Human Milk Sampling Protocols: Is the Mean Macronutrient Composition of Pre- and Post-Feed Samples the Average of One Entire Feed?

For the fat concentration, none of the three sub-sampling protocols was accurate. The mean of pre- and post-feed samples could, however, be used for high-fat milk samples where measurement errors exceed the bias (+0.3 g/dl). Pre-feed or post-feed samples only should not be used to estimate the fat concentration of a complete feed. For proteins and carbohydrates, one milk sample taken at any moment in a breastfeed is sufficient to represent the concentration in the complete feed.