The in vitro digestion models mimicking the gastrointestinal (GI) tract of general population and lipid indigestion patients (with lower levels of bile salts or pancreatic lipase) were selected to investigate whether diacylglycerols (DAGs) are potential good lipid sources for these patients. Linseed oil-based DAG (LD) and linseed oil (LT) were selected. LD-based emulsion ((83.74 ± 1.23)%) had higher lipolysis degree than LT-based emulsion ((74.47 ± 1.16)%) when monitoring the GI tract of normal population as previously reported. Indigestion conditions seriously decreased the digestive degree of LT-based emulsion ((40.23 ± 2.48)%–(66.50 ± 3.70)%) while showed less influence on LD-based emulsion ((64.18 ± 2.41)%–(81.85 ± 3.45)%). As opposed to LT-based emulsion, LD-based emulsion exhibited preference for releasing unsaturated fatty acids (especially oleic acid and α-linolenic acid) due to their different glycerolipid compositions. LD-based emulsion showed potential for providing lipids and nutrients (including essential fatty acids) for lipid indigestion patients.

Diacylglycerol (DAG)-based edible oils have attracted increasing research interest owing to their health-promoting properties. Recent animal and human studies showed that an increased 1,2-DAG content in the liver and skeletal muscle may cause insulin resistance. However, earlier studies using animal models or humans reported that dietary DAGs with a 1,2-DAGs to 1,3-DAGs ratio of approximately 3:7 could improve insulin sensitivity in type 2 diabetic patients. This conflict raises the question of whether there is a link between the ingested DAGs and endogenous DAGs during their metabolism. To make a contribution to this field, this review provides an overview of the metabolic pathways of ingested DAGs and biological roles of DAGs (ingested and endogenous) in the change of insulin sensitivity. Accordingly, strategies for further investigations on the metabolism of DAGs are proposed.