Tabitha M. Powledge examines the multiple controversies over new federal dietary guidelines and suggests that one of the nation's biggest nutrition issues may be devilishly difficult to solve: "A consistent complaint about nutrition science is that one of its most important research tools, what people tell investigators about what they eat, is inherently untrustworthy. That’s because self-reports of any kind are inherently untrustworthy. People forget. And people lie."
January 23, 2016
