Frying

Frying is the cooking of food in oil or another fat. Similar to sautéing, pan-fried foods are generally turned over once or twice during cooking to make sure that the food is evenly cooked, using tongs or a spatula, whilst sautéed foods are cooked by "tossing in the pan". A large variety of foods may be fried.
Frying is believed to have first appeared in the Ancient Egyptian kitchen, during the Old Kingdom, around 2500 BC. Around the Middle Ages, fried food became a common delicacy for wealthy people, with fried meats and vegetables becoming popular dishes.
It is believed that frying was created, and used, as a way to preserve food.
Unlike water, fats can reach temperatures much higher than 100 °C (212 °F) before boiling. This paired with their heat absorption properties, neutral or desired taste, and non-toxicity, makes them uniquely valuable in cooking, especially frying. As a result, they are used in a wide variety of cuisines.
Through frying, one can sear or even carbonize the surface of foods while caramelizing sugars. The food is cooked much more quickly and has a characteristic crispness and texture. Depending on the food, the fat will penetrate it to varying degrees, contributing richness, lubricity, its own flavour, and calories.
Frying techniques vary in the amount of fat required, the cooking time, the type of cooking vessel required, and the manipulation of the food. Sautéing, stir-frying, pan frying, shallow frying, deep frying, and air frying are all standard frying techniques.
Pan-frying, sautéing, and stir-frying involve cooking foods in a thin layer of fat on a hot surface, such as a frying pan, griddle, wok, or sautee. Stir frying involves frying quickly at very high temperatures, requiring that the food be stirred continuously to prevent it from adhering to the cooking surface and burning.
Shallow frying is a type of pan frying using only enough fat to immerse approximately one-third to one-half of each piece of food; fat used in this technique is typically only used once. Deep-frying, on the other hand, involves totally immersing the food in hot oil, which is normally topped up and used several times before being disposed of. Deep-frying is typically a much more involved process and may require specialized oils for optimal results.
Deep frying is now the basis of a very large and expanding worldwide industry. Fried products have consumer appeal in all age groups and in virtually all cultures, and the process is quick, can easily be made continuous for mass production, and the food emerges sterile and dry, with a relatively long shelf life. The end products can then be easily packaged for storage and distribution. Some include potato chips, French fries, nuts, doughnuts, and instant noodles.
A 2021 meta-analysis found that the highest category of fried food consumption compared to the lowest is associated with a 3% increase in the risk of all-cause mortality, as well as with a 2% increase in the risk of cardiovascular mortality. Compared to participants with a low intake, those who ate the most fried food had a 37% increased risk of heart failure, a 28% increased risk of major cardiovascular events, and a 22% increased risk of coronary heart disease. The risk of stroke, heart failure, and heart attack modestly increased with the increase of weekly servings of fried food. The study concluded that fried food consumption may increase the risk of cardiovascular disease and presents a linear dose-response relation. The researchers theorized the main reasons behind these associations are the high trans fat and calorie content of fried foods and their pro-inflammatory nature. It was also noted that eating hyperpalatable crisp-fried foods may entice people to engage in routine overeating.
A 2023 meta-analysis found that fried food consumption is linked to a 52% increase in the risk of stomach cancer. Fried food intake is also associated with prehypertension, hypertension and obesity.