MOST women have an unhealthy "apple figure", putting them at risk of infertility, cancer and heart disease, a health charity has warned.
The average woman's waist measures 5cm more than the recommendation of 80cm or less. This puts the majority in the "high health risk" category, according to research.
The average waist-to-hip ratio has also increased, indicating that an apple body shape has become more common than the healthier "pear".
Research suggests that excess weight around the waist increases the chances of breast cancer, heart disease and Type 2 diabetes.
It has also been linked to the disruption of ovarian function, which has consequences for fertility.
A survey of 54,000 people by Nuffield Health found that more than half of women had a body mass index (BMI) that exceeded the healthy 18-25 range. More than 16pc were classed as moderately or morbidly obese.
The findings raise health concerns over the average waist size of women.
Dr Davina Deniszczyc, professional head of physicians and diagnostics at Nuffield Health, said: "Whilst waist size may seem like a cosmetic issue, this is not about women fitting into their skinny jeans, rather it is an important indicator of overall health and well-being, particularly when taken into account with other health measurements.
"Experts are increasingly finding central (or abdominal) obesity, measured through waist size, to be a better indicator of obesity than BMI.
"The results for women highlight a worrying problem as fat being stored around the waist can contribute to significant health issues, such as breast cancer and infertility."
Of the women who were measured in the study, half were aged between 26 and 46.
The research also showed that many people suffer from a lack of sleep, with people getting an average of seven hours a night.
Studies have recommended that adults have seven to nine hours.
The Health MOT measures BMI, heart rate, cholesterol, aerobic fitness, blood pressure and sugar levels.
Dr Deniszczyc said: "Our Health MOT results provide a fascinating snapshot of some health issues.
"Being part of the Health MOT programme is proven to help you lose weight, move your BMI into the healthy weight category, and get your blood pressure to a healthy level."
Chris Jones, head of physiology at Nuffield Health, said women concerned about their waistline should check their waist size every few weeks to ensure it is getting smaller.
He added: "Some foods and drinks cause blood sugar levels to change too often and can increase our fat store around the stomach.
"Make sure you exercise for at least two-and-a-half hours per week and try to walk as much as possible. If you are concerned about your waist size, visit your GP."