How many levels of undernutrition are defined by the Waterlow criteria?

• A. 2
• B. 3
• C. 4
• D. 5

Answer: (C)

Waterlow criteria separate undernutrition into four levels by using anthropometric measurements and the presence of edema to gauge severity. Mild undernutrition means slight deficits, moderate is more pronounced, severe indicates substantial undernutrition, and very severe (edematous) malnutrition is the most critical category, with edema signaling an urgent need for intensive care. Edema automatically places a child in the most severe category, reflecting the high risk and treatment needs. This four-tier approach gives more nuance than simpler schemes and guides the intensity of nutrition support accordingly.