Dubai has some of the heaviest citizens in the world, and last year found a pretty effective way to motivate them to lose weight: gold.

This summer, the emirate is at it again, and this time it wants to also give gold to children who shed pounds. But some health professionals are worried the program might lead to crash dieting and other health problems for kids.

The emirate's weight-loss program, called "Your Child in Gold," gives everyone one gram of gold for every kilogram (2.2 pounds) of reduced weight. A gram is worth just under $42.

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Dubai is awarding twice as much gold -- two grams per person for every lost kilogram -- to families who participate with a child between ages 2 and 14.

You'd think children might be more motivated by offers of video games or trips to Dubai's Wild Wadi water park. But officials know the real key to family weight loss is getting the parents on board, and offering more gold is one way to get mom and dad's attention.

Dubai belongs to the United Arab Emirates, the sixth-heaviest country in the world, Quartz reports, citing a 2012 survey published in BMC Public Health Journal. (The U.S. ranked first in the survey.) Dubai is also a key hub for the gold trade, handling about 40 percent of the world's physical bullion exchange last year.

On the first day of the program's launch this month, about 15 percent of the 9,200 enrollees registered as families. Participants must visit weigh-in sites run by health professionals to measure their progress, and the final weigh-in is Sept. 15.

Some experts have already begun telling families to take it easy with children's weight loss. One Dubai nutritionist has warned parents not to push their kids too hard and to keep them away from the gym, according to the 7 Days in Dubai website.

Local doctors were also cautious about the impact of the program on children. "If a child is dramatically overweight, then two [kilograms] over the course of a month is fine," a family medicine doctor told The National. "But if the child is under four and they're losing that much weight, that might pose some health concerns."

The head of Dubai Municipality said the program was needed because many schools in the region have cut exercise classes. "Kids are staying in front of the TV and on the computers," said Hussain Nasser Lootah, according to 7 Days in Dubai. "There is no exercising in schools."