The effect of the cooking fat and the dining table fat on the dietary composition of fatty acids and vitamin D content

The purpose of the project was to study possible effects of fats used in cooking
and at the dining table on the nutritional quality of the diet, focusing on composition
of fatty acids and the content of vitamin D. The background of the project
was in part the dietary advice of the Swedish National Food Agency to use liquid
margarine or oils in cooking and in part the fact that liquide and hard margarine is
used as the standard fat in when calculating the nutritional content of composite
foods in the NFA food database. The nutritional values in the food composition
database are among other things used to calculate nutrient intake in Swedish dietary
surveys. It is therefore important for future dietary studies to know if and how
the results are affected by the use of a standard fat in the recipes in the database
instead of using the cooking fats the participants actually use. It is also important
for the NFA’s work with dietary advice to evaluate if the advice regarding cooking
fats has any effect on the fatty acid composition of the diet.
Data from the latest, Swedish dietary survey, Riksmaten vuxna – 2010-11, was
used to study the effect which the choice of fat used in cooking and at the dining
table makes on nutritive intakes. The margarine-products that were used as the
standard cooking fat in recipes were substituted for canola oil, olive oil, butter and
margarine in different combinations. The table fats that were reported in the dietary
survey were substituted for butter, a common type of fat blend and a fat
spread containing a higher amount of polyunsaturated fatty acids, a lower amount
of saturated fatty acids and a high content of vitamin D due to fortification, compared
to the other table fats used.
Cooking fat constituted on average 10 procent of the total fat intake and table fats
constituted 8 procent.The results showed significant differences in total fatty acid
composition and intake of vitamin D when using different types of fat. Canola oil
was the cooking fat that gave the best fatty acid composition, but at the same time
it lowered the intake of vitamin D compared to the margarine that is normally
included in the recipes. Combinations of cooking fats and table fats were studied
and the best nutritive values were achieved with a combination of liquid margarine
and the fat spread that contained the highest amount of polyunsaturated fatty
acids, the lowest amount of saturated fatty acids and had a high content of vitamin
D. The use of only butter in cooking and at the dining table had the largest negative
impact on nutritional quality out of the fats that were included in the study.