Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Prof Simone French


Contact details

Division of Epidemiology
& Community Health
1300 S 2nd St
United States of America
+1 612 626 8495

Additional identifiers

EudraCT number number

Protocol/serial number

R01 HD 037743

Study information

Scientific title


Cal Girls

Study hypothesis

It was hypothesised that the behavioural intervention would result in increases in dietary Calcium (Ca) intake and weight-bearing physical activity (PA), and in the rate of bone mass accrual. Innovative aspects of the present study included:
1. Its focus on changing eating and PA behaviors to increase bone mass growth
2. Its focus on pre-adolescent girls, a group at risk for declines in Ca intake and PA levels as they develop into adolescence
3. Its unique collaboration with a community-based organisation (the Girl Scouts of America) as a channel to implement a health behaviour intervention

Ethics approval

The study was reviewed and approved by the University of Minnesota Research Participants Internal Review Board.

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type

Quality of life

Patient information sheet


Osteoporosis prevention


Thirty 5th-grade Girl Scout troops were recruited and randomised to a two-year behavioural intervention program (n = 15 troops) or to a no-treatment control group (n = 15 troops). The behavioural program was implemented during 5th and 6th grades by trained troop leaders as part of the regular troop meetings. The intervention program was based on Social Cognitive Theory and consisted of ten 90-minute activity-based sessions during each of the two years. It focused on the development of behavioural skills to choose Ca-rich foods and to engage in weight-bearing physical activity. Behavioural goals for the intervention were to
increase daily dietary Ca intake to 1300 mg/day (increase of 4 daily servings of Ca rich foods; about 800 Ca mg/day) and to increase weight-bearing physical activity to 120 minutes per week. A continuously available, interactive web-based program, and a one-week summer camp between 5th and 6th grade years, were implemented as components of the intervention program. Parents were also targeted through the web-based program.

Control troops did not receive any program and conducted their usual troop meeting activities during the two-year intervention period.

Evaluation was conducted with individual girls and a parent at clinic visits at baseline prior to randomisation, at one-year follow-up, and at the end of the study (two year follow-up).

Intervention type



Not Specified

Drug names

Primary outcome measure

Change in areal bone mineral content (aBMC) was the primary outcome variable for the study because it best reflects bone mass change in developing children.

Secondary outcome measures

Not provided at time of registration

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

30 5th-grade Girl Scout troops from the Minneapolis and St Paul metropolitan area were recruited to take part in the study through mailed fliers to troop leaders and troop leader meeting announcements. Troop eligibility criteria were:
1. Troop size greater than or equal to 8 girls
2. Parental consent and girl assent from each troop member to participate in troop meetings with intervention program activities
3. Troop plans to remain together at minimum two more years

Participant type


Age group




Target number of participants


Participant exclusion criteria

Not provided at time of registration

Recruitment start date


Recruitment end date



Countries of recruitment

United States of America

Trial participating centre

Division of Epidemiology
United States of America

Sponsor information


University of Minnesota (USA)

Sponsor details

Division of Epidemiology
& Community Health
1300 S 2nd St
United States of America
+1 612 624 1818

Sponsor type




Funder type


Funder name

National Insititutes of Health (NIH) (USA) (ref: R01 HD 037743)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Results in

Publication citations

  1. Results

    French SA, Story M, Fulkerson JA, Himes JH, Hannan P, Neumark-Sztainer D, Ensrud K, Increasing weight-bearing physical activity and calcium-rich foods to promote bone mass gains among 9-11 year old girls: outcomes of the Cal-Girls study., Int J Behav Nutr Phys Act, 2005, 2, 8, doi: 10.1186/1479-5868-2-8.

Additional files

Editorial Notes