For the podcast listener: Thought this was a particularly good one. Nice discussion of different types of fats: good (monounsaturated and polyunsaturated, particularly from plants) and bad (saturated, trans-, from partially hydrogenated vegetable oil)
Restrictions on Trans Fats - SciFri Podcast - 2006110324
Good Fats, Bad Fats, and Trans Fats
A sizzling steak with a pat of butter on top. Tuna, trout, or herring. A pile of crispy french fries. A flaky biscuit or delicate pie crust. Sure, all have some fat in them - but which fats are good, which are bad, and which are somewhere in between?...
Trans fatty acids (commonly termed trans fats) are a type of unsaturated fat (and may be monounsaturated or polyunsaturated)...
Chemically, trans fats are made of the same building blocks as non-trans fats, but have a different shape. In trans fat molecules, the double bonds between carbon atoms (characteristic of all unsaturated fats) are in the trans rather than the cis configuration, resulting in a straighter, rather than a kinked shape. As a result, trans fats are less fluid and have a higher melting point than the equivalent cis fats.