Background: The impact of milk banking processes on macronutrient variability in donor human milk (DHM) is largely unknown. Objective: To gain a better understanding of fat and protein composition in DHM and assess potential relationships with modifiable milk bank processes. Methods: Samples of raw, pooled DHM were collected from 20 milk banks (n?=?300) along with the following processing attributes: if macronutrient analysis was used to select donors for pooling (target pooling; yes/no), number of donors per pool, pooling container material (glass/plastic/other), and method for mixing during bottling (manual/mechanical). Fat and protein were assessed. Homoscedasticity was assessed and magnitude of the spread was quantified. Results: Fat ranged from 1.9 to 6.1?g/dL (n?=?298) and protein ranged from 0.7 to 1.4?g/dL (n?=?300). Variability in fat was significantly lower in samples that had been target pooled (p?=?0.04), contained more donors per pool (p?
