By Roxana Saberi
BBC News, Isfahan
For all the anti-American rhetoric uttered by Iran's regime, many Iranians have embraced at least one aspect of American culture - fast food.
Many citizens are trying to adopt a healthier way of living
More and more, Iranians are digging into cheeseburgers, chips and pizza in a country that is traditionally known for its kebabs, rice and savoury home-cooked dishes.
That may explain why obesity is on the rise in Iran, and heart disease and stroke are now the leading causes of death.
An Iranian group is on a campaign to make the country healthier. The Isfahan Healthy Heart Programme has been working with schools, businesses, and health professionals to promote healthy lifestyles.
"It was not popular for people to prefer junk food, fast food, 20 years ago," says Dr Nizal Sarrafzadegan, who founded the group with government help five years ago.
She was motivated by seeing firsthand the consequences of Iran's growing obesity epidemic at her Cardiovascular Research Centre in the central Iranian city of Isfahan.
"We have a high prevalence of hypertension and a high prevalence of diabetes, and smoking and high cholesterol," she says.
"We think this is the problem of a Western lifestyle that is affecting many developing countries in Asia, Latin America, everywhere, and unfortunately it's affecting children more than adults.
"Maybe there are some genetic factors, but we believe in environmental factors more."
Dr Sarrafzadegan says the change in eating habits has combined with other unhealthy changes in lifestyle.
Iranian children now watch an average of four hours of television a day, and adults drive cars more and exercise less than they used to.
More than 50% of Iranian adults are now overweight or obese, she says. To combat these problems, the Isfahan Healthy Heart Programme has tried to enlist the help of the entire community.
The programme has persuaded around 40 restaurants in Isfahan to offer low-fat, low-calorie meals in addition to their regular meals.
Activists want to extend Isfahan's programme nationwide
Healthy Heart stickers have become a common sight on display in the windows of Isfahan restaurants.
"We asked them to put more vegetables, to modify dressings of salad, so they use less mayonnaise nowadays," Dr Sarrafzadegan says. "We ask them to remove the salt shaker from tables unless someone asks for it."
Some businesses in Isfahan are also getting involved. Many of them now offer healthier lunches and regular medical checkups to their employees.
Mosques offer health education, and exercise classes have become more popular. The city has also agreed to ban private cars on some streets on certain days in order to encourage exercise and public transportation.
Health education was already a part of required pre-marriage classes.
But now, in addition to learning about birth control and sexually transmitted diseases, young men and women in Isfahan's classes also learn how to cook low-fat meals and stay fit.
"In our Iranian culture, women often stay home, which causes them to gain weight," said 25-year-old Zohre, a student in the class.
"Men have pressure at work, so they get heart problems. In our society, both men and women are exposed to unhealthy lifestyles.
"They said our diet should be full of vegetables and vitamins and that we should fry our food less often."
Dr Sarrafzadegan says her Healthy Heart Programme is working. Preliminary results show that residents of Isfahan are smoking less than before.
They are also eating deep-fried food less frequently than in other areas of Iran - two times a week instead of three.
Schoolchildren in Isfahan are eating more salty and fatty snacks than they used to, but less than in other parts of the country.
At Harati all boys' elementary school, a handful of students playing ball before class display Healthy Heart badges.
One of them is 10-year-old Mohammad. He has lost 9kg in the past months and now serves as a role model for his schoolmates.
"We must exercise," he says. "We must not smoke cigarettes or eat extra servings of rice. Eat protein and vegetables. I tell the other kids not to eat chips and to eat yoghurt and fruit instead."
Now that the city of Isfahan has shown that healthy habits can be taught in Iran, Nizal Sarrafzadegan and her partners at the Isfahan Provincial Health Centre and the World Health Organization hope to extend their programme nationwide.
They would also like to see their efforts copied in other parts of the Middle East that may be suffering the effects of a Western lifestyle.