Men are also nowhere behind the fairer sex, for the research found that the average man's waistline has grown by 1.4 inches to 38 inches.
"We know high body weight increases the risk of a number of cancers and it is important we get this message out to as many people as possible," the Daily Mail quoted Dr Lesley Walker, of Cancer Research UK, as saying.
"A healthy diet with plenty of fibre, fruit and vegetables, as well as regular exercise can help people lose weight and reduce their risk of cancer," he added.
The trend was found to be dominant in the under 45s, where the proportion of men with a body mass index over 35, and of women with a BMI of over 40, has grown two-fold during the decade.
Lead researcher Professor Jane Wardle said it is possible that young people follow a less healthy lifestyle than their elders.
"Snacking habits, takeaway meals high in fat and sedentary lifestyles where many people spend both work and leisure time sitting in front of a computer are all likely to contribute to the results."
She added that genetics also playa vital role in the growing rate of obesity.
The study will be published in International Journal of Obesity.