Trans fat is one of the four fatty acid groups in the diet, and among them it is the only group limited on its own with an upper limit. The limit given by Türkiye Beslenme Rehberi (TÜBER), Türkiye's national dietary guideline, is clear: the dietary intake of trans fats should be less than 1 percent of daily energy. In a 2000 calorie diet this corresponds to 20 calories, that is about 2 grams a day.
Where is it found?
The sources come from two arms. Those formed naturally are found in small amounts in beef, lamb and goat meat and in milk products. Those produced industrially are found more densely in ready-made foods, in flour-based products, in fried foods, in supermarket products and in products such as ready-made popcorn.
A second source group is the state of the fat itself: semi-solid and partially hydrogenated liquid oils, and some margarines. Here the guideline notes a positive development as well: with the changes in production technology, soft tub margarines contain very little trans fatty acid or none at all.
What does the cooking method change?
Trans fat does not stay only in the product that is bought; it can rise in the kitchen too. The guideline states that reheating a food containing trans fat even at a low level, again and again, can lead to a rise in that amount, and asks that attention be paid to cooking methods.
The practical equivalent of the same warning shows in preparing food: trans fatty acid intake rises with the consumption of various flour-based foods that are fried or prepared in the oven. So holding the limit has to do not only with reading labels but with the cooking choice as well. In the same section it is asked that boiling, grilling and oven cooking methods be used in preparing meat, and that frying be avoided.
Why such a narrow limit?
The guideline explains the reason over blood lipids. Trans fatty acids raise low density lipoproteins, that is LDL, and lower high density lipoproteins, that is HDL. This two-way effect is the reason the group is limited with a separate ceiling.
In the nutrient table prepared for worker nutrition the wording is sharper still. There is no number on the trans fatty acid line; the line carries only the statement its consumption is not recommended. While all the other items there carry a ratio or an amount, this line shows a direction.
How is the limit held in practice?
The first step is to lower the source: ready-made flour products, fried products and ready-made snacks. The second step is to move from solid fat to liquid oil; the guideline recommends that soft margarines and spreadable fats be preferred over hard margarines.
The third step is in the kitchen. Boiling, grilling and oven cooking are chosen instead of frying; fat is added to the dish without being burned. Not using the same oil for frying again and again is the most easily applied item on this list. The fourth step is label comparison: the guideline shows looking at the labels of similar products and choosing the one whose fat ratio is lowest as one of the easiest ways.
Its place among the four fat types
To understand trans fat the other three groups have to be put side by side with it as well. The fats in the diet are divided into four groups as monounsaturated, polyunsaturated, saturated and trans fatty acids; the fat composition in foods is made up of a mixture of these four.
The targets the guideline gives to the other three groups are written with numbers: of the energy coming from total fat, 10 percent should come from saturated, 12-15 percent from monounsaturated and 7-10 percent from polyunsaturated fats. Trans fat takes no share inside this distribution; a ceiling is put over it.
The frame is inside the total fat target: 20-35 percent of daily energy comes from fat. In a 2000 calorie diet this comes to 44-77 grams of fat, and the roughly 2 gram ceiling calculated for trans fat stays inside that total.
Where does it turn into a mistake?
The first mistake is identifying trans fat with margarine alone; today most soft margarines contain very little of this group or none at all, while fried ready-made products go on being a source. The second mistake is counting naturally formed trans fat on the same scale as the industrial kind; the guideline states that the first is found in small amounts in meat and milk products.
The 1 percent ceiling is a population measure; it is not converted from this article into a personal target. This content has been prepared to support general nutrition literacy; it does not take the place of medical diagnosis or treatment and does not carry the character of personal nutrition advice. A personalized plan is prepared only by a qualified dietitian; if there is pregnancy, chronic illness, regular medication use, child nutrition or a clinical condition, supervision by a doctor and a dietitian is required before starting a plan.