Why fats are necessary
For many years fat was seen as the prime suspect in nutrition, and fat-free products filled the shelves in that period. Yet fat is a basic macronutrient with roles the body cannot do without, from building cell membranes to producing hormones.
Short answer
Fats are needed for building cell membranes, producing certain hormones, absorbing vitamins A, D, E and K, and supplying essential fatty acids; at about 9 kcal per gram they are the densest energy source. The issue is not fat itself but its type and amount: the general advice is to bring unsaturated fats to the fore and to avoid trans fat.
What fat does in the body
Fat is not only an energy store. The membrane of every cell is built from fat molecules, and a substantial part of brain tissue is fat. The production of some hormones requires fat. Vitamins A, D, E and K are fat-soluble, so their absorption falls in a fat-free meal, and a spoonful of olive oil on a salad makes the vitamins in the tomato and the greens more usable. In addition, the essential fatty acids the body cannot make, omega-3 and omega-6, can only be obtained from food. These roles explain why very low-fat eating is not a sustainable general strategy.
9 calories per gram: two sides of density
At about 9 kcal per gram, fat carries more than twice the energy of carbohydrate and protein (4 kcal/g). That density is a feature rather than a flaw, but it calls for portion awareness: two tablespoons of olive oil can multiply the calories of a large plate of salad several times over. Fatty foods also add flavour and a sense of satisfaction to a meal. The logic of energy values is explained in the calorie guide.
Types: saturated, unsaturated, trans
- Unsaturated fats: found in olive oil, in nuts such as hazelnuts and walnuts, in avocado and in fish. Dietary guidelines recommend giving this group the greater weight of fat intake, and the omega-3s in fish are singled out as well.
- Saturated fats: found in butter, meat, full-fat dairy products and coconut oil. The general advice is to keep their share of total energy limited rather than to ban them altogether.
- Trans fats: the product of industrial partial hydrogenation; the authorities recommend keeping them at the lowest possible level. As in many countries, industrial trans fats have been restricted in Türkiye.
Reading fat on a label
The fat line in the nutrition table gives the total, and the saturated fat line the saturated part of it. The phrase “partially hydrogenated vegetable oil” in an ingredients list is a sign of trans fat, and it is particularly worth checking the list in products mentioning “hydrogenated” or “vegetable margarine”. Using frying oil over and over also damages the structure of the fat, and not reusing frying oil many times at home is a general recommendation. Remember to make comparisons on a 100 gram basis; the method is explained in the label guide.
Omega-3 and omega-6: the essential pair
Essential fatty acids are the most asked-about part of the subject of fat. Omega-3 and omega-6 are two families of fatty acid that the body cannot produce itself and must therefore take from food; they take part in the structure of cell membranes and in the production of many regulatory molecules in the body. Omega-6 sources such as sunflower oil, corn oil and grains are already plentiful in modern diets, so the side that needs attention is omega-3. Oily fish such as salmon, sardines, anchovies and mackerel are the strongest sources of omega-3; on the plant side walnuts, linseed and purslane stand out, though the conversion of the plant form into active forms in the body is limited. One or two portions of fish a week is a recommendation shared by many dietary guidelines, and small fish such as anchovies and sardines are both economical and easy to find. For people who do not eat fish, talking to a doctor rather than deciding alone whether a supplement is needed is the soundest route.
Balanced use of fat in practice
A workable framework in the everyday kitchen can be set up like this: choose a predominantly unsaturated oil such as olive oil for cooking and salads, make room for fish during the week, leave space for a handful of unroasted nuts or seeds as a snack, use butter sparingly as a flavouring, and compare the saturated fat and trans fat lines on packaged products. If you have a diagnosis of high cholesterol or cardiovascular disease, decisions about the types and amounts of fat should be made together with your doctor and dietitian; the framework here is general information.
Frequently asked questions
Is a fat-free product always better?
No; sugar or starch may be added to products with reduced fat to make up for the loss of flavour. Choosing on the basis of the words “fat free” without looking at the whole label can be misleading.
Is there a difference between olive oil and sunflower oil?
Both are vegetable and predominantly unsaturated, but their fatty acid profiles differ. Extra virgin olive oil also carries components such as polyphenols, and bringing olive oil to the fore in the overall pattern is a common recommendation.
Should I take an omega-3 supplement?
The priority is food-based routes such as eating fish during the week. Whether a supplement is necessary depends on individual circumstances and should be decided in discussion with a doctor.
Should eggs and butter be treated as forbidden?
No; the current approach looks at the overall pattern rather than banning individual foods. Keeping the share of saturated fat in the total limited is more workable than sorting single foods into moral boxes.
This guide draws on the World Health Organization's general recommendations on types of fat and on the framework for fat consumption in the Turkey Dietary Guidelines, the national nutrition guidance published for Türkiye.