A 2-year-old girl from a slum in Delhi is admitted with a 3-month history of poor feeding, recurrent diarrhea, and swelling of the face and legs. On examination, she weighs 8 kg (expected: 12 kg), appears apathetic and withdrawn, and has bilateral pitting edema of the legs and face. Her skin shows a characteristic 'flaky paint' dermatitis over pressure areas. Serum albumin is 1.8 g/dL, total protein is 4.2 g/dL, and hemoglobin is 7.5 g/dL. What is the most appropriate immediate nutritional management for this child?