Young Scots are more satisfied with their life than their contemporaries across Europe according to a major study.

The survey, carried out by the University of St Andrews for the World Health Organisation, also found general improvements in diet as well as reduced rates in smoking, drug and alcohol consumption amongst Scots between the ages of 11 and 15.

Researchers also found that a quarter of 15-year-old girls and almost a third of 15-year-old boys (29%) drink alcohol every week - the eighth highest proportion in the survey.

In Scotland, 22% of 15-year-olds said they first got drunk at the age of 13 or younger, and 16% of 13-year-old girls and 14% of boys the same age have been drunk at least twice. Meanwhile, 14% of 15-year-olds (15% of girls and 12% of boys) say they drink spirits every week.

Just three countries, Greece, Austria and Spain, have higher proportions of teenagers this age drinking spirits.

The figures were revealed in the 2009-10 Health Behaviour of School-aged Children study, in which a total of 207,334 young people aged 11, 13 and 15, including 6738 in Scotland, were questioned. The survey covered 43 countries and regions across Europe and North America.

The research also finds that in Scotland, 35% of 15-year-old girls and 27% of boys the same age have had sexual intercourse, the seventh highest proportion in the survey.

High levels of happiness was recorded among young people, with 90% of 11-year-old girls and 92% of boys the same age reporting "high life satisfaction", giving Scotland the ninth highest proportion in the survey and the highest level in the British Isles.

However, 34% of 15-year-old girls and 22% of boys the same age rate their health as being only fair or poor, making Scotland second to Ukraine for this.

Of the same age, just 8% of girls and 13% of boys say they do at least one hour of moderate to vigorous physical activity every day. Scotland is sixth from bottom for this.

A Scottish Government spokeswoman said the report highlights "areas where we know work remains to be done".

She added: "We have a range of measures in place to help tackle issues like underage drinking, sexual health and physical activity."

The spokeswoman said: "In particular, we have launched our Take Life On initiative to highlight simple steps parents can take to help their children get active and achieve health benefits as a result.

"We are also seeing a decline in the proportion of 13-year-olds and 15-year-olds who have ever had an alcoholic drink, and our alcohol framework outlines a series of measures to protect our children and young people from the harm caused by alcohol misuse and to support them to make positive choices."

She continued: "Sexual health continues to be a high priority for the Scottish Government and we are working closely with local authorities and other partners to ensure that all young people, parents and carers have access to high-quality and consistent information on sexual health and well-being."

However, the spokeswoman said: "It is good news that young Scots are among the happiest in Europe and see themselves performing well at school.

"Reductions in cannabis use, smoking, soft drinks consumption and an increase in toothbrushing are all to be welcomed and show that the action that the Scottish Government and our partners are taking in these areas is starting to bear fruit."

The survey shows that among 11-year-olds, 50% of girls and 42% of boys eat fruit every day, although this falls to a respective 34% and 26% for 15-year-olds.

Meanwhile, 15% of girls aged 11 and 18% of boys aged 11 drink soft drinks every, as do 21% of girls and 32% of boys aged 15.

Of the 11-year-olds surveyed, four-fifths of girls (80%) and two-thirds of boys (68%) brush their teeth more than once a day, the ninth highest proportion in the survey. Of those aged 15, 83% of girls and 63% of boys do the same, again the ninth highest.

A total of 15% of girls aged 15 and 22% of boys aged 15 have smoked cannabis, with 6% of the girls and 12% of the boys having used the drug in the last month from when they were questioned.