Fig. 1

Algorithm for tailored enteral nutrition. *Additional amount of fat, protein, and/or carbohydrate required to achieve target levels of macronutrients will be calculated as addition = ESPGHAN recommendations (OMM/HDM + increment by routine fortification). **One-to-one CLC support, followed by weekly lactation re-evaluation. If OMM amount is less than 20 ml/day for ethical reasons, it will not be submitted for analysis and fortification will be continued as per most recent report. To enhance feeding tolerance at the start of the intervention, TF will be gradually introduced in a stepwise manner over a 3-day period (maximum target dosage of added fat, protein, and carbohydrate at day 1 was 0.3 g, day 2 was 0.6 g, and day 3 was 0.9 g per 100 ml breast milk), as suggested by Rochow². On day 4, the full amount of TF for each macronutrient will be prescribed; this day will be marked the starting point of the intervention period. Feeding route and quantity advancement will comply with standard unit protocol