Doctoral CRP on Longitudinal Measures of Body Composition of Healthy Infants and Young Children up to 2 Years of Age Using Stable Isotope Techniques

The double burden of malnutrition presents a significant global health concern, especially in low- and middle-income countries where high levels of undernutrition remain in addition to increasing obesity levels. The first years of life are recognized as a priority in establishing strong nutrition foundations to ensure optimal growth and functional development, as well as long-term health. Policies and programs to improve feeding practices and food quality in early life are essential for preventing malnutrition across the life course. Infant and young child feeding interventions must be informed by accurate, informative, and relevant data. To promote effective early-life interventions and understand the associations between early-life nutrition and later health, it is important to capture the nutritional status of infants through the collection of body composition data [1]. Although length and weight are core components of early childhood global nutrition surveillance, these measurements (and derivatives, such as BMI) do not provide information on FM and FFM. Body composition has important implications for energy metabolism and long-term health. The literature has highlighted the need for the assessment of body composition in infants [1,2] and assessment techniques have become more accessible; however, the lack of available reference body composition data has been a key barrier to the implementation of these techniques in public health or clinical settings. Body composition can be challenging to assess in infants and young children, although several techniques are available, which have been shown to be feasible and accurate in children aged <2 y. The “PEA POD” uses air displacement plethysmography (ADP) to assess body composition from birth up to 6 mo of age, and is a simple, noninvasive, and quick technique that can be used in public health and clinical settings. Deuterium dilution (DD) can be used to accurately determine total body water (TBW) in the field, which makes it a feasible technique with wide applicability for assessing the body composition of infants. To ensure that body composition data from these techniques are valuable for public health guidance as well as clinical evaluation, reference data are needed. We developed body composition reference curves between birth and 24 mo, which will allow the body composition to be evaluated over the first 2 y of life. We combined longitudinal data from 4 regions (Africa, Asia, Oceania, and South America) and collected data matching the MGRS eligibility criteria and harmonized protocols across all countries. The longitudinal data collected on healthy infants with >5500 measurements represent the most diverse collection available of body composition data across the first 24 mo. Now with the reference data available, clinicians and researchers have the tools to evaluate and interpret body composition measurements to inform and evaluate interventions to combat the double burden of malnutrition and setup healthier childhood trajectories.