Evaluating the efficacy of a theory-based nutrition education intervention for pregnant and pre-pregnant women in Beijing, China: a quasi-experimental pilot study

Maternal nutrition plays a critical role in promoting positive pregnancy outcomes. However, many pregnant and pre-pregnant women in China do not meet dietary recommendations. Theory-driven interventions are needed to encourage healthier dietary behaviors. This pre-post single-arm pilot study evaluated the efficacy of a theory-based online nutrition education intervention grounded in the Theory of Planned Behavior (TPB). Seventy-one pregnant and pre-pregnant women were recruited from a private hospital in Beijing, of whom 40 completed both baseline and post-intervention assessments. The six-week intervention, delivered via WeChat, included livestream sessions, text-based materials, and group discussions targeting TPB constructs and promoting behaviors aligned with Chinese dietary guidelines. Changes in psychosocial determinants, dietary behaviors, and weight status were assessed using validated questionnaires and self-reported data. Wilcoxon signed-rank tests were conducted to evaluate pre-post changes, with the Benjamini-Hochberg procedure applied to control for multiple comparisons. Significant improvements were observed in six psychosocial determinants: attitudes ( p = 0.018), perceived norms ( p = 0.002), perceived behavioral control ( p = 0.008), self-depictions ( p = 0.028), behavioral intentions ( p = 0.035), and skills and abilities ( p = 0.027). Participants significantly increased their intake of soya and soya products ( p = 0.008), milk and dairy products ( p = 0.003), and fish and seafood ( p = 0.010). They also reported more frequent nutrition label reading ( p = 0.007). No significant changes were observed in cooking behaviors, intake of ultra-processed foods, or weight status. The TPB-based online nutrition education intervention effectively improved psychosocial determinants and selected dietary behaviors among pregnant and pre-pregnant women in Beijing. Future interventions should address environmental barriers, promote reductions in unhealthy food intake, and incorporate physical activity components to enhance health outcomes. Chinese Clinical Trial Registry ChiCTR2300071126, registered on May 5, 2023.