Many research studies have shown the dangers of smoking cigarettes, but the effects of hookah smoking have not been studied extensively.A new study of 9,840 people in Iran has found that hookah smokers are at greater risk of diabetes and obesity.One hookah session could be equivalent to smoking a whole pack of cigarettes, study co-author Gordon Ferns said.The rate of obesity and diabetes is "significantly higher" among hookah smokers than cigarette smokers, according to a new study of nearly 10,000 people.While the dangers of smoking cigarettes have been well documented, little research exists on hookah smoking, which is the second-most common way of smoking tobacco. The new study, published in the journal Diabetology and Metabolic Syndrome, looked at the smoking history of 9,840 Iranian participants between the ages of 35 and 65.Roughly 6,700 of the participants do not smoke, more than 800 smoke cigarettes, and over 1,000 said they smoke hookah. The researchers say this is the largest study to explore the negative effects of smoking hookah.Their findings cast doubt on some people's belief that hookah is less dangerous than cigarettes."We found that the adverse effects of hookah smoking could be even greater than cigarette," the study said.Co-author Gordon Ferns, a professor of metabolic medicine at the Brighton and Sussex Medical School in the United Kingdom, told The Telegraph that one hookah session could be equivalent to smoking more than a pack of cigarettes.Read more: Hookah is not harmless, experts sayIt takes an average of 20 puffs to finish a cigarette, but hookah can last much longer and cause people to inhale a higher amount of carcinogenic substances.Ferns told The Telegraph that it is important for the public to understand the dangers of smoking hookah, particularly young people who may be more drawn to flavored tobacco.A 2018 study found that only 11% of US students between sixth and 12th grade have tried hookah. More than 50% of teens, however, overestimate how often their friends smoke hookah, and the study says teens are nine times more likely to try it if they think their peers are smoking too.It's still not clear why hookah smoking is linked to diabetes, but Ferns said it's possible that smoke toxins trigger an inflammatory response that makes people's tissues resistant to insulin. He said hookah smoking may be connected to other social behaviors that cause weight gain."The risks of hookah smoking with respect to some types of cancer is well established, and the evidence for an association with cardiovascular disease is growing," Ferns told The Telegraph.Read more about hookah smoking:Smoking Hookah Is Terrible For YouHookah Smokers Are Inhaling BenzeneHookah use tied to exposure to cancer-causing compoundsJoin the conversation about this storyNOW WATCH: Why Harvard scientists think this interstellar object might be an alien spacecraft Click here to read full news..