Tastes so good but it's SO bad: The food industry's challenge: Find a way to replace trans fat in the foods we love to eat.

Byline: Jeremy Manier

Dec. 10--After a decade of dire research warnings, trans fat has become America's most loathed dietary demon, an ingredient so bad for you that Chicago lawmakers are considering following New York's lead and banning it altogether. The reason for the uproar is real enough--unlike any other fat used in cooking or frying, trans fat has the dual effect of increasing dangerous cholesterol and lowering levels of so-called "good" cholesterol. Replacing trans fat will be a costly project for many restaurants that rely on the oily, artery-clogging goo, mostly in frying and baking. Trans fat, which comes from the partially hydrogenated vegetable oil found in shortening and other ingredients, is an integral part of food items ranging from croissants to doughnuts to french fries.

Unhealthy it may be, but American consumers shell out billions of dollars for such cheap, fattening products. To meet that demand without using trans fat, farming operations will need to grow more of crops that currently are scarce, including new varieties of soybean and canola. Expensive blends of oils may be the only good alternative for some restaurants, and even then certain products may go stale more quickly. What may justify the hassle of transition…