In the TRANSFAIR study, foods contributing to 95% of total fat intake were collected in 14 European countries. In addition to edible fats, dairy, meat, and bakery products some specific food items with relatively high amounts of trans fatty acids were found. French fried potatoes, both those from fast-food restaurants and those from the supermarkets (including potato chips), contained mostly between 12 and 35% trans fatty acid, but some products fried in animal fat or vegetable oil contained lower proportions between 0.5 and 7% total fatty acids. Deep-fried croquettes were also rich in trans fatty acids. Microwave popcorn samples contained 27-34% trans fatty acids. Ready-made popcorn was low in trans fatty acids but generally contained even more saturated fatty acids. Dry soup and sauce mixes and cubes and high-fat, frosted breakfast cereals were other examples of foods that often contained ΟΎ10% trans fatty acids. It is concluded that any deep-fried product such as French fried potatoes may contain high proportions of isomeric trans fatty acids. Processed foods with a long shelf life such as dry soup powders and cubes, savory snacks, and popcorn often contained relatively high proportions of trans fatty acids, although the contributions of these products to total fat intake are probably small. The foods and snacks with a high proportion of trans fatty acids usually contained less saturated fatty acids and more cis-unsaturated fatty acids than respective foods prepared with low-trans saturated vegetable fats or animal fats.