Yet, even in this neighborhood, Qatar stands out.

According to the International Association for the Study of Obesity, Qatar ranks sixth globally for prevalence of obesity and has the highest rate of obesity among boys in the Middle East and North African region. A recent article in the Qatari newspaper Al Watan said that local health experts predicted that within five years, 73 percent of Qatari women and 69 percent of the men would qualify as obese.

Obesity is considered the most important factor in the development of diabetes and is a prime contributor to many other ailments, like hypertension. The International Diabetes Federation ranks Qatar fifth globally in terms of the proportion of people aged 20 to 79 with diabetes.

The March of Dimes Foundation, a United States charity that focuses on trying to wipe out birth defects, listed Qatar as 16th globally for the incidence of birth defects per 1,000 live births. The chief cause of the problem in Qatar is consanguineous marriages, experts here said. Saudi Arabia ranked second globally.

Image Young boys watched others taking to the desert in S.U.V.'s on the outskirts of Doha. Walking is not popular in Qatar's humidity and intense heat. Credit... Shawn Baldwin for The New York Times

For all of these challenges, and for all of its wealth, Qatar has primarily focused on the treatment of diseases rather than on prevention.

Everyone here points to lifestyle and tradition to explain the nation’s health crises. While it was once taboo to talk about the problems involved with marrying relatives, they are now talked about openly. There have been some discussions about premarital genetic screening, or genetic testing done at birth. But the tradition is so strong, no one has raised the prospect of curbing it.

“You can’t tackle the issue,” said Moza al-Malki, a family therapist and writer. “There are some big families, clans, they don’t marry outside the family. They won’t allow it.”