This research didn't seem to investigate trans fats, but rather the effect of unprocessed food that's high in fiber vs processed food that's low in fiber.

The last book I read that discussed fats is a bit out of date (The Story of the Human Body: Evolution, Health, and Disease by Daniel Lieberman), but it has an interesting explanation of the differences between saturated, unsaturated, and trans fats. Then the author reveals the plot twist that well... maybe the different fats don't actually make that much difference once they're in the body and that current research is still unclear.