Effects of Whole vs. Nonfat Milk Consumption on Body Composition in Children

Study Overview
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Brief Summary
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This study will evaluate the effects of whole vs. nonfat milk consumption on body composition, cardiometabolic disease risk factors, and dietary quality.

Detailed Description
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Background The optimal type of milk is a topic of much debate. Several recent observational studies indicate that consuming whole (full-fat), compared to reduced-fat milk, is associated with less weight gain and decreased cardiometabolic disease risk. The observed beneficial effect of consuming whole milk on body weight may be due to its greater satiety value, leading to consumption of fewer calories from other lower quality (e.g., sugary) foods. Mechanistic studies indicate that substitution of carbohydrate with certain saturated fatty acids in milk increases low-density lipoprotein cholesterol (LDL-C). However, this increase has been attributed to large, buoyant particles that are less atherogenic than small, dense particles; is accompanied by an increase in high-density lipoprotein cholesterol (HDL-C); and may not elevate overall risk compared to carbohydrate. Specific Aims and Hypotheses To examine the effects of milk consumption on body composition (Aim #1) and cardiometabolic disease risk factors (Aim #2). Primary Hypothesis. Consuming whole milk will result in less weight gain compared to consuming nonfat milk. Secondary hypothesis. Consuming whole milk will decrease cardiometabolic disease risk compared to consuming nonfat milk. To explore the effects of milk consumption on dietary quality (Aim #3). Exploratory hypothesis. Consuming whole milk will improve overall dietary quality by displacing lower quality foods compared to consuming nonfat milk, particularly among children with low baseline dietary quality. Design Randomized Controlled Trial. Participants (N=200, aged 9 to 12 years, BMI≥75th percentile) will be randomly assigned for 1 year to receive: 1) Whole milk, 3 cups/d or 2) Nonfat milk, 3 cups/d. To promote adherence to the interventions, the investigators will rely on home delivery of milk using methods consistent with previous successful studies. Study Outcomes The primary outcome is change in fat mass measured by air displacement plethysmography (BodPod) at 3 time points (baseline and 6 and 12 months). To evaluate cardiometabolic disease risk factors, the investigators will obtain a plasma MetaboProfile®(LabCorp) that includes lipoprotein particle sizes and subfraction concentrations, novel measures of insulin-resistant dyslipoproteinemia and inflammation, and a conventional lipid profile. The investigators will also measure blood pressure.

Official Title
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Effects of Whole vs. Nonfat Milk Consumption on Body Composition in Children: a 1-Year RCT

Conditions
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Obesity, Diabetes, Cardiovascular Diseases

Intervention / Treatment
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* Behavioral: Whole milk
* Behavioral: Nonfat milk


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 9 to 12 years BMI ≥75th percentile for sex and age Residence in the Greater Boston catchment area Exclusion Criteria: Aversion to nonfat or whole milk Physician diagnosis of major medical illness, eating disorder, or milk allergy (lactose intolerance not exclusionary as lactase treated milk can be provided) Abnormal laboratory tests: HgA1c, TSH, hematocrit, BUN, creatinine, ALT (>1.5 normal upper limit) Plans to move away from the Greater Boston catchment area during the study period Plans to be away from home for ≥5 weeks during the study period (e.g., extended summer vacation) Change in body weight exceeding 10% during prior year Recent adherence to a special diet Chronic use of any medication or dietary supplement that could affect study outcomes Another member of the family (first degree relative) or household participating in the study

Ages Eligible for Study
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Minimum Age: 9 Years
Maximum Age: 12 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Participants will be randomly assigned for 1 year to receive home delivery of: 1) Whole milk, 3 cups a day or 2) Nonfat milk, 3 cups a day.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Whole milk<br>3 cups a day of whole milk for 1 year | Behavioral: Whole milk<br>* Weekly home delivery of whole milk, daily text messages, monthly virtual visits<br>|
| Experimental: Nonfat milk<br>3 cups a day of nonfat milk for 1 year | Behavioral: Nonfat milk<br>* Weekly home delivery of nonfat milk, daily text messages, monthly virtual visits<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Fat mass | Primary outcome for the overall study, main outcome for Specific Aim #1, measured by air displacement plethysmography (BodPod) | Change from start of trial (time of randomization) through end of trial (12 months) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lean body mass | Measured by air displacement plethysmography (BodPod) | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Percent body fat | Measured by air displacement plethysmography (BodPod) | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Height | Linear growth | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Body mass index (BMI) | Weight in kg divided by height in meters squared | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Leptin | Satiety hormone, released by fat cells, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Ghrelin | Hunger hormone, released primarily in the stomach, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Insulin-like growth factor-1 (IGF-1) | Indicator of growth hormone action, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Insulin-like growth factor-binding protein 3 (IGF-BP3) | Measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Lipoprotein insulin resistance (LPIR) | Main outcome for Specific Aim #2; a 6-component weighted score of triglyceride-rich, high-density, and low-density lipoprotein particle (TRL-P, HDL-P, LDL-P) sizes and subfraction concentrations (sum of large and very large TRL-P, large HDL-P, small LDL-P), measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Triglyceride-rich lipoprotein particle (TRL-P) size | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| High-density lipoprotein particle (HDL-P) size | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Low-density lipoprotein particle (LDL-P) size | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Sum of large and very large TRL-P concentration | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Large HDL-P concentration | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Small LDL-P concentration | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Large LDL-P concentration | Measured by nuclear magnetic resonance spectroscopy | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Triglycerides (TG) | Part of conventional lipid profile | Change from start of trial (time of randomization) through end of trial (12 months) | 
| High-density lipoprotein cholesterol (HDL-C) | Part of conventional lipid profile | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Low-density lipoprotein cholesterol (LDL-C) | Part of conventional lipid profile | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Glucose | Measured enzymatically using hexokinase method | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Insulin | Measured by electrochemiluminescence immunoassay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Insulin resistance | Measured by homeostasis model assessment (HOMA), using fasting glucose and insulin concentrations | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Adiponectin - total and high molecular weight | Hormone released from fat cells, promotes insulin sensitivity and helps regulate blood glucose, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Hemoglobin A1c (HgA1c) | Marker of blood glucose control, measured using a system based turbidimetric immunoinhibition | Change from start of trial (time of randomization) through end of trial (12 months) | 
| High-sensitivity C-reactive protein (hsCRP) | Indicator of chronic inflammation, measured by immunoturbidimetric assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Interleukin-6 (IL-6) | Protein which stimulates synthesis of hsCRP, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Fibrinogen | Protein involved in blood clotting, measured by immunoturbidimetric assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Plasminogen activator inhibitor-1 (PAI-1) | Protein involved in blood clotting, measured by ELISA assay | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Systolic blood pressure | Measured by auscultation | Change from start of trial (time of randomization) through end of trial (12 months) | 
| Diastolic blood pressure | Measured by auscultation | Change from start of trial (time of randomization) through end of trial (12 months) |