If you want a concrete number to aim at, the largest lifestyle analysis of U.S. veterans to date offers one: adopting eight specific healthy habits by age 40 was associated with a predicted 24 additional years of life for men and 21 for women, compared with people who had none of those habits. That finding comes from a study involving more than 700,000 U.S. veterans, reported by the American Society for Nutrition, and it reframes "healthy living" from vague advice into a quantified, cumulative payoff.
Before diving in, one honest caveat shapes everything that follows. These are observational results — statistical associations drawn from a large cohort, not proof that any single habit adds a fixed number of years for any individual. The veterans in the study also represent a specific population, so the averages may not transfer exactly to everyone. What the numbers do offer is a well-powered signal about which behaviors matter most, and how much they appear to matter together.
Introduction: The Power of Lifestyle for a Longer Life
Longevity research often feels abstract, but this study's scale makes it hard to dismiss. By following hundreds of thousands of veterans and comparing people with few or none of eight healthy lifestyle factors against those with all of them, the researchers could estimate differences in life expectancy that dwarf the effects of most individual interventions. The comparison group matters: the 24- and 21-year figures are relative to people with none of these habits, not relative to an average person.
The eight factors also span more of daily life than the usual "diet and exercise" framing. They include not only physical activity and diet, but also stress management, sleep hygiene, positive social relationships, freedom from opioid addiction, avoiding smoking, and not regularly binge drinking. That breadth is part of why the cumulative effect is so large — the habits touch mental health, social connection, and substance use alongside the familiar physical markers.
Eight Habits That Add Decades to Your Life
According to the study's results, as described by the American Society for Nutrition, men who had all eight habits at age 40 would be predicted to live an average of 24 years longer than men with none of them. For women, having all eight factors in middle age was associated with a predicted 21 additional years compared with women who had none. The study did not publish a year-by-year breakdown for each individual habit, so the honest way to read these figures is as a combined effect — the value of the full set of behaviors working together.
That combined framing has a practical upside: you don't need to guess which single habit is "the one." The evidence points to a cluster of behaviors, and adopting more of them appears to shift the prediction upward. The table below gathers the full list in one place so you can see the scope of what the researchers measured.
Cumulative Impact of Healthy Habits on Longevity and Healthcare Costs
The table below summarizes the eight lifestyle factors identified in the U.S. veterans study, along with the total predicted life expectancy gain for people who adopt all eight by age 40. Because the study reports the cumulative effect rather than per-habit figures, the years column applies to the full set of habits together, not to each row individually. The final rows add the financial dimension from a separate nationwide cohort study, which compared lifetime healthcare expenditures by smoking status and body weight.
| Healthy Habit | Brief Description | Predicted Additional Years of Life (by age 40) |
|---|---|---|
| Physical activity | Being physically active was one of the eight lifestyle factors associated with increased longevity. | Men: 24 years; Women: 21 years — predicted for those with all eight habits, compared with people who have none of them (cumulative; not broken down per habit). |
| No opioid addiction | Being free from opioid addiction was identified as a key lifestyle factor linked to a longer life. | |
| Not smoking | Not smoking was associated with both increased life expectancy and lower lifetime healthcare costs. | |
| Stress management | Managing stress effectively contributed to the study's longevity prediction. | |
| Good diet | Having a good diet was one of the eight essential lifestyle factors measured. | |
| No regular binge drinking | Not regularly binge drinking was counted among the healthy habits. | |
| Good sleep hygiene | Practicing good sleep hygiene was a factor in the life expectancy model. | |
| Positive social relationships | Having positive social relationships was linked to a longer life in the study. | |
| Lifetime healthcare expenditure comparison (nationwide cohort study) | Smokers: US $60,395 per capita vs. nonsmokers: US $58,821; nonoptimal body weight: US $62,474 vs. optimal body weight: US $53,336. | |
Reading the table this way makes the reasoning path explicit: the eight habits are the inputs the veterans study measured, the 24- and 21-year figures are the predicted output for adopting the full set by age 40, and the dollar figures show two of those same habits — not smoking and maintaining a healthy weight — carrying measurable financial weight in a separate national cohort.
Beyond Longevity: The Financial Benefits of Healthy Living
Years of life are the headline, but a nationwide cohort study published in the journal Medicine and archived by the U.S. National Library of Medicine adds a second ledger: lifetime healthcare spending. Its authors evaluated how healthy lifestyle factors affect expenditure over a lifetime and found that nonsmoking and a healthy weight were significantly associated with reduced lifetime healthcare costs.
The dollar differences are worth pausing over. Per capita estimated lifetime healthcare expenditures were US $60,395 for smokers versus US $58,821 for nonsmokers. For body weight, the gap was wider: individuals with nonoptimal body weight had an estimated US $62,474 in lifetime expenditures compared with US $53,336 for those with optimal body weight — a difference of more than $9,000 per person. Those are population-level averages, not personal bills, but they show the same habits that extend life also appear to shrink what it costs to maintain it.
Making the Change: Prioritizing Your Health Journey
How should you act on numbers this large? Start by noticing what the eight habits have in common: nearly all of them are modifiable, and none requires exotic interventions. Moving more, sleeping better, managing stress, eating well, avoiding smoking and binge drinking, and investing in relationships are all behaviors within most people's reach — and the study's framing suggests the gains come from stacking them, not perfecting one.
It also helps to be realistic about what the evidence can and cannot tell you. The veterans study predicts averages for a specific cohort, and it does not provide a per-habit year breakdown, so no single habit can honestly be labeled "worth X years." If you currently have none of the eight habits, the comparison baseline in the study is people like you — which means even partial adoption moves you along the same measured curve.
Your Path to a Longer, Healthier, and More Affordable Life
The practical decision this evidence supports is clear: prioritize and adopt the eight healthy lifestyle habits identified in the U.S. veterans study — especially physical activity, not smoking, and maintaining a healthy weight — to increase your predicted life expectancy and reduce lifetime healthcare costs. The payoff is twofold: the study associated the full set of habits with a predicted 24 extra years for men and 21 for women by age 40, while the expenditure analysis linked nonsmoking and optimal body weight to thousands of dollars less in lifetime healthcare spending.
The measurable indicator to watch is a noticeable improvement in your personal health metrics — BMI, activity levels, and sleep quality — alongside a reduction in healthcare-related expenses over time. Those are observable, trackable outcomes, and they map directly onto the factors the research actually measured. You don't need to adopt all eight habits tomorrow; you need to start moving the ones you can measure.
