University of Adelaide research has found that people are more likely to lose weight if they focus on being happy, rather than dieting.

Many people believe weight loss is the key to happiness but one Adelaide university researcher has found it may work the other way around.

A study of obese patients has shown that people are more likely to lose weight if they focus on being happy, rather than dieting, University of Adelaide psychologist Sharon Robertson says.

She also says obese people have lower levels of emotional wellbeing, which helps prevent weight loss.

"There's no joy in focusing on weight loss, particularly if someone is constantly failing to lose weight," Ms Robertson said on Wednesday.

"Positive psychology techniques promote positive thinking and positive feelings, and this feel-good effect may lead to an increase in motivation ... it can promote weight loss behaviour.

Ms Robertson said her research did not mean that traditional weight-loss programs were ineffective.

"But for those who have had little success with weight loss, perhaps focusing on their psychological health first will lead to better outcomes," she said.