Rethinking Saturated Fat

One of the most common warnings in dietary guidelines worldwide is to avoid saturated fat. However, there is no clear definition of what a saturated fat is. There are four definitions that have been used to describe saturated fat: amount of saturated fatty acids in grams per 100 grams, % fatty acid profile, iodine value, and solid fat. The current description of “saturated fat” does not distinguish between fats and oils, which are mainly triglycerides of fatty acids, and whole food items, which contain proteins and minerals and much lower amounts of triglycerides. Secondly, the current classification of saturated fat ignores the difference in the cholesterol content of vegetable oils and animal fats. The first definition of saturated fat was based on iodine values which does not give fatty acid composition. This classification is still used today by various dietary guidelines. The use of solid fat as a defining property of saturated fat is based on the melting of a fat at room temperature. This is not scientifically precise. This paper discusses the confusion due to the multiple definitions of saturated fat. The following are proposed to overcome this situation: first, fats and oils and animal-derived whole food items should be considered in separate categories based on their lipid content; second, the saturated fatty acid composition measured in grams per 100 grams (g/100 g) should be used as the basis for classifying fats and oils as saturated fat; and third, a new category of meso-fat is proposed.