Conventional edible oils, such as sunflower, safflower, soya bean, rapeseed (canola) oils, were modified to obtain high-oleic, low-linoleic or even low-linolenic oils. The aim was to develop salad, cooking and frying oils, that are very stable against lipid peroxidation. They are also suitable for margarine blends, as additives to cheeses and sausages, or even as feed components. Oils containing higher amounts of medium-chain length or long-chain polyunsaturated fish oil fatty acids are suitable as special dietetic oils or as nutraceuticals. High-stearic oils are designed as trans-fatty acid-free substitutes for hydrogenated oils. New tailor-made (designer) oils are thus a new series of vegetable oils suitable for edible purposes, where conventional oils are not suitable.