Adults who pack on pounds between their mid-20s and middle age have an increased risk of premature death – and the same is true of those who lose weight from middle to late adulthood, according to a new study.
The findings suggest that maintaining normal weight throughout adulthood reduces the risk of early death, the China-based researchers said.
Overweight versus obesity
They analysed data from more than 36 000 adults, 40 and older, who were part of a US health survey in 1988–1994 and 1999–2014. Participants' weight and height were checked at the start of the survey, and weight was reported at age 25 and in middle age (average age: 47).
Over an average 12 years, there were 10 500 deaths from any cause. After taking other factors into account, researchers concluded that people who were obese throughout adulthood had the highest risk of early death. Those who were overweight throughout adulthood had a slightly higher risk or none.
Those who gained weight as adults had a higher risk of premature death than those who maintained a normal weight. Weight loss in young to middle adulthood was not significantly related with death risk.
But as people got older, the link between weight gain and death risk weakened, while the association between death risk and weight loss from middle to late adulthood became stronger and significant.
Importance of maintaining normal weight
The study cannot prove cause and effect, and researchers said they can't rule out the possibility that some of the risk was due to factors they didn't investigate.
The findings were published in the BMJ. An Pan, a professor of public health at Huazhong University of Science and Technology in Wuhan, China, led the study.
"Stable obesity across adulthood, weight gain from young to middle adulthood, and weight loss from middle to late adulthood were associated with increased risks of mortality," the researchers said in a journal news release.
"The results highlight the importance of maintaining normal weight across adulthood, especially preventing weight gain in early adulthood, for preventing premature deaths in later life," Pan and his colleagues noted.
In the United States, 36% of men and 38% of women were considered obese in 2016, according to the researchers.
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