BPA (bisphenol A) is a man-made compound that is used to make certain plastics and is found in food packaging, sporting equipment, water bottles, and in the lining of water pipes. It has some hormone-like properties, which has made its safety questionable. In 2010, the FDA warned that BPA may be hazardous to fetuses, infants, and young children, and in 2012, the US banned BPA use in baby bottles and sippy cups. However, it is not banned from other food containers. Some studies show that 92% of Americans have detectable BPA levels in their bodies.
A recent study in PLoS One showed that preteen girls, aged 9-12, who had higher than average levels of BPA in their urine, were 2x as likely to be obese. A second study published in the Journal of the American Medical Association in 2012 found a similar result. They reported that higher BPA levels in boys and girls were correlated to higher levels of obesity compared to those children with lower levels of BPA, even after taking calories and exercise into account. An unhealthy diet and lack of exercise are still the leading causes of obesity; however, it is important to note that other environmental factors may be contributing to the obesity epidemic.