Eat 5 servings (about 400 g) of fruit and vegetables a day

Moderate value
Evidence A
Buys life
Costs a little
Takes some hours
Some willpower

In plain words

People who eat 200 g more vegetables and fruit a day have about a 10% lower chance of dying over the same period. People who eat 5 servings a day are about 13% lower than people who eat only 2. Eating more than that doesn't lower it further.

Cost: A few to a dozen or so CNY a day. You spend some time each day washing and cutting. The hard part is buying them every day and eating enough every day.
What you get: Pooling several follow-up studies (observational, not assigning groups): each extra 200 g of fruit and vegetables a day was linked to about 10% lower risk of death (RR 0.90). This benefit continues up to 800 g a day. Two large U.S. follow-up studies plus a pooled analysis of 26 studies: people who ate 5 servings a day had about 13% lower risk of death than people who ate only 2 (HR 0.87). The best mix is 2 servings of fruit plus 3 of vegetables; more than that does not lower it further.
Notes: 5 servings is enough; you don't need to reach 10, and the two studies agree on this. Keep in mind that these studies only followed people, and the confounding is obvious: people who eat a lot of vegetables differ from others in income, education and exercise. So “about 10% lower risk” is already an upper limit.
Evidence grade: A : Specific numbers from meta-analyses, large cohorts or randomized trials; for law and policy, the statute or official text.
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

Mentioned in

Don't count on eating breakfast or 16:8 intermittent fasting to control your weight; choose meal times you can keep up long term

Translated from the Chinese original. Original book, section 2, tip 27. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer