Australian researchers have found the strongest evidence so far that obesity is linked to depression.
A new study published on Tuesday by the University of South Australia (UniSA) and University of Exeter in the United Kingdom (UK) revealed that the mental impact of being obese can cause depression.
Researchers from the institution analyzed the records of 48,000 UK patients with depression and compared them to the records of a control group of 290,000 people.
Elina Hypponen, the study's lead author in UniSA, said that her team took a genomic approach to the study.
"We separated the psychological component of obesity from the impact of obesity-related health problems using genes associated with higher body mass index (BMI), but with lower risk of diseases like diabetes," Elina said in a statement on Tuesday.
"These genes were just as strongly associated with depression as those genes associated with higher BMI and diabetes. This suggests that being overweight causes depression both with and without related health issues, particularly in women," she said.
"The current global obesity epidemic is very concerning. Our research shows that being overweight doesn't just increase the risks of chronic diseases such as cancer and cardiovascular disease; it can also lead to depression," she added.
A person is considered obese if they are more than 20 percent over their ideal weight. According to the Australian Institute of Health and Welfare (AIHW), almost two-thirds of Australians were either overweight or obese in 2014-15.
Surprisingly, the researchers found that very thin men were more likely to suffer from depression than very thin women or men of a healthy weight.