Many Chinese people know little about trans fats. Therefore, Yang Yuexin and Fan Zhihong have commented on several common misconceptions. 1. Are all oily things high in trans fats?
No. The formation of trans fats mainly comes from the following three sources: 1. Formed from the solidification of liquid vegetable oil. 2. During high-temperature heating, light, heat, and catalysts cause the fats in vegetable oil to isomerize into trans fats. 3. Occurs naturally in the stomachs of ruminants like cattle, meaning products such as milk and beef contain trace amounts of trans fats. Therefore, unheated vegetable oils do not contain trans fats. 2. Will oils without trans fats produce them after being heated?
Yes. When heated at high temperatures or for extended periods, oils rich in monounsaturated or polyunsaturated fatty acids (such as soybean oil, safflower oil, etc.) are more prone to producing trans fats—because unsaturated fatty acids are "active" and easily oxidized. These oils are suitable for cold salads, stewing, or quick stir-frying where no smoke is produced. When cooking at home, heat the oil until it's about 70% hot; don't wait until it smokes before cooking food. For fried foods, consider using more saturated fats like lard or palm oil. In addition, repeatedly heating oil produces more trans fats, so fried oil cannot be reused and must be discarded. 3. Is it possible to completely avoid consuming trans fatty acids?
Yes. Because the amount of trans fats in natural foods is minimal. The trans fats in dairy products and beef and mutton account for only a fraction of a percent of their total fat content, which normally doesn't reach a level of more than 2 grams per day. If oil is cooked at low temperatures for a short time, the resulting trans fats are also minimal and can be basically ignored. A person can stay away from trans fats by living a healthy life: using fresh oils, rarely frying at high temperatures, eating more salads and stewed dishes, cooking fresh meals at home, and avoiding all kinds of processed foods.