Final answer:
Diagnostic tests and data that help determine a client's nutritional status include measuring metabolites in blood plasma through chemical assay, analyzing blood samples after giving the client radioactive fatty acids, iron, and vitamin B12, and keeping a food diary.
Step-by-step explanation:
There are several diagnostic tests and data that can help determine a client's nutritional status. One common test is the measurement of various metabolites in blood plasma through chemical assay. This can provide information about the levels of different nutrients in the body. Another test involves analyzing blood samples after giving the client radioactive fatty acids, iron, and vitamin B12 orally to assess the normal function and absorption of the gastrointestinal tract. Additionally, keeping a food diary and recording the nutrient information of consumed foods can also provide valuable data.