Traffic Light Diets for Childhood Obesity: Disambiguation of Terms and Critical Review of Application, Food Categorization, and Strength of Evidence.

Traffic light labeling (TLL) of foods is a strategy often included in multicomponent behavioral interventions (MBIs) for childhood obesity. Traffic light labels categorize foods as "green" (no restrictions), "yellow" (moderation), and "red" (consume minimally). The body of research investigating the effects of TLL conflates the labeling itself with MBIs that include TLL as one component. For instance, the Academy of Nutrition and Dietetics' Evidence Analysis Library gave traffic light diets Grade I evidence for pediatric weight management. Yet, whether the term traffic light diet referenced TLL in isolation or as part of an MBI was ambiguous. Herein, we evaluate the evidence supporting TLL for childhood obesity as a stand-alone treatment and identify areas requiring further research. No articles from a PubMed search for TLL and weight-related outcomes tested TLL in isolation. One article was identified through reference lists that tested TLL mostly in isolation, which observed no significant differences between groups. TLL definitions and categorizations vary across studies and contexts, using average calories in categories of foods, energy density, or specific ingredients to determine labeling. Systematic reviews generally conclude TLL-based approaches affect food selection and consumption, but none studied obesity-related outcomes. We believe the evidence supports that: