London, Sept 30 : Being overweight in midlife might give rise to multiple chronic diseases, impair cognitive function and physical function and mental health in women in older age, says a new study.

The researchers showed that women who were lean at age 18 and maintained a healthy weight through mid-life had the best odds of achieving optimal health later in life.

"Since body weight is a modifiable factor, the good news is that healthy aging is not purely the consequence of good genes or other factors that one cannot change," the British Medical Journal quoted Qi Sun, a researcher in the HSPH Department of Nutrition as saying.

"If women maintain a healthy weight as adults, they may increase their odds of enjoying a healthy life in their later years," Sun added.

Lead researcher Sun and senior author Francine Grodstein, associate professor in the Department of Epidemiology at HSPH and in the Department of Medicine at BWH, analyzed data of 17,065 female participants who had survived until at least age 70.

The results showed that 1,686 women who lived until at least age 70 reported being free of major chronic diseases, had good cognitive and physical functions and had good mental health.

These women were defined as "healthy survivors."

The remaining 15,379 women who lived until at least age 70 were defined as "usual survivors."

Among these women, 3.3pct had chronic diseases but no other health limitations; 59.5pct had cognitive, physical or mental health limitations but no diagnosed major diseases; and 37.1pct suffered from both chronic diseases and cognitive, physical and mental health limitations.

The study also showed that obese women had 79pct lower odds of healthy survival compared with lean women.

The researchers also found that women who were overweight (BMI greater than or equal to 25) at age 18 and gained more than 22 pounds between age 18 and 50 had the worst odds of healthy survival.

"An important aspect of this study is the broad focus on many aspects of health, and not just on whether people get a single disease," said Grodstein.

"Our finding that being overweight at mid-life affects so many aspects of health simultaneously really emphasizes the harms of being overweight," Grodstein added.