The number of teenagers trying cigarettes or alcohol before they turn 14 has dropped, especially among girls, suggests a World Health Organization study of 42 well-off nations.
From 2010 to 2014, the percentage of 15-year-old boys in Europe, Canada and Israel who said they'd smoked their first cigarette at 13 fell from 26 to 22 among boys -- but plunged from 22 to 13 for girls.
Alcohol use among young teens in the 42 countries canvassed also went down over the same period, by about 10 percent.
"Health behaviours along with social habits and attitudes acquired in the critical second decade of a young person's life can carry on into adulthood and affect the entire life-course," said Zsuzsanna Jakab, WHO regional director for Europe.
"A good start can last a lifetime," she said in a statement. Conducted every four years, the survey examines self-perception and risky behaviour among 11-, 13- and 15-year olds.
Greenland, Lithuania, Estonia, Latvia and the Czech Republic topped the list of young smokers in 2014, with 38 to 56 percent of boys, and 36 to 53 percent of girls, saying they had already lit up by age 13.
The countries with the lowest rates of reported tobacco use at the same age were Iceland, Albania, Canada, Norway and Spain. In Europe, 16 percent of all deaths in adults over 30 are due to tobacco -- the highest rate of all WHO regions.
Studies have shown that exposure to nicotine during adolescence can have lasting effect on brain development. Most countries have taken steps to discourage teens from smoking, including banning point-of-sale displays, aggressive public service campaigns, and stiff taxes.
France, Ireland and Britain are also moving toward plain packaging. Bulgaria tops the list for regular drinking among early teens, with 13 and 20 percent of 13-year-old girls and boys respectively saying they consume alcohol at least one a week.
- Boys fat, girls think they are -
By age 15, those percentages have climbed to 17 and 32 respectively. Romania, Albania, Croatia, Greece and Italy fill out the top of the list, while Norway, Iceland, Ireland, Netherlands and Spain have the most abstemious adolescents.
When it came to getting flat-out drunk, Denmark topped the ranking of 15-year-olds -- nearly 40 percent -- who had been plastered at least twice, with Hungary, Lithuania, Bulgaria and Scotland rounding out the top five.
England had the distinction of being the only country in which a higher percentage of girls (31) had been seriously boozed up than boys (25). The Health Behaviour in School-aged Children survey also gathered statistics on obesity -- an objective measure -- as well as how teens felt about their weight, a subjective one.
The numbers in both categories are very different for boys and girls. At eleven years old, more than 25 percent of boys are obese or overweight in three-quarters of the countries surveyed.
That figure drops to half of the countries at age 13, and about a quarter at age 15. For the opposite sex, however, there is no nation in which more than 25 percent of girls -- in any age bracket -- tip the scales that far, except one: Malta.
The other countries with the chubbiest youngsters are Greece, Canada, Greenland and Bulgaria. In all nations and age categories but one -- Ireland, at age 11 -- more boys than girls carried too much weight, usually by a large margin.
Despite that imbalance, however, a higher percentage of girls in all 42 countries said that they thought they were too fat. The older they got, the higher that gender gap in self-perception became.
By age 15, more than 50 percent of girls in 14 nations said they needed to shed pounds or kilos, including England, Germany, Netherlands, Belgium and -- topping the list at 61 percent -- Poland. "Girls are more likely to be discontented with their body weight regardless of country or region," the report noted.