The more weight women gain from the age of 18 until middle age, the less likely they are to enjoy a long and healthy life, according to new research published on bmj.com today.
Compared with lean women, the results show that being obese in middle age reduces those odds by 79%, underscoring the importance of maintaining a healthy weight from early adulthood, say the authors.
Despite the evidence that overweight and obesity can significantly increase the risk of early death, little is known about how adiposity affects overall health and wellbeing among those who survive to older ages.
To address this issue, researchers in the United States investigated the theory that being overweight in mid life is associated with a reduced probability of maintaining optimal health among those who survive to older ages.
Their findings are based on comprehensive two yearly monitoring of more than 17,000 middle-aged women in the United States as part of the Nurses Health Study.
Healthy survival referred to participants who survived to age 70 years or older, were free of major chronic diseases, and had good cognitive, physical and mental health. Usual survival referred to participants who survived to age 70 years or older but did not meet these criteria.
After adjusting for several factors, increased body mass index at the start of the study was significantly associated with reduced odds of healthy survival. Every one unit increase of body mass index was associated with a 12% reduction in the odds of healthy survival.
Similarly, in comparison to women of stable weight, weight gain since the age of 18 was significantly associated with reduced odds of healthy survival. For every one kilogram increase of weight gain since age 18 years, the odds of healthy survival decreased by 5%.
The worst odds of healthy survival were found among women who were overweight at 18 and gained 10kg or more by middle age.
But even among women who were lean at 18, relative to those who kept a stable weight, women who gained more than 10kg by middle age were 59% less likely to achieve healthy survival.
These data provide evidence that adiposity in mid life is strongly related to a reduced probability of healthy survival among women who live to older ages, and stress the importance of maintaining a healthy weight from early adulthood, say the authors.
"Given that more and more Americans are surviving to older ages and, at the same time, gaining weight, our results may be particularly important with respect to clinical or public health policies and deserve further investigation and confirmation in additional studies," they conclude.