If you're going to read one thing about the new Dietary Guidelines, a.k.a. the Food Pyramid, a.k.a. the USDA My Plate, then make it be Georgia Ede's article: http://www.diagnosisdiet.com/2015-dietary-guidelines-critique
It's long, but that is because it is packed with facts. Be sure to read the part toward the end where she looks at all 19 of the studies that were used to implicate red meat in depression, and discovers that those studies actually exonerate red meat as being a factor in depression, which is the opposite of what the Dietary Guidelines claim.