Boys with excess belly fat enter puberty at an earlier age than average, scientists have found, a recent study suggests. According to data collected from 527 Chilean boys aged 4 to 7 years, both total body obesity and central obesity, or excess belly fat, were associated with greater odds of starting puberty before age 9, researchers from the University of Chile in Santiago, Chile reported. "With the increase in childhood obesity worldwide, there has been an advance in the age at which puberty begins in girls. However, in boys the evidence has been controversial," said Maria Veronica Mericq, lead author of the study. Some U.S. studies have found that obesity delayed puberty, whereas another study showed that only overweight but not obesity-induced earlier puberty in boys. In contrast, study results from Europe showed earlier puberty in boys with overweight and obesity. Early puberty--called precocious puberty--is linked to possible problems including stunted growth and emotional-social problems, according to the Hormone Health Network.