Larger women are more likely to suffer from pre-menstrual syndrome, according to a new survey.
Heavier women are more likely to suffer with PMS symptoms
The report, by a researcher from Southampton University, also found that those on the contraceptive pill are less likely to suffer from PMS.
Dr Carrie Sadler claims to have found a link between PMS, a woman's body mass index (BMI) and the use of hormonal contraceptives, such as the pill.
The results come from the Southampton Women's Survey launched in 1998.
It has been carried out by the university together with the Medical Research Council.
Most of the 900 women who took part in the survey reported experiencing problems in the days leading up to their period, with 21% of them suffering with two or more symptoms.
The survey also found that the chances of suffering from the symptoms of PMS were more likely for heavier women with a higher BMI, and less likely for women using the pill or the contraceptive injection.
Dr Sadler said: "Women aged between 16 and 54 make up 28% of the population - they have an essential role in society.
"If up to one in five experience significant pre-menstrual symptoms, this has to be taken seriously."