NCT00710398

Brief Summary

Diets all share the same principle: eat less energy than you need. This results in weight loss. However, the weight loss is usually a combination of a loss of body fat and muscle mass. Additionally, one's bones may begin to weaken, albeit very slowly, while on a diet, which could have serious long-term consequences. Thus, the investigators believe that the goal of any weight loss strategy should be to lose body fat and spare muscle. The investigators reasoning is two-fold. 1) Fat is not only stored under the skin, but also in and around the internal organs. When this occurs, the organ itself may not function properly. Losing fat mass is a very good thing from a health standpoint, since fat is not just a storage site for extra energy. Scientists have now shown that 'extra' body fat itself can actually secrete substances and when these substances get into your blood, they cause many problems and may even contribute to the development of diabetes. 2) Sparing muscle as an individual loses weight is very important. Muscle is a very 'metabolically active' tissue and is, by analogy, like the body's furnace. Muscle burns fuel from the food individuals eat and also from stored fuels, like fat. Hence, it's easy to see why you don't want to lose muscle because you'd be losing one of your body's best fat burners. More importantly, muscle is also a big storage site and furnace for blood sugar. In people with diabetes (elevated blood sugar), a big part of the problem is with their muscles - they simply do not take up and store or burn enough sugar. For these reasons, your goal should be to lose fat and preserve muscle while dieting. There are many different diets to choose from (e.g. high protein, low carbohydrate, high fat, high fiber, etc.). A diet that has been shown to be quite successful, however, is one that is higher in protein (but not excessive). Thus, in this study, the investigators are proposing to test whether a higher protein (with dairy) and calcium diet promotes body fat loss and muscle mass retention. The investigators believe that a diet higher in protein (with an emphasis on dairy), but still within accepted healthy ranges, with higher dietary calcium may result in greater loss of body fat and retention of muscle than a diet with a conventional amount of protein and adequate calcium or a conventional amount of protein with little calcium (i.e. low dairy). Based on previous research, the investigators think that people with low calcium intakes to begin with would stand to benefit the most. There is also a good reason to think that the high protein/high calcium diet may result in greater reductions in blood cholesterol and blood sugar, both of which would reduce a person's risk for heart disease and diabetes. The investigators will test this diet in premenopausal women who are overweight or obese. The investigators believe that this group is a good one to target for several reasons. First, women of this age who are overweight or obese are, if they continue to carry this excess weight, are at serious risk for developing chronic diseases such as heart disease, diabetes, and possibly cancer at an early age. Second, these women will often begin to gradually consume less dairy because many perceive dairy foods as fattening. Thus, if the investigators proposals are correct the investigators will hopefully be able to equip health professionals with a tried and tested, palatable, dietary strategy in a population segment who, because of their age, would benefit greatly were their disease risk to be reduced.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
90

participants targeted

Target at P50-P75 for not_applicable

Timeline
Completed

Started Jul 2008

Typical duration for not_applicable

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

July 1, 2008

Completed
Same day until next milestone

Study Start

First participant enrolled

July 1, 2008

Completed
3 days until next milestone

First Posted

Study publicly available on registry

July 4, 2008

Completed
1.8 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 1, 2010

Completed
8 months until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2011

Completed
Last Updated

July 20, 2011

Status Verified

July 1, 2011

Enrollment Period

1.8 years

First QC Date

July 1, 2008

Last Update Submit

July 19, 2011

Conditions

Keywords

Dairy ProductsDietary ProteinBody CompositionFat mass lossLean mass gainPre-menopausal Women

Outcome Measures

Primary Outcomes (1)

  • Fat mass, lean mass, bone mass (BMD, BMC), total mass (measured via DXA scan)

    Measured at weeks 0, 8 and 16

Secondary Outcomes (10)

  • Blood sample analyses (lipids)

    Measured at weeks 0, 4, 8, 12 and 16

  • Muscle and adipose tissue biopsies

    Measured at weeks 0 and 16

  • Food record macronutrient and micronutrient analyses (7-day at beginning and end, and 3-day throughout intervention)

    Biweekly from weeks 0-16

  • Resting Energy Expenditure (metabolic cart determination).

    Measured at weeks 0 and 16

  • Fitness and strength measures (modified Astrand Test and 1 RM test)

    Measured at weeks 0 and 16

  • +5 more secondary outcomes

Study Arms (3)

Control

EXPERIMENTAL

A group consuming twice daily (post-exercise and in morning/afternoon) drinks containing no dairy protein or calcium. Daily protein intake (15% total kcals) should be from non-dairy sources (i.e. meat, egg, fish, chicken, wheat gluten).

Behavioral: Exercise - Aerobic and ResistanceBehavioral: Dietary - Caloric Restriction

Dairy Protein

EXPERIMENTAL

A group consuming twice daily drinks (post-exercise and morning) containing 1% chocolate milk (in 1.5 cup servings = 3 cups/d). Daily protein intake is set at 15% total kcals with \~8% coming from dairy sources.

Behavioral: Exercise - Aerobic and ResistanceBehavioral: Dietary - Caloric Restriction

High Dairy Protein

EXPERIMENTAL

A group consuming twice daily drinks of 1% artificially sweetened chocolate milk (in 1.5 cup servings = 3 cups/d). Their diet contains 30% protein (as opposed to only 15% in the Con and DairyPro groups) with at least 50% of that coming from dairy sources.

Behavioral: Exercise - Aerobic and ResistanceBehavioral: Dietary - Caloric Restriction

Interventions

Subjects will perform exercise (aerobic and resistance) 7d/wk and will exercise supervised 5d/wk. Exercise will be carried out to expend 250 kcals/day. Supervised resistance training sessions will take place 2 days/wk and aerobic exercise will take place every day. During the resistance exercise sessions, subjects will engage in a circuit weightlifting routine using guided motion machines. During the aerobic sessions, subjects may choose whatever exercise modality they like (e.g. walking on track or treadmill, biking, elliptical, etc.). Subjects will wear devices that measure energy expenditure to get a better idea of the intensity and duration needed to expend 250 kcals with their exercise machine/modality of choice.

ControlDairy ProteinHigh Dairy Protein

Subjects will be counselled on their respective hypocaloric diets during the 16 wk period. Adherence to the prescribed diet will be assessed via collection of assigned food records (biweekly), frequent contact with subjects, and regular dietary counseling sessions. The daily dietary energy deficit will be 500 kcal per day based on the subjects' estimated daily caloric requirements (based on height, weight, age, sex), multiplied by a sedentary activity factor. Additionally, subjects will consume 2 drinks per day that will differ depending on their randomization allocation. Subjects in the Dairy Protein and High Dairy Protein group will be provided with dairy products (e.g. milk, cheese, yogurt) to consume on a weekly basis to help facilitate their prescribed dairy and dietary protein intake.

ControlDairy ProteinHigh Dairy Protein

Eligibility Criteria

Age19 Years - 45 Years
Sexfemale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Healthy pre-menopausal females
  • Body Mass Index (BMI) between 27-40 kg/m2
  • Low dairy consumption (\~\<500 mg/d Ca2+)
  • Sedentary lifestyle (i.e., exercise less than once/week)
  • Regular menstrual cycle

You may not qualify if:

  • Allergy to dairy protein
  • Lactose intolerance
  • Vegan diet
  • Pregnant
  • Taking vitamin or mineral supplements
  • Have a gastrointestinal disease or condition
  • Recent orthopedic injury
  • Diagnosed with heart, kidney, liver or pancreatic disease
  • Smoker
  • Alcohol consumption of more than 2 drinks/day

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

McMaster University

Hamilton, Ontario, L8S4K1, Canada

Location

Related Publications (2)

  • Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Diets higher in dairy foods and dietary protein support bone health during diet- and exercise-induced weight loss in overweight and obese premenopausal women. J Clin Endocrinol Metab. 2012 Jan;97(1):251-60. doi: 10.1210/jc.2011-2165. Epub 2011 Nov 2.

  • Josse AR, Atkinson SA, Tarnopolsky MA, Phillips SM. Increased consumption of dairy foods and protein during diet- and exercise-induced weight loss promotes fat mass loss and lean mass gain in overweight and obese premenopausal women. J Nutr. 2011 Sep;141(9):1626-34. doi: 10.3945/jn.111.141028. Epub 2011 Jul 20.

MeSH Terms

Conditions

OverweightObesity

Interventions

Exercise

Condition Hierarchy (Ancestors)

OvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and Symptoms

Intervention Hierarchy (Ancestors)

Motor ActivityMovementMusculoskeletal Physiological PhenomenaMusculoskeletal and Neural Physiological Phenomena

Study Officials

  • Stuart M Phillips, Ph.D.

    Department of Kinesiology, McMaster University

    PRINCIPAL INVESTIGATOR
  • Andrea R Josse, M.Sc.

    Department of Kinesiology, McMaster University

    STUDY DIRECTOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER

Study Record Dates

First Submitted

July 1, 2008

First Posted

July 4, 2008

Study Start

July 1, 2008

Primary Completion

May 1, 2010

Study Completion

January 1, 2011

Last Updated

July 20, 2011

Record last verified: 2011-07

Locations