ABSTRACT
Lipids in the human diet derive from the storage and structural lipids of plants and animals. More than 90% of dietary lipids are triacylglycerols originating from the adipose tissue or milk of animals or from plant seed oils, mainly in the form of manufactured products. Seed oils and animal storage fats provide the bulk of the lipids consumed in foods. However, some foods, although contributing little total fat to the diet, are nevertheless important sources of specific essential fatty acids. Lipid digestion in adults takes place mainly in the upper part of the small intestine. Hydrolysis of triacylglycerols catalyzed by the enzyme pancreatic lipase generates fatty acids and mono-acylglycerols. Most naturally occurring fatty acids of dietary significance have double bonds in the cis geometrical configuration. The way in which fatty acids are distributed in a triacylglycerol may also influence plasma cholesterol irrespective of the overall composition of the fatty acids, and this may explain some apparent anomalies.
