Peer-reviewed article
Rethinking water, sanitation, and hygiene for human growth and development
Douglas J. Momberg, Lee E. Voth‐Gaeddert, Linda Richter, Shane Anthony Norris, Rihlat Said Mohamed ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This paper argues that water, sanitation, and hygiene (WASH) interventions have been undervalued because evaluations focus too narrowly on linear growth (height and weight). Using life history theory, the authors propose that early childhood conditions trigger adaptive responses where the brain prioritises its energy needs over body growth. They recommend evaluating WASH interventions using age-appropriate developmental outcomes beyond just physical growth, and considering context to design more transformative interventions.
Key points
- Early life conditions have long-term consequences for health and wellbeing through developmental and biological programming
- Undernutrition in early life may trigger adaptive mechanisms that prioritise brain growth over body growth
- Current emphasis on linear growth as the key metric for WASH intervention efficacy may mask their broader developmental importance
- Life history theory and evolutionary public health perspectives can identify age-appropriate biological outcomes and WASH indicators
- Context-integrated approaches are needed to develop transformative WASH interventions
Limitations
This is a theoretical paper proposing a framework rather than presenting empirical data or evaluation results. It does not provide evidence on whether WASH interventions actually improve child development outcomes beyond growth, or demonstrate that the proposed life history approach would yield better intervention design or results.
Abstract
Life history theory emphasises plasticity in developmental and biological programming where conditions in early life, lead to long-term consequences for health and wellbeing. Studies linking water, sanitation, and hygiene, nutrition, and child growth and development have emphasised the optimisation of linear growth as a key metric for the evaluation of intervention efficacy. Life history characteristics pertaining to human growth and phenotypic plasticity, suggest that different developmental outcomes in early childhood may be responsive to different stimuli at different ages. Energy utilisation by the human brain, from birth through childhood, accounts for a disproportionate percentage of the resting metabolic rate. Undernutrition in early life, and its relative resultant energy deficiency, may trigger adaptive physiological mechanisms prioritising brain growth at the expense of body growth. Emphasis placed on linear growth may have impeded the significance of WASH due to excluding aspects of child development beyond height/weight. We propose that incorporating evolutionary public health and life history theory perspectives, allows for the identification of age-appropriate biological outcomes and WASH indicators, while anticipating the timing and life-course suitability of the interventions being operationalised. Finally, integrating reflections regarding context allows for the development of transformative WASH interventions.