To investigate the factors associated with intergenerational transmission of weight status in low-income families in China and to provide evidence for policies aimed at interrupting the vertical inequality in health.

Utilizing data from the 2022 China Family Panel Studies (CFPS), we employed Multinomial Logistic Regression Model(MLOGIT) models to analyze the associations.

Maternal weight status showed significant effects on offspring weight. Compared to mothers with normal weight, underweight mothers were associated with a 56.7% higher risk of offspring being underweight (OR=1.567, P<0.05) and a 41.9% lower risk of offspring obesity (OR=0.581, P<0.05). Obese mothers were associated with a 55.5% increased risk of offspring obesity (OR=1.555, P<0.05). Paternal weight status had a limited influence on offspring weight outcomes, with no significant association observed between paternal obesity and offspring obesity. Male offspring and children of younger age exhibited a higher likelihood of being overweight or obese. Higher educational attainment of both parents was significantly associated with a reduced risk of offspring overweight or obesity. Furthermore, maternal rural residency was linked to a complex pattern, potentially associated with a decreased risk of offspring underweight yet an increased risk of obesity.

In low-income families, parental weight status is strongly correlated with offspring weight status. Mothers serve as more comprehensive and direct influencers on offspring health, whereas the influence of fathers is relatively limited. Offspring characteristics and household economic factors are also important determinants of offspring health. Therefore, breaking the intergenerational transmission of weight disadvantages in low-income families requires differentiated strategies.