Provided is a method of preparing a nutritional formula comprising long chain-polyunsaturated fatty acids (LC-PUFAs) in the form of monoglycerides and free fatty acids prior to ingestion by a subject comprising exposing a liquid nutritional composition comprising LC-PUFA triglycerides and/or LC-PUFA esters to a lipase. Further provided is a nutritional formula prepared by this method, and its use for providing nutrition, for improving fat absorption, for improving cognitive ability, for preventing chronic lung disease, and for reducing the length of time a patient requires total parenteral nutrition. Additionally provided are devices comprising immobilised lipases useful in the method of preparation.
