Final answer:
Weight loss is a clear indication that a nurse should increase the client's nutritional intake for a client with HIV, as it's a common symptom of worsening illness.
Step-by-step explanation:
A nurse should identify weight loss as an indication to increase the client's nutritional intake when assessing a client who has HIV. Weight loss is a common symptom of AIDS and the illness generally, which often includes wasting syndrome where the patient loses weight rapidly. Providing adequate nutrition is essential to help maintain the patient's energy and body mass, potentially slowing the progression of the illness.