Body composition (the proportion of fat and lean tissue) in early life is associated with risk of non-communicable diseases in later life. Body composition in infants can be assessed using stable isotope techniques.
The overall objective of the CRP is to assess longitudinal changes in body composition (fat mass and fat free mass) of healthy infants and young children during the first 2 years of life.
To assess longitudinally body composition of healthy young children by stable isotope techniques at 3, 6, 9, 12, 18 and 24 months of age;
To contribute to capacity building in nutrition by supporting PhD students
Body composition assessment in the first 2 y of life provides important insights into child nutrition and health. The application and interpretation of body composition data in infants and young children have been challenged by a lack of global reference data.
We developed body composition reference charts of infants aged 0–6 mo based on air displacement plethysmography (ADP) and those aged 3–24 mo based on total body water (TBW) by deuterium dilution (DD). Body composition was assessed by ADP in infants aged 0–6 mo from Australia, India, and South Africa. TBW using DD was assessed for infants aged 3–24 mo from Brazil, Pakistan, South Africa, and Sri Lanka. Reference charts and centiles were constructed for body composition using the lambda–mu–sigma method.
Sex-specific reference charts were produced for FM index (FMI), FFM index (FFMI), and percent FM (%FM) for infants aged 0–6 mo (n = 470 infants; 1899 observations) and 3–24 mo (n = 1026 infants; 3690 observations). When compared with other available references, there were observable differences but similar patterns in the trajectories of FMI, FFMI, and %FM. These reference charts will strengthen the interpretation and understanding of body composition in infants across the first 24 mo of life. The pooled CRP results also showed that birth weight and breastfeeding are independent predictors of body composition in early life, irrespective of sex. These are important considerations when interpreting data and planning global programs to improve early life nutrition.
This CRP brought together scientist from 6 countries who collaborated and exchanged knowledge to generate important new information on the body composition of infants and generate new tools for clinicians to use in the evaluation of infant health. These results have already been widely disseminated through more than 15 peer reviewed publications and international presentations. This CRP inspired a regional Asian project (RAS6092) and a regional Latin American and Caribbean project (RAS6079) which collected cross sectional infant data to understand regional difference and influences in infant body composition. These 2 regional TC projects are using the CRP developed body composition references curves to evaluate the data from their regions. This CRP has also influenced the IAEA recommended protocol for assessing body composition by deuterium dilution in infants which is now being disseminated through the TC projects.
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.