Image of fat rat / Shutterstock

Researchers say that the obesity crisis sweeping across the United States is not restricted to humans. A new study by Pro Publica found that animals are also putting on the pounds – both domesticated animals and urban wildlife such as city rats and pigeons. This has lead the study’s authors to widen their search for the cause of obesity to include factors other than overeating, such as chemicals present in our water, soil and air.

green design, eco design, sustainable design, obesity, hormone disrupters, Pro Publica, Stirling University, obesity crisis, obesity factors, obese animalsImage ©vmiramontes

Like humans, domesticated animals across the country have been getting heavier, but overeating and insufficient exercise may not be the sole cause for this weight gain. Lab animals that live near animals are also getting plumper, according to the report.

Related: Study Finds Sugar Loaded Drinks Responsible for 180,000 Deaths Worldwide

Surprisingly, animals beyond human care are also showing unusual weight gain, including a group of feral rats in Baltimore. Scientists at Stirling University are looking to chemicals that affect metabolism as the culprits. Although still in the early stages, the study points to chemicals in insecticides that renders lab mice less active, such that they are less likely to exercise and burn off calories. Other chemicals like BVO, which is present in soda drinks in the U.S. (but banned in Europe), is also suspected of affecting the hormone systems.

Another study has linked obesity with plastics and food packaging, materials that may also contribute to teen diabetes. Although at this point the studies are in their infancy, they raise important issues about the chemicals in our food and environment and how they affect both animal and human health.

Via USA Today

Related: Michael Moss Investigates How Junk Food is Engineered to be Addictive