'Severe malnutrition': thinking deeplyS, communicating simply.

### Summary box Malnutrition affects millions worldwide and underlies almost half of deaths in children aged <5 years.1 Progress towards Sustainable Development Goal 2 (End hunger) was already slow but coronavirus-related secondary impacts now threaten nutritional crises described as: Biblical, on steroids, across generations .2 Towards effective actions, effective communication matters. Malnutrition involves a plethora of complex technical terminology. Sometimes it helps to go beyond details and consider problems at broader scale, especially when engaging with non-specialist stakeholders like policymakers, funders and the public. These may not wish to know full technical nuances, but they should: Focusing on undernutrition, we argue that a simple umbrella term, ‘Severe Malnutrition’ would benefit future communication and advocacy efforts. Defining a problem is vital for effective action/evaluation. Assessing both individual and population nutritional status typically involves anthropometry.3 Measurements (eg, weight) are interpreted through indices (eg, weight-for-age) in comparison with reference populations (eg, WHO Growth Standards, a ‘gold standard’ describing how healthy children should grow). Current terminology is summarised below.1 Often neglected is the full definition of malnutrition: ‘Any condition in which deficiency, excess or imbalance of energy, protein or other nutrients…adversely affects body function and/or clinical outcome’.4 Problems consequently arise. ### Undue focus on body size Being severely small (short or thin) alone …