Gaining Weight and Losing Ground

A scene from Chris Teerink’s documentary "Sol LeWitt," showing an installation by the Sol LeWitt.

Laurie David talks about her new documentary “Fed Up,” which explores what’s driving America’s obesity epidemic and why cutting the fat from our diets hasn’t led to widespread weight loss. Director Leigh Silverman and star Sutton Foster tell us about the Broadway musical “Violet.” Filmmaker Chris Teerink discusses the conceptual artist Sol LeWitt. This week’s Please Explain looks at polio and why a disease that was once on the verge of eradication is making a comeback.