A 28-year-old woman with a history of pulmonary tuberculosis (on anti-TB drugs for 2 months) presents to the outpatient department with fatigue, weight loss of 8 kg over 4 months, and poor dietary intake due to loss of appetite. On examination, BMI is 16.5 kg/m² (previously 21 kg/m²), and she has mild muscle wasting. Serum albumin is 3.2 g/dL, and haemoglobin is 9.8 g/dL. She is clinically stable and able to eat normally. What is the most appropriate immediate next step in management?