Assessing early growth and adiposity: report from an EarlyNutrition Academy workshop

This report provides a summary of a workshop organised by the European Commission-funded EarlyNutrition Project and the EarlyNutrition Academy. Accurate and reliable methods to assess body composition are needed in research on prenatal and early post-natal influences of nutrition on later health because common surrogate measures of maternal and offspring adiposity (body fat content), such as body mass index (BMI), have relatively poor predictive power for the risk of later disease. The key goals of the workshop were to discuss approaches to assess growth and body composition from pregnancy to adolescence, to summarise conclusions and to prepare a framework for research in the EarlyNutrition Project. The participants concluded that there is a pressing need to harmonise the methodologies for assessing body composition, recognising that each has advantages and limitations. Essential core measurements across studies assessing early growth and body composition were identified, including weight, length, BMI, waist and mid-upper arm circumference, subscapular and triceps skinfold thicknesses, and bioelectrical impedance analysis. In research settings with access to more sophisticated technologies, additional methods could include dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, ultrasound assessment of regional body fat, magnetic resonance imaging (MRI), air displacement plethysmography (ADP), and deuterium dilution. These provide richer data to answer research questions in greater depth but also increase costs. Where overall whole-body composition is the primary outcome measure, ADP or tracer dilution should be used whenever possible. Where regional distribution of body fat is of greater interest, an imaging technique such as MRI is preferred.