Lipids represent a major component of food and important structural and functional constituents of cells in biological systems.The main focus is on the state of the art in the various areas covered, with an indication of the current developments taking place and the problems and challenges that remain to be addressed.Lipids contribute to many desirable qualities to foods, including attributes of texture, structure, mouthfeel, flavour, and colour. Generally, the quality of food is closely related to the quality of their lipids. Very often, the degradability and alteration of lipids are the main causes of the loss of quality of food. This is why several researchers have investigated the lipid fraction of food not only to provide new knowledge about their composition but also to assess whether it was possible inhibiting or slowing down alteration processes or modifying the native composition by fortifying foods with some lipid classes with health properties. They are a major source of energy and provide essential lipid nutrients. Nevertheless, over-consumption of certain lipid components can be detrimental to our health, e.g. cholesterol and saturated fats. In many foods the lipid component plays a major role in determining the overall physical characteristics, such as flavor, texture, mouthfeel and appearance. For this reason, it is difficult to develop low-fat alternatives of many foods, because once the fat is removed some of the most important physical characteristics are lost. Finally, many fats are prone to lipid oxidation, which leads to the formation of off-flavors and potentially harmful products.