BANGKOK — An apple a day kept the doctor away — but now in Asia, a cup of milk might do the trick.

Milk and other dairy products have become an unexpected ally in the fight against Asia’s newest dietary challenges: obesity, and vitamin and mineral deficiencies, according to a report by the U.N. Food and Agriculture Organization that was released today.

“This report is an eye-opener and a wake-up call ... we still have nearly half-a-billion hungry people in this region,” said Kundhavi Kadiresan, FAO’s assistant director general.

But “increased consumption of milk and dairy holds out excellent promise to improve nutrition,” she said.