Longevity

Healthspan versus lifespan: the years that count

Lifespan is how many years you live; healthspan is how many of them you live in good health. WHO estimates put global life expectancy at 73.1 years in 2019 and healthy life expectancy at 63.5, a gap of 9.6 years that a 2024 analysis of 183 countries found had widened by 13% since 2000, reaching 12.4 years in the US and 11.3 in the UK. Women carry 2.4 more years of poor health than men on average. Habits move the number: among 111,562 US health professionals, those with 4 or 5 healthy habits at age 50 could expect roughly 8 to 11 more years free of cancer, cardiovascular disease and diabetes than those with none.

What lifespan and healthspan measure

Life expectancy at birth is the average years a newborn would live if the death rates of one year applied for its whole life. Healthspan has no single agreed definition, so the WHO uses a proxy, healthy life expectancy or HALE, which weights each year by health status and in effect counts the years lived without disability. Life expectancy minus HALE is the healthspan-lifespan gap: the average years spent with disease or disability.

Between 2000 and 2019 global life expectancy rose from 66.8 to 73.1 years, a gain of 6.4 years. HALE rose from 58.1 to 63.5, up 9% but only 5.3 years, and the WHO says why: the gain came from falling mortality rather than from fewer years lived with disability. The pandemic then reversed roughly a decade of progress in 2 years: by 2020 both figures were back at their 2016 levels (72.5 and 62.8 years), by 2021 at their 2012 levels (71.4 and 61.9). The gap barely moved, at about 9.5 years, because both fell together.

The WHO fact sheet on ageing (1 October 2025) draws the uncomfortable conclusion: the proportion of life spent in good health has stayed broadly constant, so the added years are mostly years in poor health. By 2030, 1 in 6 people will be aged 60 or over, 1.4 billion people against 1 billion in 2020, and 2.1 billion by 2050; those aged 80 or over will triple to 426 million.

The gap country by country

The most complete comparison to date, by Garmany and Terzic in JAMA Network Open in December 2024, traced life expectancy and HALE for all 183 WHO member states from 2000 to 2019 using WHO Global Health Observatory data. In their dataset life expectancy grew by 6.5 years over the 2 decades and HALE by 5.4 (the WHO has since revised these to 6.4 and 5.3), so the gap climbed from 8.5 years in 2000 to 9.6 in 2019, an increase of 13%.

Averaged across the 183 states, HALE was 63.3 years against a life expectancy of 72.5, a mean gap of 9.2 years. The five widest gaps were all in wealthy, long-lived countries: the United States at 12.4 years, Australia at 12.1, New Zealand at 11.8, the United Kingdom at 11.3 and Norway at 11.2. The narrowest were Lesotho at 6.5, the Central African Republic at 6.7 and Somalia and Kiribati at 6.8.

The ordering is not a paradox. The gap rose with life expectancy and tracked the burden of noncommunicable disease, which explained 55% of the variation between countries (R squared 0.55); years of life lost to early death pulled the other way. Where fewer people die young from infection, childbirth or injury, more live long enough to accumulate diabetes, arthritis, heart disease and dementia. A narrow gap in Lesotho is not good news; a wide gap in Norway is partly the price of a long life.

The United States shows the mechanism. Its gap widened from 10.9 to 12.4 years, 29% above the global mean; life expectancy rose from 79.2 to 80.7 years in women and from 74.1 to 76.3 in men, yet HALE was unchanged in women and rose only 0.6 years in men. Almost every added year was a year in poor health.

Why women carry a wider gap

Across the 183 states, women's gap was on average 2.4 years wider than men's (standard deviation 0.5). The disparity was largest in Germany at 3.6 years, then Spain at 3.4 and France at 3.3, and smallest in Brunei at 1.0 year. Part of the explanation is longevity itself: women's mean life expectancy across member states was 75.0 years against 70.1 for men, and more years lived means more years in which chronic disease can accumulate. The sex difference in the gap also tracked the sex difference in noncommunicable disease burden, but longevity and disease burden each explained only about a fifth of the variation (R squared 0.21 and 0.22), so much of it remains unexplained.

In the United States, women's gap grew from 12.2 to 13.7 years, 2.6 years more than men's. If you are a woman, the extra years are real, but on average a larger share of them come with the conditions the WHO lists as typical of older age: osteoarthritis, back and neck pain, hearing loss, cataracts, depression and dementia. One caution: HALE is built from surveys and disability weights, so differences in how conditions are reported can move a measured gap without any change in health.

What mid-life habits change

National averages do not say what one person can expect. The closest answer is a 2020 BMJ study by Li and colleagues, which followed 73,196 women in the Nurses' Health Study (1980 to 2014) and 38,366 men in the Health Professionals Follow-Up Study (1986 to 2014), up to 34 years, recording 34,383 deaths. It scored five low-risk factors, four of them never smoking, a body mass index of 18.5 to 24.9, at least 30 minutes a day of moderate to vigorous activity (3.5 hours a week) and a diet quality score in the top 40%, and measured life expectancy free of cancer, cardiovascular disease and type 2 diabetes.

At age 50, women with none of the factors could expect 23.7 more disease-free years; women with 4 or 5 could expect 34.4. For men the figures were 23.5 and 31.1. Total life expectancy at 50 rose as well, from 31.7 to 41.1 years in women and from 31.3 to 39.4 in men, and the share of remaining life free of the three diseases rose from 74.8% to 83.6% in women and from 75.3% to 79.0% in men. Note that in men the years lived with disease stayed at roughly 8 (7.8 against 8.3) whatever the habits, so the gain was healthy years added in front; in women the disease years shrank from 8.0 to 6.7. Heavy smokers of 15 or more cigarettes a day and people with a BMI of 30 or more had the lowest share of disease-free years, 75% or less.

Movement is the factor most people can change this week. The WHO recommends at least 150 minutes of moderate-intensity activity a week, and its fact sheet of 26 June 2024 reports that 31% of adults worldwide, 1.8 billion people, do not reach it, up 5 percentage points between 2010 and 2022. Insufficiently active people have a 20% to 30% higher risk of death, and inactivity rises after 60 in both sexes. Our guides on how many steps a day and strength training after 40 turn the minutes into a week, and the Longevity Habits Score lets you tally your own factors.

What the numbers cannot tell you

Both headline studies have limits. The 183-country analysis is cross-sectional and rests on modelled WHO estimates: a gap of 9.6 years is a population average, not a forecast for you. The BMJ cohorts relied on self-reported habits, counted only 3 diseases and consisted of 94% to 98% white health professionals, so the figures may not transfer to other groups. All of it is association; the authors argue that only a very strong unmeasured factor could explain differences this large, but it is not a randomised trial.

The WHO makes the point that matters most for an individual: there is no typical older person. Some 80-year-olds have physical and mental capacities similar to many 30-year-olds, and most of that variation is down to environment and behaviour rather than genes. For your own healthspan, measurable markers beat any national average: grip strength, walking speed and VO2 max each predict years of independence, and what the longest-lived regions have in common shows what a small gap looks like in daily life.

See a doctor before you turn these figures into targets if you have diabetes, heart or kidney disease, take regular medication, are pregnant, are under 18, or have a history of disordered eating. A BMI range or an activity dose from a cohort study is a description of 111,562 health professionals, not a prescription, and blood pressure or blood sugar medication may need adjusting when your activity or weight changes. If you smoke, stopping is the largest single lever in the data, and your GP can help.

Habits linked to more disease-free years

Frequently asked

What is the difference between healthspan and lifespan?

Lifespan, or life expectancy, counts every year lived; healthspan counts the years lived in good health, which the WHO measures as healthy life expectancy (HALE). In 2019 the global figures were 73.1 and 63.5 years, so the average person spends about 9.6 years with disease or disability.

Is the healthspan gap getting bigger?

Yes. Across 183 WHO member states the gap widened from 8.5 years in 2000 to 9.6 years in 2019, a 13% increase, because life expectancy grew by about 6.5 years while healthy life expectancy grew by about 5.4.

Why is the gap widest in countries like the US and the UK?

Because long life and chronic disease go together. The gap rose with life expectancy and tracked the burden of noncommunicable disease, which explained 55% of the variation between countries. The US gap was 12.4 years, the UK 11.3 and Lesotho 6.5.

Why do women have a wider gap than men?

Women's gap was 2.4 years wider on average, and 3.6 years wider in Germany. Women live longer (75.0 against 70.1 years across member states), so chronic conditions have more years to accumulate, and their noncommunicable disease burden is higher; a large part of the difference is still unexplained.

Can healthy habits really add disease-free years?

In 111,562 US health professionals, women with 4 or 5 low-risk habits at age 50 had 34.4 disease-free years ahead against 23.7 with none, and men 31.1 against 23.5. The data are self-reported and observational, so they show a strong association rather than proof of cause.

Did the pandemic change the numbers?

It cut both. By 2021 global life expectancy had fallen to 71.4 years and healthy life expectancy to 61.9, the levels of 2012, but because both fell together the gap stayed at about 9.5 years.

Sources

• Garmany and Terzic 2024, JAMA Network Open: Global healthspan-lifespan gaps among 183 World Health Organization member states · Cross-sectional analysis of WHO Global Health Observatory data 2000 to 2019; global gap 8.5 to 9.6 years (13% increase); mean HALE 63.3 against life expectancy 72.5; US 12.4, Australia 12.1, New Zealand 11.8, UK 11.3, Norway 11.2; Lesotho 6.5, Central African Republic 6.7; women 2.4 years wider, Germany 3.6; R squared 0.55 with noncommunicable disease burden; US gap 10.9 to 12.4, women 12.2 to 13.7. Open access copy on PubMed Central
• WHO Global Health Observatory: Life expectancy and healthy life expectancy, Global Health Estimates 2000 to 2021 · Global life expectancy 66.8 (2000), 73.1 (2019), 72.5 (2020), 71.4 (2021); HALE 58.1, 63.5, 62.8, 61.9; gains of 6.4 and 5.3 years, HALE up 9%, driven by lower mortality rather than fewer years with disability; pandemic rolled both back to 2016 then 2012 levels
• WHO fact sheet, 1 October 2025: Ageing and health · 1 in 6 people aged 60 or over by 2030; 1 billion (2020) to 1.4 billion (2030) to 2.1 billion (2050); people aged 80 or over to triple to 426 million; proportion of life in good health broadly constant, so added years are in poor health; common conditions of older age; some 80-year-olds have capacities similar to many 30-year-olds
• Li et al. 2020, BMJ: Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes, prospective cohort study · Nurses' Health Study 73,196 women (1980 to 2014) and Health Professionals Follow-Up Study 38,366 men (1986 to 2014), 34,383 deaths; disease-free life expectancy at 50: women 23.7 with 0 factors to 34.4 with 4 or 5, men 23.5 to 31.1; total life expectancy at 50 women 31.7 to 41.1, men 31.3 to 39.4; disease-free share 74.8% to 83.6% (women), 75.3% to 79.0% (men); heavy smokers and BMI 30 or more at 75% or less; self-reported, mostly white health professionals. Open access copy on PubMed Central
• WHO fact sheet, 26 June 2024: Physical activity · At least 150 minutes of moderate-intensity activity a week for adults; 31% of adults (1.8 billion) inactive in 2022, up 5 percentage points since 2010, projected 35% by 2030; insufficiently active people have a 20% to 30% higher risk of death; women 5 points less active than men; inactivity rises after age 60; muscle strengthening benefits everyone

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This guide is for general information. It does not replace medical advice or an examination.