JERUSALEM — A new World Health Organization report finds Israeli youth less happy than their counterparts in 27 other countries in Europe and North America — and shows that many are sexually active by age 15.

WHO's "Health Behavior in School-Aged Children" report — www.who.int/dsa/justpub/justpub.htm — gives Israel an unsatisfactory grade for its efforts to promote health and healthy behavior among its youth.

More than 5,000 Israeli children aged 11, 13 and 15 were sampled by the cross-national survey.

In an examination of how pupils feel about their lives, the report finds "the least happy… are those from Israel."

Only 62 percent of Israeli youth reported feeling "very happy" or "quite happy." The most positive feelings came from youth in Scandinavia. Ninety-two percent were "very happy" or "quite happy."

Israeli youth had the highest rate of feeling low — more than two-fifths — compared to minimal rates in Austria, Portugal and Greenland. Israeli kids complained about loneliness at a rate much higher than those in all other countries, except for Portugal.

Israeli youth were more likely to eat junk food and sweets, drink beer at a young age, get little exercise, watch too much TV, observe poor dental hygiene, smoke and take pills for nervousness.

However, they were also less likely to get drunk, feel estranged from their parents or have sex without a condom than their counterparts in Europe and North America.

Dr. Alex Levinthal, director of the Israeli Health Ministry's public health department, had not yet read the report.

Nevertheless, having read the previous study issued four years ago, Levinthal said the new document might be inaccurate.

"Studies we know of show Israeli youths are different than in other countries," he said. "They exaggerate when asked about their behavior. When asked how many beers they drink, they'll say double the real figure. The data must be verified by other means to show it is accurate."

He added that Jewish children in ultra-religious families are not included in Israeli surveys for WHO. Only Jews going to state secular and state religious schools and Arabs are included.

Dr. Yossi Harel, head of Bar-Ilan University's sociology department who led the Israeli survey team, dismissed such arguments.

"It is not true that Israeli kids are any different in their self-reporting on behaviors. Studies have not shown that they answer in a different way than their counterparts in other countries."

Noting that Israeli society has "neglected the well-being of its youth for years," he called for urgent national programs to promote health among teenagers.

According to the WHO study, pupils in "Israel and the U.S. report the highest frequency of health-related problems and symptoms. Of nine pain and negative-feeling symptoms, Israel has the highest percentages for five variables and is among the top four for all of the others, except tiredness in the morning."

However, Israel headed the list of countries in which pupils live with both their parents and did very well in the ability to talk to their fathers, although less well in talking to their mothers.

They were more likely than others to find it easy to make friends at school and to spend time with friends after school.

At the same time, they were at the top in complaining that they are "treated too strictly at school." Israeli pupils were also much more likely than most of the others to complain that their parents and teachers expect too much of them at school.

They were No. 2 or 3, depending on age, in watching TV four hours or more a day. They eat less fruit every day, and more chips and French fries than desirable.

Sixty-eight to 79 percent of Israeli youths said they consume soft drinks every day, while few admitted to drinking low-fat milk.

Asked about their sexual behavior, 44 percent of the Israeli 15-year-old secular Jewish boys and 11 percent of secular Jewish girls reported having had sex.

The mean age of sexual initiation was 15-1/2 years for girls and 14-1/2 for boys.

However, 76 percent of secular boys and 83 percent of secular girls having sex reported using condoms during intercourse.