Sweet potato

What it does

Orange flesh is beta-carotene; purple varieties add anthocyanins.

• Beta-carotene, fibre

Where the number comes from

Sweet potato sits in the veg group of the Fadnes model, the only peer-reviewed model that converts eating into years of life. The lifetime gain for that group is spread across the days you actually eat it — a daily serving from age 20 to 80 — which gives +8 min per serving. The authors rate the evidence behind this group as low.

What it is made of

• Beta-carotene
• Fibre
• Anthocyanins (purple)

Which kind

• Orange sweet potato — beta-carotene leader
• Purple sweet potato — anthocyanins like berries
• White sweet potato — fibre but no pigment bonus

How to eat it

Baked with skin — the fibre is in the peel.

Minutes derived from Fadnes LT, Økland J-M, Haaland ØA, Johansson KA. Estimating impact of food choices on life expectancy: A modeling study. PLOS Medicine 19(2):e1003889, 2022. doi:10.1371/journal.pmed.1003889