London-Being overweight during childhood triples the risk of developing depression in later life, according to new research.
People who are overweight at the age of eight or 13 are more at risk of depression than those who suffer weight problems in middle age, the study found.
Carrying excess weight throughout your life quadruples your chances of developing the mental health disorder, the research adds.
The researchers suggest that childhood obesity may permanently damage self-esteem, resulting in depression later on.
One in three children in the US and UK are overweight or obese, previous research has shown.
Study participants were assessed to determine whether they had symptoms of depression or if they had previously been diagnosed with the condition.
The researchers then looked at school records dating back almost seven decades to find out if the participants were overweight as children, defined as having a BMI between 25 and 29.9.
Data revealing their weight at the age of 50 was gathered from a previous study with the same participants in Reykjavik.
Results revealed that carrying excess weight in childhood is a stronger predictor of depression later down the line than being overweight in middle age.
The findings showed being overweight at the age of eight or 13 more than triples the risk, while carrying excess weight throughout your life quadruples your chances of the mental health disorder.
Previous studies have shown that people who are obese are more likely to become depressed, but few have looked at the long-term influence of childhood obesity.
The scientists, who presented their findings at this year's European Congress on Obesity, said: 'Our findings suggest that some of the underlying mechanisms linking overweight or obesity to depression stem from childhood.
Scientists believe being overweight as a child may permanently damage self-esteem (stock).
'A shared genetic risk or low self-esteem, which is frequently associated with those who do not conform to the ideal body type, could be responsible.
'Given the rise in adolescents' obesity and greater influence of social media on body image, understanding the associations between childhood obesity and depression is critical.'
This comes after researchers from the University of Navarra in Spain found eating one or two meat-free meals a week halves the risk of becoming obese.
The so-called flexitarian lifestyle also encourages people to eat more fruit and vegetables, they found.