The trends of diversified diets in China have generated a growing number of nutritional health problems, and healthcare investment is bearing a large burden from the diets, hindering the economic progress of the country and its residents toward affluence. This study linked the evolution of the Chinese dietary structure to changes in health expenditures and predicts future dietary patterns and their impact on health costs over the next 30 years. We found that in the past 30 years, the Chinese dietary structure has shifted towards a nutritional surplus type, and the structure of health expenditures has also shown a trend of two increases and one decrease. The consumption of plant-based foods is significant correlated with lower health expenditures, and animal-based foods show a significant impact on increase of health expenditures. Among nutrients, fat is significant correlated with increased health expenditures, whereas calorie intake is significant correlated with lower health expenditures. By 2030, the Chinese dietary structure will still evolve to a high-protein and high-fatty type. This shift will result in a decrease in per capita healthcare expenditure by 41.66 yuan and increases in household, state, personal, and total healthcare expenditures by 76.83 yuan, 18.76 billion yuan, 95.28 billion yuan, and 17.67 billion yuan, respectively. These findings demonstrate that adjusting dietary structures will bring the dual benefits of improved national health status and a favorable cycle of health expenditures.