Rome, November 15 - A study Thursday showed young southern Italians smoke, change partners and consume marijuana more often than their peers in the north, while northerners drink alcohol, consume cocaine and stick with their partners more often than the rest of the country. The results were part of a study by the government-sponsored Androlife campaign, presented Thursday at a convention on sexually transmitted diseases (STDs) in Lecce. The study showed that people between 18 and 35 in both the north and south are equally susceptible to STDs. "The data are very important given STDs are on the rise in Italy," said Carlo Foresta, director of the department of reproductive pathology at the University of Padua and president of STD prevention group SIAMS. "It's clear that sexual behavior is much freer among young people in the south, who tend to have a higher number of partners". The study showed that young people in the south tended to use protection only 50% of the time. Youths in the south also tend to engage in less physical activity and suffer from a higher obesity rate, while northerners are more active and slimmer. "Obesity can be considered a reproductive risk factor among youth," said Foresta. "It is often the cause of diseases such as hypogonadism," which is diminished functional activity of the testes and ovaries.