The Louisville Metro Board of Health is expected to recommend a trans fat ban to the Metro Council.The substance is added to some foods as a preservative, but is also linked to heart disease. The board spent months studying trans fat and will review its findings at a meeting Wednesday morning. Its report will go to health department director Adewale Troutman, who will present it to the Metro Council. He's expected to ask the council to pass legislation banning trans fat.Council Health and Human Needs Committee chair Vicki Welch says Troutman would have to report compelling arguments for a ban before she votes for it."Restaurants in our community have already dropped trans fats," she says. "We've done a lot of education initiatives out in the community through the health department and on Dr. Troutman's watch."The committee will either take up the issue Wednesday, or two weeks later, depending on how long Dr. Troutman takes to prepare his report.The council could also encourage all restaurants to stop using trans fats or call for a public education campaign.