Appetite assessment in severe acute malnutrition management: A narrative review

Severe acute malnutrition (SAM) remains a major global health issue with life-threatening consequences if untreated, and progress is needed in its prevention, diagnosis, and treatment. Appetite tests are widely used in SAM management to determine whether a child requires inpatient or outpatient care, as well as to guide treatment progress and discharge decisions. However, current appetite assessment methods lack standardisation and their reliability is questionable. 

Given the limited number of published studies on the use of appetite assessments in children with SAM, the authors undertook a broader review and examined existing research and guidelines on this topic. The ‘appetite test’ as recommended by World Health Organization (WHO) and national guidelines is done by directly observing a child’s ability to eat ready-to-use therapeutic food (RUTF). If a child with SAM fails the appetite test or has medical complications, they are referred for inpatient care. During treatment, appetite is monitored regularly; if it remains poor, alternative interventions are implemented to support recovery. However, appetite loss in SAM can have multiple causes, including illness, nutrient deficiencies, stress, metabolic changes, and gut health issues. 

Despite the loss of appetite being clinically observed in almost all malnourished children, the exact mechanisms causing appetite loss in these children are still not well understood. Some studies suggest that poor appetite may be linked to disruptions in hormonal regulation, micronutrient deficiencies, or changes in the gut microbiome. Although appetite tests are often used as a proxy for disease severity, at least one study reviewed found no clear link between appetite test results and clinical complications. This suggests that the current appetite test lacks predictive accuracy for identifying children with complicated SAM. 

Despite its limitations, the ‘appetite test’ is the only assessment method recommended by WHO and national SAM guidelines. Yet it is subjective, unreliable, and time-consuming, as many factors besides appetite can affect a child’s willingness to eat. Misinterpreting test results could lead to unnecessary hospital admissions, adding financial strain to health systems and families. Given these weaknesses, the authors argue there is an urgent need to develop a new, objective appetite assessment tool for SAM.

The literature review identified 12 alternative appetite assessment tools, including a parent-rated appetite and satiety tool used in Bangladesh and a short eating behaviour scale tested in children under two years old. However, some tools were developed in high-income settings, and many have not been validated in malnourished children. Further, some methods, such as meal observations, are impractical in low-resource settings. The difficulty in distinguishing “liking” versus “wanting” food in children with SAM, who also often have apathy or irritability, is another challenge.

More high-quality research is needed to create a validated, standardised appetite assessment tool that meets clinical needs in low-resource settings. Future studies should focus on adapting existing tools for practical use, ensuring they are simple, reliable, and effective in guiding SAM management.