The Eight

Nothing here is fast.Everything here is sourced.

Eight markers. Every one opens the study it came from.

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One from each domain— the headline number in its group, not the strongest evidence
Sleep DurationLifestyle
19%higher
4 hoursRISK OF DYING

sleeping 4 hours a night instead of 7 (Yin 2017)

Grade B
32%higher
10 hoursRISK OF DYING

sleeping 10 hours a night instead of 7 (Yin 2017)

Blood PressureCardiometabolic
2xhigher
HEART & STROKE DEATH

for every 20 points higher on the top blood-pressure number, and 10 on the bottom — down to 115/75 (Lewington)

Grade B
Daily StepsPhysical Capacity
47%lower
RISK OF DYING

walking 7,000 steps a day instead of 2,000 (Ding 2025, 14 studies)

Grade B
See all eight
What the composite doesn't do

An index, not a risk estimate. 50 is a typical person on all eight. The scale goes to 100; that is a cap, not a test score. This is a weighted average of single-marker associations from published studies. The weights are a judgment call, and the combined number has never been validated against health outcomes — no study has measured all 8 markers on the same people. Use it to decide what to work on, not to estimate your risk.

Ready when you are

See your number in two minutes.

One realistic change moves the composite by a few points at most. The roadmap after your score leads with what adds up, not what sounds biggest.

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