Guides to the science behind your score.
Each factor in the Helixspan model draws on a body of population research. These guides go deeper than the homepage summaries — the mechanisms, the caveats, and what the evidence actually supports.
What is healthspan, and why isn't it the same as lifespan?
The concept behind the whole model: healthy life expectancy, compression of morbidity, and why the last decade of life is where most chronic illness concentrates.
Read the guide Factor · SmokingSmoking and healthspan: what quitting actually recovers
Why smoking is the single largest modifiable factor in the model, and how much of the lost healthspan comes back after quitting — and how fast.
Read the guide Factor · Body weightThe U-shaped curve: BMI and healthy life expectancy
Why both underweight and severe obesity carry a healthspan cost, and why the "ideal" BMI range is wider and more forgiving than most people assume.
Read the guide Factor · ExerciseThe minimum effective dose of exercise for healthspan
Why the biggest gains come from going from zero to a little, why 300 minutes a week is a reasonable ceiling, and what "moderate intensity" means in practice.
Read the guide Factor · SleepWhy sleep has a U-shaped mortality curve, not a "more is better" one
The evidence behind the 7–8 hour window, why long sleep is a risk marker too, and what consistently disrupted sleep does over decades.
Read the guide Factors · Diet, alcohol, stressDiet quality, alcohol thresholds, and chronic stress
Three smaller but meaningful modifiers: what a Mediterranean-style diet score is actually measuring, where the alcohol risk curve bends, and how chronic stress compounds over decades.
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