Women who put on weight as they approach middle age are likely to reduce their chances of enjoying a healthy old age, according to new research.

The study suggests that women who have a high body mass index in middle age (height to weight ratio) are more likely to suffer from major chronic diseases like cancer and coronary heart disease and poor quality of life.

Oscar Franco, clinical professor of public health at Warwick Medical School collaborated with researchers from Harvard School of Public Health in Boston, Massachusetts.

The research team found that for every kilo gained since the age of 18, the odds of healthy survival into old age decreased by five percent.

They also found that women who were overweight at the age of 18 and continued to gain weight as they grew older were most at risk of developing a major chronic disease.

The research team used the Nurses' Health Study, which has gathered data from more than 1,20,000 female registered nurses living in 11 US states since 1976.

Follow-up questionnaires were sent out every two years to update information on disease incidence and lifestyle factors.

Franco said those study participants who had reached the age of 70 and were free of major chronic disease, had no major impairment of cognitive function and no major limitation of physical function were considered examples of 'successful aging.'

The study was published in the Wednesday edition of the British Medical Journal.