Being overweight causes depression and reduces well-being, a new large-scale study has shown. He further indicated that social and physical factors could play a role in the effect.
The results of the study were published in the journal “Human Molecular Genetics”.
With one in four adults estimated to be obese in the UK and a growing number of children affected, obesity is a global health challenge. While the dangers of obesity on physical health are well known, researchers are now discovering that being overweight can also have a significant impact on mental health.
The study sought to determine why a body of evidence now indicates that a higher BMI causes depression. The team used genetic analysis, known as Mendelian randomization, to examine whether the causal link is the result of psychosocial pathways, such as societal influences and social stigma, or physical pathways, such as conditions. metabolic rates linked to a higher BMI. These conditions include high blood pressure, type 2 diabetes, and cardiovascular disease.
In research conducted by the University of Exeter and funded by the Academy of Medical Sciences, the team looked at genetic data from more than 145,000 UK Biobank participants with detailed mental health data available.
In a multifaceted study, researchers analyzed genetic variants linked to higher BMI, as well as the results of a clinically relevant mental health questionnaire designed to assess levels of depression, anxiety and well-being. .
To examine which pathways may be active in depression in people with higher BMIs, the team also interviewed two sets of previously discovered genetic variants.
A set of genes make people bigger, but in better metabolic health, meaning they were less likely to develop conditions related to a higher BMI, like high blood pressure and type 2 diabetes. set of genes analyzed makes people fatter and metabolically unhealthy, or more prone to such conditions.
The team found little difference between the two sets of genetic variants, indicating that physical and social factors play a role in higher rates of depression and lower well-being.
Lead author Jess O’Loughlin, University of Exeter School of Medicine, said: “Obesity and depression are both major global health problems, and our study provides the strongest evidence. stronger to date than a higher BMI causes depression. Understanding whether physical or social factors are responsible for this relationship can help inform effective strategies for improving mental health and well-being. “
O’Loughlin added, “Our research suggests that being fatter carries a higher risk of depression, regardless of the role of metabolic health. This suggests that physical health and social factors, such as social stigma, both play a role in the relationship between obesity and depression. “
Lead author Dr Francesco Casanova, University of Exeter School of Medicine, said: “This is a solid study, made possible by the quality of the UK Biobank data. Our research adds to a body of evidence that being overweight causes depression. helping people lose weight could benefit both their mental and physical health. “