Several low-fat foods have been available for a long time on the French market. However, the process of eliminating fat leads to a decrease in the palatability of the end-product. In order to partially correct this problem, fat replacers and substitutes have been developed by the food industry : fibers, gums, starches, protein products, emulsifiers, etc. These products are considered safe. A new generation of fat substitutes are synthetic oils and lipids which have recently been approved for industry use. The main question regarding these fat substitutes is that of their ability to help the consumer reduce fat and energy intakes, and to affect long-term nutritional status and body weight control. laboratory studies carried out over days or weeks yield promising results, but they have to be completed and confirmed by longer term investigation under field conditions. If it is demonstrated that the use of fat substitutes can induce a significant and prolonged reduction in fat intake, then the fat-soluble vitamin status should be verified in consumers, especially in sensitive populations such as adolescents and elderly subjects.