Eating 5 servings (about 400 g) of fruits and vegetables daily

Cost: It costs only a few to a dozen yuan per day. You also need to spend some time washing and chopping them. The real challenge is buying and eating the required amount every single day.
In plain terms: Consuming an extra 200 g of fruits and vegetables each day lowers the risk of death by roughly 10% during the same period. People who eat 5 servings daily have a mortality risk that is about 13% lower than those eating just 2 servings. Eating more than that does not bring any further reduction in risk.
Benefit: When pooling data from multiple longitudinal studies (without subgroup analysis), an additional 200 g of fruits and vegetables per day is linked to a 10% drop in death risk (RR 0.90). This protective effect persists up to 800 g per day. A combined analysis of two large US longitudinal studies and 26 other studies shows that people eating 5 servings daily have a mortality risk that is about 13% lower than those eating only 2 servings (HR 0.87). The optimal mix is 2 servings of fruit and 3 servings of vegetables; any extra amount beyond that does not lower the risk further.
Evidence grade: A
Sources:Aune D 等 (2017). Fruit and vegetable intake and the risk of cardiovascular disease, total cancer and all-cause mortality: a systematic review and dose-response meta-analysis of prospective studies. International Journal of Epidemiology. https://doi.org/10.1093/ije/dyw319；Wang DD 等 (2021). Fruit and Vegetable Intake and Mortality: Results From 2 Prospective Cohort Studies of US Men and Women and a Meta-Analysis of 26 Cohort Studies. Circulation. https://doi.org/10.1161/CIRCULATIONAHA.120.048996
Notes: Eating 5 servings is sufficient; there is no need to reach 10 servings, as both studies agree on this point. Keep in mind that these studies are purely observational, so confounding factors are inevitable: people who eat more vegetables and fruit tend to have higher incomes, better education, and more physical activity than others. Therefore, the reported 10% risk reduction represents the upper limit of the true effect.