Obese women fare poorly as they age

Women who are obese in middle age are more vulnerable to different physical or mental limitations, and are more likely to develop chronic diseases.

There has been a steady rise in the number of elderly persons in industrialised countries and these nations also show a trend of increase in obesity. Very limited data is available regarding the effect of obesity on overall health and wellbeing among those who survive to older ages.

Researchers from Boston studied more than 17,000 women who had been taking part in the ongoing Nurses Health Study and investigated early adulthood and mid-life obesity and weight change from early adulthood to midlife in relation to healthy survival at age 70 and older. These women were on average 50 years old and healthy at the time of start of study in 1976. The researchers looked at various aspects of their lives and lifestyles, including smoking and weight, by sending them questionnaires every 2 years to update the information on incidence of disease and lifestyle and clinical risk factors. 

Of the women who survived until at least age 70 years, 1,686 (10 per cent) met the researchers' criteria for healthy survival while 15 379 (90%) were "usual survivors.". Nearly 60 per cent of the women had cognitive, physical or mental health limitations but no diagnosed major diseases; and 40 per cent had both chronic diseases and cognitive, physical and mental health limitations.

In comparison with stable weight, weight gain since age 18 was significantly associated with reduced odds of healthy survival. It was found that the fatter the women were at 50 years, the more likely they were to have a range of diseases and conditions later in life.

Obese women in middle age were 80 per cent less likely be healthy at age 70 years. For every 1 kg increase of weight gain since age 18, the odds of healthy survival decreased by 5%. The women least likely to end up healthy in old age were already overweight at 18 years and gained =10 kg by age 50 compared to women who stayed lean all their lives.

The above findings provides new evidence that greater adiposity (state of being obese) at mid-life is a strong risk factor predicting a lower probability of healthy survival among older women.  In addition, being both overweight in early adulthood and gaining weight from early adulthood to mid-life independently and significantly reduce the likelihood of healthy survival. The study emphasises the importance of maintaining a healthy weight throughout adulthood as that might be associated with optimal overall health at older ages.