Eating disorders such as anorexia or bulimia are more commonly associated with adolescence or early adulthood.
But a new study, published in the journal BMC Medicine, found one in every 28 women aged 40 to 50 are thought to have an active eating disorder.
The study, which examined more than 5,000 British women, found 15.3% reported having an eating disorder at some point in their lives and 3.6% said they had an eating disorder in the last year.
Less than three in 10 had sought help for their problem.
Dr Nadia Micali, lead author from University College London, said: “Our study shows that eating disorders are not just confined to earlier decades of life, and that both chronic and new onset disorders are apparent in mid-life.
“Many of the women who took part in this study told us this was the first time they had ever spoken about their eating difficulties, so we need to understand why many women did not seek help.
“It may be that there are some barriers women perceive in healthcare access or a lack of awareness among healthcare professionals.”
The study drew data from the Avon Longitudinal Study of Parents and Children. Women who reported having ever had any symptoms of eating disorders, and an equal number of women who reported never having symptoms, were then interviewed.
The researchers found experiencing the death of a carer early in life was associated with a seven fold increased risk of purging disorder.
Parental separation or divorce was linked to increased odds of bulimia nervosa, binge-eating disorder and atypical anorexia nervosa.
Other risk factors for eating disorders included having an unhappy childhood, “low maternal warmth” and sexual abuse in early life.
Dr Micali added: “The early risk factors we assessed were associated with different eating disorders.
“Anorexia, bulimia, binge eating and purging disorder were all associated with childhood unhappiness, and parental separation or divorce during childhood seemed to increase the risk of bulimia, binge eating disorder and atypical anorexia.
“We also found that the death of a carer could increase the likelihood of purging disorder and that sexual abuse during childhood, or a fear of social rejection, was associated with all eating disorders.”