The study by health science specialists at the US Department of Veterans Affairs involved more than 700,000 veterans.

It found that adopting all eight healthy lifestyle habits by middle age, deemed to be age 40, could add an average of 24 years to a man’s life, and 21 years to a woman’s.

The authors suggest that by focusing on lifestyle medicine, a young branch of medicine that seeks “to maintain optimal health and to prevent, treat and reverse chronic illness across all life stages”, we can all live longer, healthier lives.

Combined, the habits listed below emphasise the importance of good nutrition, good sleep hygiene, stress management, having sufficient physical activity and maintaining social connections.

1. Get moving

There are many benefits of regular exercise. Aim for at least 150 minutes of moderate-to-vigorous exercise each week, including strength training on at least two or three days. Strength training is particularly important for older individuals, to build bone density and increase flexibility.

“A lifelong practice that combines resistance training and aerobic exercise delivers a massive improvement to both the quality and length of our lives,” he says. “Be active – sedentary is death.”

2. Avoid opioid addiction

Other opioids include oxycodone, morphine, tramadol and codeine.

According to a World Health Organization study, countries with the highest reported risk for abuse of the five opioid drugs listed above include the United States, United Kingdom, Germany, France, Canada and Australia.

3. Don’t smoke

In Hong Kong, smoking rates have fallen: it is estimated that only 9.5 per cent of people are daily cigarette smokers now.

4. Manage stress

Medical research estimates as much as 90 per cent of illness and disease is stress-related.

The damaging effects of chronic stress are many: among them are insomnia, hair loss, headaches and dangerous levels of inflammation.

Hongkongers are experiencing higher stress levels than people in other Asian countries. Among the 1,000 Hong Kong people surveyed in the 2022 Cigna 360 Global Wellbeing Survey, nearly nine in 10 respondents (87 per cent) said they felt stressed – and 19 per cent of them found this stress “unmanageable”.

The top three stressors? Uncertainty about the future (40 per cent), concern about personal finances (34 per cent) and a heavy workload (22 per cent).

5. Eat healthily

A healthy diet and a healthy lifestyle go hand in hand. Studies show eating more plant foods instead of processed foods lowers your risk of developing serious illness.

Seven science-backed benefits of this type of diet include safeguarding heart health, strengthening the immune system, boosting energy, keeping the gut healthy, aiding in weight loss, warding off cancer, and preventing and treating diabetes.

“Key factors involve eating an appropriate number of calories to maintain a healthy weight, focusing on whole foods, getting plenty of protein for muscle maintenance [or growth] and avoiding processed foods,” Price says.

6. Don’t binge drink

Hong Kong’s Centre for Health Protection defines binge drinking as having at least “five cans of beer, five glasses of table wines, or five pegs (60ml or 2oz) of spirits in one sitting”.

Even having less than that can trigger health problems, though. According to the US Centres for Disease Control and Prevention, these include: high blood pressure, heart disease, stroke, liver disease and digestive problems; cancer of the breast, mouth, throat, oesophagus, voice box, liver, colon and rectum; weakening of the immune system, increasing the chances of getting sick; and learning and memory problems, including dementia and poor school performance.

7. Get a good night’s sleep

Advice varies on the optimal amount of sleep needed for a healthy adult but tends to converge on seven to eight hours a night. For teenagers, it’s eight to 10 hours.

The average Hongkonger is chronically sleep deprived.

Sleep deprivation is intimately associated with poorer eating habits and a higher body mass index (BMI).

Your bedroom should be a place free of digital devices. No TVs. No laptops. And, if possible, no phones.

8. Maintain positive social relationships

Strong social connections act as a buffer against stress and the deleterious effects of anxiety and depression.

In Hong Kong, an increasing number of individuals, particularly elderly individuals, are living more isolated existences.

As we age, maintaining friendships helps keep our brains sharp. Isolated individuals face a significantly greater risk of brain shrinkage, according to a recent study by the American Academy of Neurology.

“Social connectedness with the people you love is the strongest predictor of longevity,” Price says. “We need a sense of contributing something of value to the world.”

Inactivity among highest risk factors

Among the study participants, being inactive, using opioids and smoking had the biggest impact on lifespan: these three factors were associated with a 30 to 45 per cent higher risk of death during the study period.

Stress, binge-drinking, poor diet and poor sleep habits were each linked to about a 20 per cent increase in the risk of death. A lack of positive social relationships was associated with a 5 per cent increased risk.

“Our research findings suggest that adopting a healthy lifestyle is important for both public health and personal wellness,” noted Xuan-Mai Nguyen, a health science specialist at the Department of Veterans Affairs and one of the study authors.

“The earlier the better, but even if you only make a small change in your 40s, 50s or 60s, it still is beneficial.”