 2003
Study Completion Date: July 2007
Primary Completion Date: February 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: 1
Low Dairy
Dietary Supplement: Dairy Foods
< 1 standard dairy serving/day
Experimental: 2
Adequate Dairy
Dietary Supplement: Dairy Foods
Adequate dairy (> 3 standard daily servings)

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.

  Eligibility

Ages Eligible for Study:   25 Years to 50 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00686426

Locations
United States, Kansas
University of Kansas
Lawrence, Kansas, United States, 66045
United States, Tennessee
The University of Tennessee
Knoxville, Tennessee, United States, 37996-1920
Sponsors and Collaborators
University of Tennessee
National Dairy Council
University of Kansas
Investigators
Principal Investigator: Michael B Zemel, PhD University of Tennessee
Principal Investigator: Joseph E Donnelly, PhD University of Kansas
  More Information

No publications provided by University of Tennessee

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Michael B. Zemel, the University of Tennessee
ClinicalTrials.gov Identifier: NCT00686426     History of Changes
Other Study ID Numbers: DMI-993
Study First Received: May 27, 2008
Last Updated: May 28, 2008
Health Authority: United States: Institutional Review Board

Keywords provided by University of Tennessee:
Obesity
Weight gain
regain
dairy
calcium

Additional relevant MeSH terms:
Obesity
Weight Gain
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Body Weight Changes

ClinicalTrials.gov processed this record on September 14, 2014