Risky behaviour – smoking, illegal drug use, excessive drinking, unhealthy eating and unsafe sex – is on the rise worldwide and poses a growing threat to health, particularly in poorer countries, according to a World Bank report.

Smoking exacts a particularly high toll. Nearly 80% of the 6.3m deaths from smoking in 2010 occurred in middle- and low-income countries, says the Risking Your Health report.

Smoking is decreasing in richer countries but increasing in parts of the developing world. The Bank says low- and middle-income countries are in the grip of a tobacco epidemic, characterised by a sharp rise in smoking, particularly among men, after it peaked in rich countries in the 1960s and 70s.

In China, where smoking accounts for 1.2m deaths a year, it is the number one killer. In 2009, the country consumed more than 38% of the world's cigarettes, followed by Russia, the US, Indonesia and Japan.

The report finds that tobacco-related illnesses place a considerable financial burden on countries. The bank cites a study in Bangladesh that found families with at least one member afflicted by a tobacco-related illness, such as heart disease, lung cancer and oral cancer, spent 5.1% of their household monthly expenditure on tobacco and 10.2% on treating their illnesses.

In Vietnam, even after accounting for government subsidies, the out-of-pocket expenses for each hospital admission of lung cancer, chronic obstructive pulmonary disease and heart disease amounted to $285, or about 34%, of per capita gross domestic product.

In an area of Tanzania, health spending triggered by HIV and Aids was more than 70% greater than for other diseases over a two-year period. Together with funeral costs, this amounted to more than the annual household income.

"Individuals' risky behaviours that cluster among the poor ripple throughout entire populations, crippling families' potential and undermining the great health and economic progress we've seen in low- and middle-income countries in recent years," said Tim Evans, director of health, nutrition and population at the World Bank.

"Reversing the tide of these pernicious behaviours by promoting societal conditions for better health choices will pay dividends for families and countries across the globe, ultimately helping us end extreme poverty and promote inclusive and healthy growth."

Legislation and taxation, for example, tend to be effective, the report concludes, especially when combined with strong enforcement. Cash transfers have also proved to be promising in some settings. Behaviour change campaigns, such as school-based sex education and calorie-labelling laws, are often less effective on their own. Instead they benefit from being part of broader programmes to change risky behaviour.

Repeated messaging is effective, as with the case of graphic labelling on cigarette packets that reinforce the message to smokers each time they reach for a cigarette. Comprehensive advertising bans on cigarettes are more effective than partial bans.

While taxes on tobacco and alcohol can be shown to reduce consumption, particularly in richer countries, the evidence on behaviour change from tax on unhealthy foods is more mixed. A recent attempt by Denmark to tax high-fat food products increased prices by 9%, but the attempt failed, in part because consumers shopped across the border.

The report also notes fundamental differences in being able to change behaviour relating to alcohol, tobacco and food.

"People need to eat to survive, while they can abstain from tobacco and alcohol without health consequences," the report says. "Many unhealthy foods are inexpensive, while healthier foods are more expensive and require more time for shopping and cooking (cheap doughnut compared to expensive broccoli, for example) … Differentiated taxes could modify relative prices, but the broad range of healthy and unhealthy foods makes it difficult to avoid substitution among unhealthy foods."

Programmes tend to be more successful if they take into account local culture. Brazil successfully carried out a tobacco substitution programme as it involved the community in the choice of the substitute crop and method of farming. In contrast, Bolivia's coca substitution initiative met with less success as it was imposed on the community.

On HIV prevention, the report says the evidence on the efficacy of conditional cash transfers remains limited, but there have been some encouraging results. In Malawi, small financial incentives have been shown to increase the uptake of HIV testing and counselling. Another study in Malawi conducted similar transfers for adolescents in which cash was conditional on school attendance – in addition to increased enrolment and attendance, the programme caused a reduction in HIV and HSV-2 (herpes simplex virus–type 2, the common cause of genital herpes) incidence.