2.9 NACS USER’S GUIDE MODULE 2Nutrition Assessment and Classification How to Find BMI-for-Age for Children and Adolescents 5−18 Using Look-up Tables Simple BMI can be used as an indicator of nutritional status in adults who have completed their physical development. However, for adolescents, who are still growing, BMI-for-age z-score is the preferred indicator of body thinness used to classify malnutrition because it considers age and sex. BMI-for-age is recorded as a z-score, measured in standard deviations (SD). A z-score shows how many SD a person’s BMI is away from the median BMI value of the reference population. Materials needed 1.Body mass index (BMI) look-up tables 2.BMI-for-age look-up tables Step 1. Find BMI using the BMI look-up tablesa.Round the client’s height to the nearest cm. Then find the height in the left-hand (vertical) column in the tables. b.Round the client’s weight to the nearest kg. Then find the weight in the bottom (horizontal) row. c.The BMI is the point where the two lines meet. Record the BMI. Step 2. Determine BMI-for-age using the BMI-for-age look-up tables.a.Find the number closest to the child’s age in the appropriate BMI-for-age table (girls or boys). b.Trace your finger across to find the range that contains the child’s BMIthat you found in step 1. c.Trace your finger up to see the nutritional classification of the child..