Nutritional Assessment

Core Concepts

Screening vs. comprehensive assessment

• Screening is quick, routine, and done on everyone — at admission and at intervals during a stay. It uses simple data (recent weight change, appetite, intake, diagnosis, age, risk factors) to flag patients needing a full evaluation. Tools vary by facility; the nurse uses the facility's chosen one.
• Comprehensive assessment is the detailed evaluation for patients who screen positive or are known to be at risk. Usually dietitian-led, it includes diet history, anthropometrics, physical exam, lab review, and functional assessment, producing the nutrition diagnosis and care plan. The nurse's role: collect accurate data, screen, refer.

The nutrition-focused health history

The history turns the patient's story into usable data:

• Diet history: usual foods, meal patterns, recent changes.
• 24-hour recall: everything eaten and drunk in the last day (remembering that memory is imperfect).
• Food frequency: how often certain foods are eaten — catches one-sided diets.
• Weight history: usual weight, recent unintentional gain or loss, and over what period.
• Risk-factor review: illnesses, surgeries, medications, chewing/swallowing problems, dental issues, allergies, substance use, and the socioeconomic/cultural factors from the previous topic.
• Functional and social context: who shops and cooks, whether the patient can feed themselves, whether help is available.

The nurse asks conversationally and nonjudgmentally — patients often under-report or feel ashamed about eating, so trust is part of the data.

Anthropometric measures

• Height and weight are the minimum; they must be measured (never guessed) and repeated so trends are visible. A single weight is a snapshot; a series is a story.
• Body mass index (BMI) — weight relative to height — is a convenient screening number, but only a screening number: it does not distinguish muscle from fat, says nothing about recent change, and can misclassify athletes or older adults with muscle loss.
• Other measures in fuller assessments (waist circumference, skinfolds) are technique-dependent and done by trained staff.

Physical signs and functional assessment

Nutrition problems write themselves on the body, though few signs are specific to a single deficiency: poor skin, brittle hair and nails, sore gums, a smooth tongue, poor wound healing, muscle wasting (temples, hands, thighs), and edema can reflect or accompany poor nutrition. They overlap with other illnesses, so they are supporting clues, not diagnoses.

Functional assessment asks what the patient can actually do: chew? swallow safely? reach the tray? feed themselves? sit up to eat? A patient who cannot physically eat will not be nourished no matter how good the diet order is — mealtime observations (how much is eaten, coughing with meals, fatigue) become assessment data.

Laboratory data

Laboratory values — markers of protein status, anemia, or organ function — add another piece, but must be interpreted with the clinical picture. Labs are affected by inflammation, hydration, medications, and other conditions, so a number alone neither proves nor disproves malnutrition. Reference ranges vary by lab and institution; interpretation belongs to the provider and dietitian. The nurse's job: know why tests were ordered, collect specimens correctly, track trends, and report out-of-range values — without diagnosing from a single number.

Putting it together

Assessment ends not in a pile of data but in a conclusion and a plan. The nurse documents findings, identifies at-risk patients, refers them, and works with the team to implement the plan (diet changes, supplements, enteral nutrition, education, follow-up). Reassessment is built in — screen → assess → intervene → reassess repeats through the stay and into discharge planning.

Common Confusions