Schools can play an important role in helping young people to stay healthy, especially as they reach adolescence and are tempted by risky behaviour.
There is a strong association between a student's sense of belonging to a school and their well-being, according to the latest annual report on young people's health from the chief medical officer of England, Professor Dame Sally Davies.
Smoking is a particular area of concern in the report, entitled Our Children Deserve Better: prevention pays, even though the numbers of young people taking up the habit have fallen in recent years.
Russell Viner, professor of adolescent health at University College London's Institute of Child Health, has said that adolescence is the most significant period in terms of adopting behaviours that can affect long- term health.
In a chapter within the chief medical officer's report, he states: "Smoking in the UK leaps up from a population prevalence of 1 per cent at 11 years to around 20 per cent at 15 years. In fact, nearly 90 per cent of lifetime smoking is initiated between the ages of 10 and 20 years in the UK."
Intervening during adolescence is an important way of preventing future ill-heath, he adds.
In a pioneering measure, Australia introduced plain cigarette packets in December 2012. The packets are standardised and carry large, graphic health warnings.
In the US, warning images have been used since 2009, but last year an appeals court ruled against plans to put nine graphic pictures, including a dead body, on cigarette packets.
Worldwide 150m - young people are estimated to be using tobacco (2). Teenage smokers suffer from shortness of breath almost three times as often as teenagers who don't smoke (3)
In the US (4)
Age at which 30- to 39-year-olds started smoking daily (2010)
10 or under 0.4%
11 or under 0.7%
12 or under 1.8%
13 or under 3.5%
14 or under 6.0%
15 or under 10.5%
16 or under 15.3%
1 Source: Smoking, Drinking and Drug Use Among Young People in England in 2012 (2013), Health and Social Care Information Centre. bit.lySmokingEngland
2 Source: Young People: health risks and solutions, factsheet 345 (2011), World Health Organisation. bit.lyWorldwideSmoking
3 Source: Health Effects of Smoking Among Young People, Tobacco Free Initiative, World Health Organisation. bit.lySmokingHealth
4 Source: Preventing Tobacco Use Among Youth and Young Adults (2012), Centers for Disease Control and Prevention. 1.usa.govFirstCigarette