A new study has said that nearly every adult in Scotland is burdened with at least one major lifestyle risk factor, and 55 percent of the population are coping with three or more.
Looking at five health-threatening behaviours -- smoking, heavy drinking, lack of exercise, poor diet, obesity -- researchers found that twice as many Scottish men and women face a triple threat or worse than in any continental European country in which a similar study has been done.
Only in England and the United States are levels of risk even remotely close.
"Only 2.5 percent of the population have no risk factors at all. It is frightening," he said in a phone interview, noting that the comparable figure in other rich nations was generally six or seven percent.
Published in the peer-reviewed journal BMC Public Health, the study contributes to a growing interest in the accumulated impact of harmful lifestyle choices, Conway said.
Up to now, most research has focused only on individual risk factors, one at a time -- smoking or drinking or overeating.
"But unhealthy behaviours cluster. And the combination is synergistic, which increases the overall risk disproportionately," he said.
This has major implications for both healthcare systems and individuals trying to reduce their exposure to lifestyle disease.
"When people have combined risk factors, it might be better to take a more holistic -- or 'whole patient' -- approach," he added.
To measure the scope of the problem, Conway and colleagues sifted through the 2003 Scottish Health Survey. Full data on the five risk factors under review was available for 6,574 men and women.
The researchers created a 'yes' or 'no' threshold to determine whether an individual faced a given lifestyle-related health threat.
For tobacco, for example, all smokers were considered to be at risk, while never and ex-smokers were not.
The UK Royal College of Physicians' definition of "sensible drinking" -- set at 30 milligrams (24 grams) of pure alcohol per day for men, and 20 milligrams (16 grams) for women -- was the cutoff for heavy consumption.
For excess fat, the tipping point was a "body-mass index" (BMI) over 25, widely viewed as the threshold for being "overweight." Above 30, one is obese.
While he was braced for a grim picture, even Conway was startled by the results.
More than 85 percent of adults had at least two risk factors, 55 percent had three or more, and nearly a fifth had four or all five.
The most prevalent single lifestyle menace, affecting four out of five people, was poor diet -- not enough fruit and vegetables.
Ten percent of respondents were both smokers and heavy drinkers, and three-quarters of these had picked up an additional two or three health threats as well.
The main drivers of these accumulated risks appeared to be social and economic.
Those living in the most deprived areas and with poorest educational qualifications had a much greater probability of piling up unhealthful lifestyles.
Countries with smaller disparities in income and social levels, Conway noted, also had fewer people with an accumulation of health-wreaking habits.
"Our findings suggest we should tackle some of the social drivers. Instead of just trying to address the behaviours, perhaps we could try to address the inequalities too," he said.