(http://www.pbs.org/wnet/need-to-know/files/2010/10/karronculture-badge1.gif) This week on our Karr on Culture podcast: Former Secretary of Agriculture Dan Glickman discussed the tug-of-war between good nutrition and good farm policy. On the most recent Need to Know, we followed up (http://www.pbs.org/wnet/need-to-know/health/video-mixed-signals-why-is-the-usda-promoting-nutrition-and-pushing-cheese/5296/) on a New York Times report (http://www.nytimes.com/2010/11/07/us/07fat.html) on agricultural promotion programs whose messages sometimes undercut efforts by the USDA (http://www.mypyramid.gov/)-- and First Lady Michelle Obama (http://www.letsmove.gov/) -- to combat obesity and encourage Americans to eat healthy foods. Our reporting uncovered 17 such programs, promoting commodities from milk (http://www.gotmilk.com/) to peanuts (http://www.nationalpeanutboard.org/), several of which have partnered with fast-food chains to promote menu items (http://www.quiznos.com/signature6.html) that nutritionists say are unhealthy. Dan Glickman says there's nothing surprising in the tension between those messages, given the USDA's multiple mandates. He says information is Americans' best weapon against the advertising of unhealthy foods.