Healthy eating, regular activity, a healthy body weight, not smoking and moderate alcohol intake were the five lifestyle factors examined in Harvard-led research published in Circulation in 2018. This is the widely cited study behind the “five habits for a longer life” headline.
What the researchers studied
The analysis used long-term data from 78,865 women in the Nurses’ Health Study and 44,354 men in the Health Professionals Follow-up Study, with follow-up extending to 34 and 27 years, respectively. Researchers examined lifestyle patterns and mortality, then estimated remaining life expectancy at age 50.
The study was observational. Participants were not randomly assigned to these habits. Differences in health, circumstances and other behaviors can influence the results even after statistical adjustment. An association is meaningful evidence, but it does not prove that adopting this checklist will add exactly 12 or 14 years to any one person’s life.
1. Eat a healthy diet
Diet quality was assessed using a healthy-eating index, rather than a particular branded diet. For everyday meal planning, Harvard’s nutrition guidance emphasizes vegetables, fruits, whole grains, legumes, nuts and healthier protein and fat sources. Harvard’s Healthy Longevity guide
Try this: Choose one meal you eat frequently and improve it. Add vegetables to lunch, use beans in a regular dinner or keep fruit and unsalted nuts available for snacks. A repeatable grocery list is more useful than an elaborate plan you abandon after a week.
2. Move regularly
The study’s activity criterion was at least 30 minutes a day of moderate-to-vigorous physical activity. This describes the research threshold; it does not mean someone starting from inactivity must immediately complete a demanding workout every day.
Try this: Put movement on your calendar and choose an activity you can repeat. Start with a manageable walk and build gradually. If you already lift weights, keep aerobic activity in the picture too. Our cardio guide and strength-training article offer practical next steps.
3. Maintain a healthy body weight
The research defined its low-risk weight category as a body mass index of 18.5–24.9. That is a study definition, not a complete assessment of an individual. BMI does not distinguish muscle from fat; a muscular person should not treat the cutoff as a diagnosis.
Try this: Discuss your weight alongside waist measurement, strength, blood pressure and metabolic markers with your clinician. If weight loss is appropriate, ask for a plan that preserves muscle and is realistic for your life. Avoid turning a single number into the entire goal.
4. Do not smoke
The original low-risk smoking factor was never smoking. That classification describes the analysis; it does not mean a former smoker has missed the opportunity to improve health. Harvard’s longevity guidance also emphasizes smoking cessation.
Try this: If you smoke, make getting help to quit a priority. Ask a clinician or pharmacist about cessation support instead of relying solely on willpower. If you have already quit, maintaining that change deserves recognition even though the study’s scoring cannot capture every personal success.
5. Be careful with alcohol
The original study counted moderate alcohol intake as a low-risk factor. That finding needs context: observational comparisons do not establish that alcohol itself extends life.
Try this: Notice how often alcohol appears in your routine and consider alcohol-free alternatives. You do not need to add wine to an otherwise healthy lifestyle to complete a five-item checklist.
More healthy years: the 2020 follow-up
A related Harvard-led study published in BMJ in 2020 examined years lived without cancer, cardiovascular disease or type 2 diabetes. At age 50, women with four or five low-risk factors had an estimated 34.4 remaining years free of these diseases, versus 23.7 with none. For men, the figures were 31.1 versus 23.5 years.
That is approximately 10.7 additional disease-free years for women and 7.6 for men. It is a different outcome and comparison from the 2018 lifespan estimate. “Disease-free” here refers to those three disease groups, not freedom from every illness or disability. Harvard’s 2020 summary
Where to begin
Choose one change you can repeat this week. Write down when and where you will do it, remove one obstacle and review how it went. Keep the plan small enough to survive a busy day. Build the next habit once the first becomes more reliable.
These studies do not provide an exact forecast for someone beginning at 60 or 70. They do provide a useful reason to make everyday habits a priority. Sleep, social connection and preventive care still matter, even though they were not the five factors scored in this particular analysis.
The Biohack Journey perspective
The most useful question is not “How many years will this add?” It is “What can I make part of my normal life?” Choose food you enjoy, movement you can sustain and goals that support your health and independence. Use the research as direction, then adapt the plan to your circumstances.
Sources and further reading
- Li et al., Circulation (2018): Impact of Healthy Lifestyle Factors on Life Expectancies in the US Population
- Harvard Gazette: Five healthy habits to live by (2018)
- Li et al., BMJ (2020): Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes
- Harvard Chan: The healthspan follow-up (2020)
- Harvard Nutrition Source: Healthy Longevity
- WHO: Alcohol and health risks
Educational information, not individualized medical advice.