Work group III: Methodologic issues in research on the food and physical activity environments: addressing data complexity.

Progress in transdisciplinary research addressing the health effects of the food and physical activity environments appears hampered by several methodologic obstacles, including: (1) the absence of clear, testable conceptual models; (2) slow adoption of practicable, rigorous research designs; (3) improper use of analytic techniques; and (4) concerns about ubiquitous measurement error. The consequence of such obstacles is that data collected as part of the typical study are more complex than need be. We offer diagnoses and recommendations from an NIH-sponsored meeting that addressed core issues in food- and physical activity-environment research. Recommendations include improved conceptual models and more elaborate theories, experimental thinking and increased attention to causal effect estimation, adoption of cross-validation techniques, use of existing measurement-error models, and increased support for methodologic research.