Fat kids everywhere, rejoice! There's no link between childhood obesity and junk food sold in schools, a new study has found.

Cities all over the country have been busy banning the sale of sweet and salty snacks in public schools in a bid to fight childhood obesity (thanks, Mrs. Obama). But a new study by researchers at Pennsylvania State University suggests that the strategy may be ineffective, The New York Times reports. The research appears in the January issue of the journal Sociology of Education.

Researchers tracked the body mass indexes of 19,450 students from fifth through eighth grade. They found that 59 percent of fifth-graders attended a school where candy bars, chips and/or soft drinks — so called “competitive foods” — were sold. That number had risen to 86 percent by eighth grade.

Scientists compared children's weight in schools where junk food was sold and in schools where it was banned. They also evaluated eighth-graders who moved into schools that sold junk food with those who did not, and children who never attended a school that sold unhealthy snacks with those who did. Finally, they compared children who always attended schools with snacks with those who moved out of such schools.

No matter how they sliced the data, they could find no correlation at all between obesity and attending a school where candy and junk food were sold. The study also found that “the relationship between competitive foods and weight gain did not vary significantly by gender, race/ethnicity or family socioeconomic status.”

However, “the relationship between consumption of sugar-sweetened drinks and snacks and childhood obesity is well established,” the authors wrote. So what's the deal? The researchers speculate that food preferences and eating habits are established early in life, before adolescence, and not greatly influenced by environmental options later. So kids who gorge on Doritos and Snickers bars are gonna do it whether it's at home, at school or at the corner 7-11, and kids who aren't interested will not be tempted if such fare is available at school. Who these mutant children are who are not interested in candy, chips and soda is another story.

Follow Samantha Bonar @samanthabonar.

LA Weekly