A new study published in the International Journal of Obesity found that Middle-aged women who suffer from sleep disorders are more likely to have problems with their weight than their peers who get the recommended eight hours a night. Although there are studies that have established the link between weight gain and sleep, these findings suggest that sleep problems preceded weight gain in the subjects. The researchers at the University of Helsinki looked into the sleeping habits and weights of around 7,300 adults aged between 40 and 60 over a seven-year period and found that around one in three of the 5,700 women participating in the study with frequent sleep problems gained at least 11 pounds in weight over the course of the study. In comparison, just one in five of those women who slept well through the night gained as much weight. Lead researcher Peppi Lyytikainen told Reuters Health that this correlation could be down to the fact that sleep disorders could affect the chemicals that dictate appetite. The link in the women persisted even when the investigators accounted for a number of factors that can affect both sleep quality and weight gain -- including participants' body weight at the study's start, their exercise habits and their general physical and mental health. The study concluded that sleep problems likely contribute to weight gain which means that sleep problems need to be taken into account when trying to prevent and manage weight gain and obesity.