Final answer:
For a nursing diagnosis of Imbalanced nutrition related to anorexia, nausea, and vomiting, the electrolyte imbalance 'as evidenced by' in the diagnostic statement should be hypokalemia, as it correlates with symptoms that can disturb potassium levels.
Step-by-step explanation:
Nursing Diagnosis and Electrolyte Imbalance
The nursing diagnosis of Imbalanced nutrition: less than body requirements related to anorexia, nausea, and vomiting would logically be tied to indicators of nutritional status and metabolic function. Among the choices given, the most appropriate electrolyte imbalance to use as the "as evidenced by" portion for this nursing diagnostic statement is hypokalemia. This is because hypokalemia is an abnormally decreased blood level of potassium, which can arise from vomiting, diarrhea, or alkalosis - conditions that are consistent with the symptoms of anorexia, nausea, and vomiting.
Therefore, the correct answer is option 2) Hypokalemia as it specifically correlates with the potential consequences of the stated symptoms on electrolyte and nutritional balance within the body.