BACKGROUND:
Maternal malnutrition remains a persistent public health challenge in South Africa, affecting both maternal and child health outcomes. Dietary practices during pregnancy and lactation are shaped by complex social dynamics that extend beyond individual choice. This study explored the influence of cultural and intergenerational power relations on maternal dietary practices in the context of clinical nutrition interventions.

METHODS:
We conducted a qualitative study in Capricorn district of Limpopo province (March–October 2025). Data comprised focus group discussions (n=22) and individual interviews (n=13) with 150 participants including pregnant women, grandmothers, fathers, community leaders, community health workers, mentor mothers, and healthcare providers. Data were analysed thematically. Interpretation drew on the Social Ecological Model and Bourdieu’s Theory of Practice.

RESULTS:
Four interconnected themes explained dietary behaviour. First, elder women, especially grandmothers and mothers-in-law, held decisive authority based on experiential knowledge framed as care, which often was accepted over healthcare advice. Second, pregnant women balanced competing guidance, using respectful deference in public and selective adherence in private. Third, poverty, distance, and poor infrastructure made clinical advice largely unattainable. Fourth, digital messaging and peer networks provided supplementary information that supported dialogue but did not displace elder authority. Interpretation: Maternal diet is shaped by intergenerational power dynamics and resource constraints rather than knowledge alone. Grandmothers enforce cultural dietary restrictions that conflict with clinical guidance, while pregnant women use public deference and private adaptation to navigate competing advice. Nutrition interventions must engage elders as partners and employ culturally respectful harm-reduction strategies.