Reducing Salt Intake in China with "Action on Salt China" (ASC): Protocol for Campaigns and Randomized Controlled Trials

Abstract

Background: Salt intake in China is over twice the maximum recommendation of the World Health Organization. Unlike most developed countries where salt intake is mainly derived from prepackaged foods, around 80% of the salt consumed in China is added during cooking. Objective: Action on Salt China (ASC), initiated in 2017, aims to develop, implement, and evaluate a comprehensive and tailored salt reduction program for national scaling-up. Methods: ASC consists of six programs working in synergy to increase salt awareness and to reduce the amount of salt used during cooking at home and in restaurants, as well as in processed foods. Since September 2018, two health campaigns on health education and processed foods have respectively started, in parallel with four open-label cluster randomized controlled trials (RCTs) in six provinces across China: (1) app-based intervention study (AIS), in which a mobile app is used to achieve and sustain salt reduction in school children and their families; (2) home cook-based intervention study (HIS), in which family cooks receive support in using less salt; (3) restaurant-based intervention study (RIS) targeting restaurant consumers, cooks, and managers; and (4) comprehensive intervention study (CIS), which is a real-world implementation and evaluation of all available interventions in the three other RCTs. To explore the barriers, facilitators, and effectiveness of delivering a comprehensive salt reduction intervention, these RCTs will last for 1 year (stage 1), followed by nationwide implementation (stage 2). In AIS, HIS, and CIS, the primary outcome of salt reduction will be evaluated by 24-hour urinary sodium excretion in 6030 participants, including 5436 adults and 594 school children around 8-9 years old. In RIS, the salt content of meals will be measured by laboratory food analysis of the 5 best-selling dishes from 192 restaurants. Secondary outcomes will include process evaluation; changes in knowledge, attitude, and practice on salt intake; and economic evaluation. Results: All RCTs have been approved by Queen Mary Research Ethics Committee and the Institutional Review Boards of leading institutes in China. The research started in June 2017 and is expected to be completed around March 2021. The baseline investigations of the four RCTs were completed in May 2019. Conclusions: The ASC project is progressing smoothly. The intervention packages and tailored components will be promoted for salt reduction in China, and could be adopted by other countries.