30g fiber/day
Most adults eat half what they need. Strong dose-response with all-cause mortality.
Why
Fiber feeds gut microbiota, slows glucose absorption, supports cardiovascular health, and predicts mortality independent of other dietary factors. Most adults consume 12–15g/day; the target for cardiovascular benefit is 25–30g+. Whole foods (legumes, vegetables, oats, berries) are better sources than supplements.
Slot in your day
How to do it
How
Add a serving of beans/lentils most days. Berries with breakfast. Vegetables at lunch and dinner. Tracked once for a week, the gap to 30g becomes obvious.
Markers this may influence
Evidence
Reynolds 2019 Lancet meta-analysis (185 prospective studies and 58 RCTs, commissioned by WHO): highest vs lowest fibre consumers had 15–30% lower all-cause and cardiovascular mortality, with the steepest risk reduction at 25–29 g/day intake. Dose-response suggests further benefit above 30 g/day. Most adults consume 12–15 g.