Calcium, Dairy, and Body Fat in Adolescents

Study Overview
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Brief Summary
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Lifestyle choices,including diet,are conducive to healthy body weights in children. Dairy products and calcium supplementation have been associated with moderation of body weight and body fat. This study was designed to test the following hypotheses with overweight and obese adolescents consuming a controlled diet: Dietary calcium supplementation as calcium carbonate or dairy calcium modulates energy balance in adolescents. Increased calcium in the diet of adolescents will increase fecal fat excretion and thereby decrease fat absorption. Calcium and dairy product supplementation will increase lipid oxidation resulting in an increase in energy expenditure.

Detailed Description
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Subjects will consume a controlled diet containing 800 mg calcium for two three week periods. During one period they will also receive a frozen ice cream like product (smoothie) twice a day based on soy protein that contains no additional calcium. During the other period they will receive a similar product twice a day based on either dairy protein that contains 650 mg calcium or based on soy protein that contains 650 mg calcium as calcium carbonate

Official Title
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Calcium, Dairy, and Body Fat in Adolescents

Conditions
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Obesity, Energy Metabolism

Intervention / Treatment
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* Dietary Supplement: C (smoothies based on soy protein containing no additional calcium)
* Dietary Supplement: B (smoothies based on soy protein containing calcium)
* Dietary Supplement: A (smoothies based on dairy protein containing calcium)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Over weight (>85th percentile BMI for age) Exclusion Criteria: > 180% of ideal body weight for height Malabsorptive disorders Bone disease Liver disease Kidney disease Anemia Smoking or illegal drugs Oral contraceptives Pregnancy Medications that influence calcium metabolism

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 15 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: C<br>During one three week session of a controlled diet subjects will receive a smoothie based on soy protein two times per day that does not contain any additional calcium | Dietary Supplement: C (smoothies based on soy protein containing no additional calcium)<br>* Two smoothies per day based on soy protein containing no additional calcium<br>|
| Active Comparator: B<br>During one three week period half of the participants will receive two smoothies per day based on soy protein that contain 650 mg Ca as calcium carbonate | Dietary Supplement: B (smoothies based on soy protein containing calcium)<br>* Two smoothies daily based on soy protein containing 650 mg calcium as calcium carbonate<br>|
| Active Comparator: A<br>During one three week session subjects will receive two smoothies per day based on dairy protein containing 650 mg calcium | Dietary Supplement: A (smoothies based on dairy protein containing calcium)<br>* Two smoothies daily based on dairy protein containing 650 mg calcium<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Energy balance will be calculated by quantitating the kilocalories represented by the following components: dietary intake, excreta, physical activity, resting energy expenditure, thermic effect of food, and thermogenesis. |  | After equilibration on a controlled diet for one week, measurements will be taken over an additional two week period. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum biochemical measures of calcium metabolism (PTH, Vitamin D, and calcium) |  | Serial meausures over a 10 hour period following a meal containing calcium from the placebo, dairy or calcium carbonate supplement | 
| Calcium retention |  | Two weeks on a controlled diet following one week of equilibration on the same diet | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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calcium carbonate, obesity, dairy, energy expenditure