Progress Evaluation for Transnational Restaurant Chains to Reformulate Products and Standardize Portions to Meet Healthy Dietary Guidelines and Reduce Obesity and Non-Communicable Disease Risks, 2000-2018: A Scoping and Systematic Review to Inform Policy.

Transnational restaurant chains sell food and beverage products in 75 to 139 countries worldwide linked to obesity and non-communicable diseases (NCDs). This study examined whether transnational restaurant chains reformulated products and standardized portions aligned with healthy dietary guidelines and criteria. Firstly, we describe the transnational restaurant industry structure and eating trends. Secondly, we summarize results from a scoping review of healthy dietary guidelines for restaurants. Thirdly, we describe a systematic review of five electronic databases (2000-2018) to identify studies on nutrient profile and portion size changes made by transnational restaurants over 18 years. We used Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, identified 179 records, and included 50 studies conducted in 30 countries across six regions. The scoping review found a few expert-recommended targets for restaurants to improve offerings, but no internationally accepted standard for portions or serving sizes. The systematic review results showed no standardized assessment methods or metrics to evaluate transnational chain restaurants' practices to improve menu offerings. There was wide variation within and across countries, regions, firms, and chains to reduce energy, saturated and trans fats, sodium, and standardized portions. These results may inform future research and encourage transnational chain restaurants to offer healthy product profiles and standardized portions to reduce obesity and NCD risks worldwide.