Understanding the marketing of BMS in China through pregnant women and new mothers' diary.

Background: Despite strong evidence supporting breastfeeding's benefits for maternal and child health, breastfeeding rates (e.g. any breastfeeding, exclusive breastfeeding for the first six months etc.) in China are still suboptimal. The pervasive marketing of breast-milk substitutes (BMS) plays a significant role. Yet research on BMS marketing-especially in China-is scarce, and a clear characterization of the channels and underlying themes through which pregnant women and new mothers encounter such advertising is critical for informing effective regulation of BMS promotions, advancing breastfeeding practices and ultimately improving maternal and child health.

Methods: A marketing diary approach was employed in a one-week pilot study involving 20 participants in Beijing and Jinan, China. Each participant was required to document all BMS marketing-related messages encountered-capturing screenshots or photos and annotating channel and thematic content. Quantitative exposure proportions by channel were calculated, and qualitative data underwent thematic content analysis by two independent coders. This study aimed to preliminarily map the online marketing ecology of BMS and to compare these findings against existing regulatory frameworks, thereby informing actionable recommendations to strengthen monitoring of compliance of BMS marketing.

Results: A total of 234 BMS marketing records were documented, 90.2% of which occurred via digital platforms. Among online channels, social media (45.3%), e-commerce websites (15.4%), video streaming platforms (15.0%) and general web browsing (14.5%) predominated; offline channels accounted for the remaining 9.8%. Four principal promotional strategies were identified-competitive promotions, nutritional claims, corporate identity building and word-of-mouth endorsements. Eight thematic categories emerged, led by nutrition claims, sales promotions and infant health benefits. Several participants critically appraised ambiguous or scientifically unsubstantiated assertions.

Conclusions: Chinese pregnant women and mothers of infants aged 0-18 months encounter frequent, multifaceted BMS marketing (activities, or strategies, or tactics) predominantly through digital channels. China's current regulatory framework governs food labelling but affords limited monitoring of BMS advertising across all channels-particularly digital platforms-underscoring the need for comprehensive regulation that explicitly includes online marketing tactics. A multisectoral strategy-combining policy reform, targeted health education and rigorous enforcement of the International Code of Marketing of Breast-milk Substitutes (the International Code)-is required to protect and promote breastfeeding.