A different question than “How long will I live?”

When people think about health, they often focus on methods, routines, or numbers. More exercise. Better nutrition. Better sleep metrics. Less often, a more fundamental question is asked: How do I want to feel in ten, twenty, or thirty years? This question is less technical, but often more honest. In everyday life, people do not experience health as a metric. They experience it as energy or fatigue, clarity or mental fog, mobility or limitation. Healthy aging is therefore rarely understood as living as long as possible, but rather as staying functional for as long as possible.

Living longer and living well are not the same thing

Modern medicine has achieved one major success: people live longer. What it has addressed far less is the quality of those additional years. In many Western countries, average life expectancy now exceeds 80 years. The number of years people spend without significant functional limitations is considerably lower. The gap between the two has barely narrowed over recent decades. This is why research increasingly distinguishes between lifespan and healthspan. Lifespan describes how long a person lives. Healthspan describes how long a person remains physically, mentally, and emotionally functional. A longer life may result from good functional health. It is not its primary objective.

Health is experienced as a capability, not an ideal state

Health is often viewed in binary terms: healthy or sick. In reality, it exists on a continuum.

Many relevant changes develop gradually:

• persistent fatigue
• reduced resilience
• slower recovery
• diminished mental clarity

These changes are often not yet disease. But they indicate that the body’s ability to cope with stress is declining.

Healthy aging, in this sense, does not mean avoiding illness. It means maintaining functional capabilities:

• physical
• metabolic
• mental
• emotional

These capabilities determine whether stress leads to adaptation or to exhaustion.

Why tasks rarely motivate, but states do

Research on behavior change consistently shows a similar pattern: people do not stay engaged because of tasks, but because of outcomes they can relate to emotionally. “Exercise more” or “sleep better” are abstract instructions. “Feeling energetic” or “staying mentally clear in daily life” are concrete desired states. When health is reduced to tasks, motivation often fades. When health is understood as a prerequisite for a good life, the perspective shifts. Actions become means to an end, not ends in themselves.

Why prevention often starts too late

One core challenge of preventive health is invisibility. Disease is noticeable. Health is quiet. Functional changes are therefore often normalized for years — as a consequence of stress, age, or life circumstances — until clear medical findings appear. From a preventive perspective, that is late.From a human perspective, it is understandable. Healthy aging therefore requires less discipline than awareness: the ability to notice changes before they become fixed.

What can and cannot be promised

No one can guarantee how long a person will live. No one can promise that all health risks can be avoided. What is realistic is a structured approach to health:

• orientation instead of actionism
• regular reflection instead of isolated checks
• medical interpretation instead of self-diagnosis
• feedback instead of blind routines

Such an approach does not promise outcomes. It creates better conditions for functional stability over time.

Summary

Healthy aging does not mean adding as many years as possible to life. It means allowing as many years as possible to be lived with function. People who think about health in terms of desired states rather than tasks often make more sustainable decisions — not because they do more, but because they prioritize more clearly. If a longer life results from this, it is a positive side effect. The underlying goal remains: to feel well over many years.

Scientific background and context

• World Health Organization (2015): World Report on Ageing and Health
• Global Burden of Disease Study 2019, The Lancet
• Fries JF (1980): Aging, Natural Death, and the Compression of Morbidity, NEJM
• BCG Global Study on Longevity (2025): The Longevity Paradox
• Michie et al. (2011): The Behaviour Change Wheel, Health Psychology