Expanding waistlines and stress are the main reasons behind the surge, which scientists say particularly affects women between the ages of 45 and 54.
They found high blood pressure – which is linked to stress and is the biggest cause of strokes – rises dramatically in women aged 35 to 44.
In the decade after that, women are 2.4 times more likely than men to have a stroke, according to the report published in the online edition of the Neurology journal.
Strokes – caused by a clot or bleeding in the brain – kill an estimated 67,000 a year.
They are also the biggest cause of severe disability, with more than 250,000 living with serious impairment as a result.
The study, which was led by Dr Amytis Towfighi, of the Stroke Centre and Department of Neurology, at the University of California, Los Angeles, monitored 17,000 women and men over six years.
While there was a marked increase in the number of women having strokes between the ages of 45 and 54, there was no difference in the stroke rates between men and women in the 35 to 44 and 55 to 64 age brackets.
The team also discovered that men aged between 55 and 64 are three times more likely to have a stroke than men aged 45 to 54, although the reasons for this are not clear.
But the researchers also noted that obesity in middle-aged women was not always caused by poor diet.
"It has been suggested that women nearing menopause are particularly susceptible to steep increases in waist circumference," the report said.
Reduced estrogen production and use of hormone replacement therapy in addition to weight gain have been linked to strokes, it added.
Joe Korner, of the Stroke Association, said: "Our obesity problem is not as big as in the U.S., but it is growing.
"Forty per cent of the 150,000 strokes in the UK every year would be prevented if we could get people to control their blood pressure."