From fears that eating chicken wings makes it hard to find a husband to beliefs that pineapple jeopardises fertility, a host of food taboos are fuelling malnutrition among Indonesian girls, experts said as they launched an adolescent health drive.
Nutritionists said girls ate very little protein, vegetables or fruit, preferring to fill up with rice and processed snacks which were often sweet or fried.
"Indonesian girls are being left behind when it comes to nutrition," said Kecia Bertermann of Girl Effect, a non-profit that uses mobile technology to empower girls.
"They don't understand why their health is important, nor how nutrition is connected to doing well at school, at work or for their futures."
The U.N. children's agency UNICEF says Indonesia has some of the world's most troubling nutrition statistics. Two in five adolescent girls are thin due to undernutrition, which is a particular concern given many girls begin childbearing in their teens.
Experts said the food taboos were part of a wider system of cultural and social habits leading to poor adolescent nutrition, which could impact girls' education and opportunities.
One myth is that cucumber stimulates excessive vaginal discharge, another that eating pineapple can prevent girls from conceiving later on or cause miscarriages in pregnant women.
Others believe spicy food can cause appendicitis and make breast milk spicy, oily foods can cause sore throats and peanuts can cause acne, while chicken feet – like chicken wings – can cause girls to struggle finding a husband.
Research by Girl Effect found urban girls ate little or no breakfast, snacked on "empty foods" throughout the day and thought feeling full was the same as being well nourished. Snacks tended to be carbohydrate-heavy, leaving girls short of protein, vitamins and minerals.
Girl Effect is teaming up with global organisation Nutrition International to improve girls' eating habits via its Springster mobile app, a platform providing interactive content for girls on health and social issues. If successful, the initiative could be expanded to the Philippines and Nigeria.
Experts said Indonesia was a country with "a double burden of malnutrition" with some people stunted and others overweight but also lacking micronutrients.
Marion Roche, a specialist in adolescent health at Nutrition International, said the poor nutritional knowledge among girls was particularly striking given infant nutrition had improved in Indonesia.
"Adolescent girls don't know what healthy looks like, as health is understood as the absence of illness," she said. "We need to give them the knowledge to make healthy choices."