Measurement of Energy Metabolism in Infants

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to measure energy expenditure during the first 3 months of life in infants.

Detailed Description
-----------------
This study intends to establish the feasibility of undertaking comprehensive metabolic phenotyping in infants. The overarching aim is to complete a prospective assessment of energy expenditure in the new infant metabolic chamber approximately one week apart to determine the accuracy and precision of infant protocols related to energy metabolism (sleeping metabolic rate, resting metabolic rate, diet-induced thermogenesis) and physical activity. This cross-sectional study will answer the following questions: What is the test re-test reliability of measuring energy expenditure (sleeping metabolic rate, resting metabolic rate, diet-induced thermogenesis) in an infant under the same conditions, 5-7 days apart? What is the reliability of 24h energy expenditure estimated by the infant metabolic chamber in comparison to a 7-day doubly labeled water study? How do energy expenditure measurements in infants need to be adjusted to account for variability in infant size and body composition?

Official Title
-----------------
Measurement of Energy Metabolism in Infants: BabyEE Pilot

Conditions
-----------------
Infant Development, Infant Overnutrition

Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy, full-term infant Aged 1 month (28 days) to 3 months (12 weeks, 6 days) at the first visit Exclusively fed breast milk and/or infant formula Willing to accept doubly-labeled water Exclusion Criteria: Unable to complete 3 clinic visits within about 14 days at Pennington Biomedical Research Center Born preterm (< 37 weeks gestation) Congenital abnormality or disability Gastric reflux Acute illness within 7 days of the study (fever, diarrhea) Use of medications to treat a chronic condition (does not include use of vitamin supplements or PRN medication for flatulence or reflux such as Pepcid)

Ages Eligible for Study
-----------------
Minimum Age: 1 Month
Maximum Age: 3 Months

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Infants<br>Infants aged 1-3 months | |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Energy Expenditure by infant metabolic chamber | Energy expenditure by infant metabolic chamber measured twice about 1 week apart for test re-test reliability in infants aged 1-3 months. | Approximately 1 week | 
| Energy expenditure by doubly labeled water | Energy expenditure by doubly labeled water measured over 7 days in infants aged 1-3 months | Approximately 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Percent body fat | Percent body fat by PEA POD measured twice about 1 week apart for test re-test reliability in infants aged 1-3 months. | Approximately 1 week | 
| Physical activity counts | Physical activity counts by Actigraph accelerometer measured over 7 days in infants aged 1-3 months. | Approximately 1 week |