Transport Motorization and Household Food Waste in Rural China: Direct-Weighing Evidence of a Nonlinear Association

Avoidable household food waste can arise at multiple stages of household food management, including storage, preparation, cooking, consumption, and post-cooking storage. It may also be associated with upstream food access and purchasing conditions. Using a purpose-designed 2017 survey of 204 rural households in Shandong, China, this study combines three-day household tracking with direct weighing of avoidable edible food waste. A food-purchase transport motorization index (TMI) is constructed from food-category-specific transport modes weighted by household consumption shares. Its association with observed food waste is examined using Tobit models, interval shape tests, and sensitivity analyses. TMI exhibits a nonlinear statistical association with total food waste: fitted waste increases at lower motorization levels and tends to decrease at higher levels, although formal interval tests do not confirm an inverted-U relationship for total waste. The nonlinear pattern is clearest for storage waste, whereas plate waste shows a positive linear association. TMI is significantly associated with waste occurrence, but its association with the amount wasted among households with positive waste is not statistically significant. Purchase frequency strengthens the association between TMI and waste occurrence, whereas dietary diversity shows no comparable moderating role. Associations are more pronounced for non-perishable and plant-based foods than for perishable or animal-based foods. These findings provide short-term micro-level evidence from a rural transport-transition setting.