On the federal level, economics are surely the major reason behind exhaustive research into the diets and just about every aspect of American health habits by the National Institutes of Health, the Institute of Medicine, and the Centers for Disease Control (CDC). But even these studies, which often include tens of thousands of subjects, are not always watertight in their conclusions.

This point was made during the February 21st edition of the PBS Newshour. The program included a segment in which the host, Ray Suarez, and his guests analyzed recently released CDC data about an apparent reduction in caloric intake among US children and adults.

Despite the decline in calories, obesity rates among children remain relatively unchanged. So Suarez opened the discussion with an appropriate question:

“I know there are caveats and things to be further explained, but just the gross statistics, adults consuming fewer calories from fast food, children consuming fewer calories overall, that’s good news, isn’t it?”

Michael Moss, the Pulitzer-prize winning journalist and author of a new book, Salt, Sugar, Fat: How the Food Giants Hooked Us (adapted in a fascinating February 24th New York Times Magazine cover story) wasn’t so sure. And neither was William Dietz, the former director of the CDC’s Division of Nutrition, Physical Activity, and Obesity. Deitz argued that the CDC data suggest economic factors and declining rates of physical activity as more plausible explanations for the results, and said that a much more focused effort must be made to change child obesity rates.

They all agreed that the findings should be taken with a grain of salt. (Sorry!)

Sibyl Shalo Wilmont is a healthcare journalist and emergency department nurse with insider experience in the pharmaceutical industry, academic medicine, and patient advocacy. She is a graduate student in Hunter College's dual-degree Master's in Community/Public Health Nursing/Master's in Public Health program. Follow her on Twitter @nursesibyl.