Unfortunately I can't access the full article, but this abstract briefly describes a study to test whether a health promotion magazine would make people provided the magazine more health conscious.
Can I get a "duh" from the audience?
There's good news here. Knowledge in the pre-test was already high, and it improved. What's missing, of course, is a control group, but I think we can safely say that when the boss says here's a magazine we're gonna put in front of you, employees will learn something from it.
Eighty-seven percent said they read the mag and "showed enthusiasm for continued delivery." Yup, but ask 'em if they'd actually pay for it and watch 87 become 7.