Success may no longer be measured by the size of your house, car or bank balance – it could come down to your waistline.

Obese men make more money than their slimmer counterparts, according to new research from the University of Otago's Christchurch Health and Development Study (CHDS).

The opposite can be said for women, with obese or overweight women earning less than women of average weight.

They were also more likely to be depressed and dissatisfied with their lives, while an obese man's mental health was generally unaffected by his girth.

The study analysed the relationship between a person's size, using their Body Mass Index (BMI), and financial aspects of their lives such as net weekly income, savings, household income. They also examined depression levels and life satisfaction.

On average, men with a BMI of more than 30 – the classification for obesity – earn $140 a week more than men with a normal BMI. Obese women earn $60 less than a woman with a "normal" BMI rating.

It is the first study to be released under the leadership of new CHDS director Associate Professor John Horwood since Professor David Fergusson retired.

The study has followed the lives of more than 1200 Canterbury children in intimate detail for 38 years.

It has spawned more than 440 scientific papers, reports, books, prompted major policy changes and been cited more than 22,000 times.

Horwood said the group embarked on its latest project after international research suggested a possible link between obesity and poorer mental health and wellbeing.

They decided to examine the CHDS cohort at age 30 and 35 to try and identify a link in New Zealanders.

The study found being overweight or obese was associated with poorer outcomes, but only in women, Horwood said.

"There was a clear relationship between larger men and larger weekly pay packets. But for men, being classified as overweight or obese according to the BMI Index did not negatively affect other outcomes measured in the study such as self-esteem or mental health," he said.

Horwood said the study was designed to "establish relationships between size and psychosocial outcomes", rather than explain them.

There was likely to be a range of reasons behind the findings, he said, particularly in those related to women.

"One reason could be Western society's general view that female obesity is undesirable and unattractive. Another could be growing evidence to suggest women are more responsive to adversity in life than men," he said.

"Not only is there more stigma attached to weight and body composition for women but they may also be more likely to perceive being overweight or obese as a source of stress or adversity."

Horwood hoped to continue the study when the CHDS cohort was older, to see if the link persisted over time.