Objective  To explore the impact of the family dinner index (FDI) on subjective well-being among the elderly and analyze the chain mediating role of intergenerational solidarity and loneliness.

Methods  A cross-sectional survey was conducted from September to December 2024 via multistage sampling, involving 1 165 elderly residents (≥60 years) in District D of Tianjin city. Data were collected by the Family Dinner Index Scale, Intergenerational Solidarity Scale, Loneliness Scale, and Subjective Well-being Scale. Structural equation modeling and the Bootstrap method (5 000 resamples) were employed to test the mediating role.

Results  The scores of the Family Dinner Index, Intergenerational Solidarity, Loneliness, and Subjective Well-being Scales were (32.45±8.72), (68.34±15.23), (18.56±5.89), and (36.78±6.95), respectively. The structural equation model demonstrated a high degree of fitting (χ²/df = 1.98, CFI = 0.97, RMSEA = 0.036). Path analysis revealed that the FDI directly and positively predicted subjective well-being (β = 0.20, P < 0.001) and intergenerational solidarity (β = 0.39, P < 0.001), while directly and negatively predicting loneliness (β = –0.18, P < 0.001). Intergenerational solidarity negatively predicted loneliness (β = –0.50, P < 0.001) and positively predicted subjective well-being (β = 0.25, P < 0.001). Loneliness directly and negatively predicted subjective well-being (β = –0.43, P < 0.001). The FDI influenced subjective well-being through the chain path from intergenerational solidarity to loneliness.

Conclusions  Family dinners significantly enhance subjective well-being of the elderly by strengthening intergenerational solidarity and alleviating loneliness. The findings provide a scientific basis for formulating family-oriented policies in response to aging.