Child wasting and concurrent stunting in low- and middle-income countries
Authors: Mertens Andrew , Benjamin-Chung Jade , Colford John M. , Hubbard Alan E. , van der Laan Mark J. , Coyle Jeremy , Sofrygin Oleg , Cai Wilson , Jilek Wendy , Rosete Sonali , Nguyen Anna , Pokpongkiat Nolan N. , Djajadi Stephanie , Seth Anmol , Jung Esther , Chung Esther O. , Malenica Ivana , Hejazi Nima , Li Haodong , Hafen Ryan , Subramoney Vishak , Häggström Jonas , Norman Thea , Christian Parul , Brown Kenneth H. , Arnold Benjamin F. ,   The Ki Child Growth Consortium, Ahmed Tahmeed , Ali Asad , Begín France , Bessong Pascal Obong , Bhutta Zulfiqar A. , Black Robert E. , Bodhidatta Ladaporn , Checkley William , Crabtree Jean E. , Das Rina , Das Subhasish , Duggan Christopher P. , Faruque Abu Syed Golam , Fawzi Wafaie W. , da Silva Filho José Quirino , Gilman Robert H. , Guerrant Richard L. , Haque Rashidul , Houpt Eric R. , Iqbal Najeeha Talat , John Jacob , John Sushil Matthew , Kang Gagandeep , Kosek Margaret , Lima Aldo Ângelo Moreira , Mahopo Tjale Cloupas , Manandhar Dharma S. , Manji Karim P. , Mduma Estomih , Mohan Venkata Raghava , Moore Sophie E. , Nyathi Mzwakhe Emanuel , Olortegui Maribel Paredes , Petri William A. , Premkumar Prasanna Samuel , Prentice Andrew M. , Rahman Najeeb , Sadiq Kamran , Sarkar Rajiv , Saville Naomi M. , Shrestha Bhim P. , Shrestha Sanjaya Kumar , Sonko Bakary , Svensen Erling , Syed Sana , Umrani Fayaz , Ward Honorine D. , Yori Pablo Penataro 
Published: September 2023

Sustainable Development Goal 2.2—to end malnutrition by 2030—includes the elimination of child wasting, defined as a weight-for-length z-score that is more than two standard deviations below the median of the World Health Organization standards for child growth1. Prevailing methods to measure wasting rely on cross-sectional surveys that cannot measure onset, recovery and persistence—key features that inform preventive interventions and estimates of disease burden. Here we analyse 21 longitudinal cohorts and show that wasting is a highly dynamic process of onset and recovery, with incidence peaking between birth and 3 months. Many more children experience an episode of wasting at some point during their first 24 months than prevalent cases at a single point in time suggest. For example, at the age of 24 months, 5.6% of children were wasted, but by the same age (24 months), 29.2% of children had experienced at least one wasting episode and 10.0% had experienced two or more episodes. Children who were wasted before the age of 6 months had a faster recovery and shorter episodes than did children who were wasted at older ages; however, early wasting increased the risk of later growth faltering, including concurrent wasting and stunting (low length-for-age z-score), and thus increased the risk of mortality. In diverse populations with high seasonal rainfall, the population average weight-for-length z-score varied substantially (more than 0.5 z in some cohorts), with the lowest mean z-scores occurring during the rainiest months; this indicates that seasonally targeted interventions could be considered. Our results show the importance of establishing interventions to prevent wasting from birth to the age of 6 months, probably through improved maternal nutrition, to complement current programmes that focus on children aged 6–59 months.