Field
Behaviour
What is actually done — movement, sleep, food, company, substances.
- The boring basicssettledThe short list that accounts for most of the modifiable risk. Nothing on it is interesting.
- Daily step count and mortalitygoodMore steps track with lower mortality. The round-number target is arbitrary; the gains start far below it.
- Exercise and agingsettledThe intervention with the widest evidence base in this reference, by a distance.
- Meal timing and circadian rhythm: what the trials measured on a clockmixedThe early eating window moves glucose and the clock. It does not move the microbiome, and the effect sizes are small.
- Nuts and mortalitygoodA handful of nuts a day tracks with living longer. The nut probably gets too much credit.
- Protein in later lifegoodEFSA's 0.83 g/kg is a floor for adults generally; older adults are usually advised higher.
- Purpose in life and mortality: what the cohorts actually showmixedPurpose tracks mortality in every cohort that has measured it. Nobody has assigned it, so nobody knows whether it does anything.
- Sedentary timemixedAn exposure distinct from inactivity. Real, and less catastrophic than the headlines.
- Sleep and aginggoodSeven to nine hours. Sleep changes shape with age; the requirement does not fall much.
- Sleep fragmentation vs sleep duration: which one correlates with whatmixedFragmentation tracks with frailty, death and midlife cognition where duration does not. Nobody has run the experiment that would settle it.
- Smoking and alcoholsettledStopping smoking is the single largest return available. Alcohol's safe level keeps shrinking.
- Social connection and isolationmixedA well-replicated association with an unusually stubborn reverse-causation problem.
- Social connection and mortality: what 90 cohorts and 2.2 million people showmixedThe association is the largest in the social determinants literature. The causal claim has never been tested in an experiment, and the weakest component — living alone — is the one everybody quotes.
- Strength training after sixtysettledTwo sessions a week, progressive load. Nothing else does what this does.