Nutrition Assessment and Diagnosis
What to know
Assessment is the systematic collection and interpretation of data to reach a nutrition diagnosis using the PES (Problem, Etiology, Signs/Symptoms) format. Know the components of the nutrition care process (assessment, diagnosis, intervention, monitoring/evaluation) and the domains of nutrition diagnosis (intake, clinical, behavioral-environmental). Understand anthropometry (BMI, waist circumference, weight change), biochemical data, clinical signs, dietary intake methods (24-hour recall, food frequency, food records), and their strengths and limitations. Recognize malnutrition screening and assessment tools and the difference between screening (identifies risk) and assessment (establishes diagnosis).
Traps
Questions often blur screening vs assessment, or ask which intake method is most valid for a given purpose (FFQ for habitual intake in epidemiology; 24-hour recall for low respondent burden but high day-to-day variability). Watch for BMI limitations (does not distinguish muscle from fat; adjust for ethnicity and age). Another trap is mislabeling a PES statement-etiology must be the cause, not a restatement of the problem.
Rule of thumb
Build a PES statement as: Problem (diagnostic label) related to Etiology (cause) as evidenced by Signs/Symptoms (data). If the etiology is missing or circular, the statement is wrong.
Worked example
"Overweight related to excessive energy intake as evidenced by BMI 28 and 24-hour recall showing intake above estimated needs" is correct. "Overweight related to obesity" is circular and incorrect.