Led by researchers from Penn State in the USA, the new research found that women who were concerned about their diet felt worse after eating junk food if they were already in a bad mood. However women who were in a good mood experienced no change before or after eating junk food.
"There was little in the way of mood changes right before the unhealthy eating behaviours," said Dr Kristin Heron, who led the study. "However, negative mood was significantly higher after these behaviours."
Professor Joshua Smyth, who co-authored the study added that the team employed a 'unique' research method that evaluated moods and eating behaviours "as they occur in people's daily lives, which can provide a more accurate picture of the relationship between emotions and eating."
The researchers, who presented their findings at the American Psychosomatic Society conference, gathered data from participants in real-life situations by giving handheld computers to 131 women who had high levels of unhealthy eating habits and concerns about their body shape and weight - but did not have eating disorders.
"What we know about mood and eating behaviours comes primarily from studies with eating disorder patients or from laboratory studies," said Heron. "We were interested in studying women in their everyday lives to see whether mood changed before or after they engaged in unhealthy eating and weight control behaviours."
Several times during the day, the devices would prompt the participants to answer questions about their mood and eating behaviours.
"The results from this study can help us to better understand the role mood may play in the development and maintenance of unhealthy eating, and weight-control behaviours, which could be useful for creating more effective treatment programs for people with eating and weight concerns," said Smyth.