LOS ANGELES (Reuters) - San Francisco has become the first major U.S. city to pass a law that cracks down on the popular practice of giving away free toys with unhealthy restaurant meals for children.

San Francisco’s Board of Supervisors passed the law on Tuesday on a veto-proof 8-to-3 vote. It takes effect on December 1, 2011.

The law, like an ordinance passed earlier this year in nearby Santa Clara County, would require that restaurant kids’ meals meet certain nutritional standards before they could be sold with toys.

Opponents of the law include the National Restaurant Association and McDonald’s Corp, which used its now wildly popular Happy Meal to pioneer the use of free toys to market directly to children.

“We are extremely disappointed with today’s decision. It’s not what our customers want, nor is it something they asked for,” McDonald’s spokeswoman Danya Proud said in a statement.

“Getting a toy with a kid’s meal is just one part of a fun, family experience at McDonald’s,” Proud said.

The San Francisco law would allow toys to be given away with kids’ meals that have less than 600 calories, contain fruits and vegetables, and include beverages without excessive fat or sugar.

Backers of the ordinance say it aims to promote healthy eating habits while combating childhood obesity.

“Our children are sick. Rates of obesity in San Francisco are disturbingly high, especially among children of color,” said San Francisco Supervisor Eric Mar, who sponsored the measure.

“This is a challenge to the restaurant industry to think about children’s health first and join the wide range of local restaurants that have already made this commitment,” Mar said.

HAPPY MEALS IN THE HOT SEAT

Fifteen percent of American children are overweight or obese -- which puts them at risk of developing heart disease, diabetes and cancer, according to the U.S. Centers for Disease Control and Prevention. In some states, the childhood obesity rate is over 30 percent.

The Center for Science in the Public Interest this summer threatened to sue McDonald’s if it did not stop using Happy Meal toys to lure children into its restaurants. A lawyer for that group said it is on track to file the lawsuit in the next several weeks.

McDonald’s debuted the Happy Meal in the United States in 1979 with toys like the “McDoodler” stencil and the “McWrist” wallet. Modern offerings have included themed items from popular films like “Shrek” or sought-after toys like Transformers, Legos or miniature Ty Beanie Babies.

In 2006, the latest year for which data is available, fast-food companies led by McDonald’s spent more than $520 million on advertising and toys to promote meals for children, according to a U.S. Federal Trade Commission report.

When the efforts of other food and beverage companies were included, promotional spending aimed at children topped $1.6 billion.