How to live longer
Not a listicle. Every factor below is ranked by how far the best answer beats the worst one in all-cause mortality, using the same hazard ratios the calculator runs on. The top three are worth more than everything underneath them combined.
The honest summary: do not smoke, keep your weight in the flat part of the curve, move most days, sleep seven to eight hours, drink less than you currently do, and keep two or three real friendships alive. That is essentially the whole of the evidence. Everything else is rounding.
- 01
Smoking
3.2× spreadQuitting is the single largest lever on this page. Ten years smoke-free returns most of the excess risk; quitting before 40 avoids about 90% of it.
Best answer
Never smoked HR 0.88
Worst answer
Over a pack a day HR 2.85
Jha et al., NEJM 2013; Doll et al., BMJ 2004
How much does smoking change your life expectancy? → - 2.8× spread
Mortality risk is flattest between BMI 20 and 25. Moving one band toward that range is worth more than any supplement on the market.
Best answer
Lean HR 0.96
Worst answer
Severely obese HR 2.70
Global BMI Mortality Collaboration, Lancet 2016
How much does body weight change your life expectancy? → - 03
Alcohol
1.6× spreadRisk climbs steadily above about 7 drinks a week. There is no dose that lengthens life, but the difference between 20 drinks and 7 is measured in years.
Best answer
1–7 a week HR 0.99
Worst answer
36+ a week HR 1.58
Wood et al., Lancet 2018 (599,912 drinkers)
How much does alcohol change your life expectancy? → - 1.4× spread
Social isolation carries mortality risk in the same league as smoking. Two or three real friendships, actually maintained, is a measurable intervention.
Best answer
Close, reliable people HR 0.90
Worst answer
Genuinely lonely HR 1.28
Holt-Lunstad et al., PLOS Medicine 2010 (148 studies)
How much does connection change your life expectancy? → - 05
Diet
1.4× spreadLegumes, whole grains and nuts up; processed and red meat down. Modelling says a sustained shift is worth years, and most of the gain comes from the first few swaps.
Best answer
Genuinely excellent HR 0.89
Worst answer
Mostly fast food HR 1.24
Fadnes et al., PLOS Medicine 2022; Schwingshackl et al. 2017
How much does diet change your life expectancy? → - 06
Movement
1.4× spreadThe steepest part of the curve is the first 75 minutes a week. Going from nothing to a brisk 20-minute walk most days buys back more than doubling an already-good routine.
Best answer
300+ min a week HR 0.91
Worst answer
Basically none HR 1.26
Arem et al., JAMA Internal Medicine 2015
How much does movement change your life expectancy? → - 07
Stress
1.4× spreadChronic stress is not a mood, it is a cardiovascular exposure. Anything that reliably drops your baseline — therapy, boundaries, a different job — is a longevity intervention.
Best answer
Rarely stressed HR 0.95
Worst answer
Running on empty HR 1.30
Kivimäki & Steptoe, Nature Reviews Cardiology 2018
How much does stress change your life expectancy? → - 08
Sleep
1.3× spreadSeven to eight hours is the floor of the risk curve, and both ends are dangerous. Fixing sleep is usually the cheapest year on this list.
Best answer
7–8 hours HR 0.97
Worst answer
9+ hours HR 1.28
Cappuccio et al., Sleep 2010 (meta-analysis, 1.38M people)
How much does sleep change your life expectancy? →
The two things this list cannot tell you
Which one matters most for you. A hazard ratio is a population average. If you already do not smoke, the smoking row is worth nothing to you and the sleep row might be worth years. That ordering is personal, and it is what the calculator works out.
How much is causation. These come from observational cohorts. Smoking is about as close to proven causation as epidemiology gets. Diet and stress are real but softer — people who eat well differ from people who do not in a hundred ways that no adjustment fully removes.
Which of these is costing you the most?
The calculator ranks them for your answers and puts a number of years on each.