The study found that weight loss during middle age or later in life is "significantly related to increased mortality risk".
Those who remained overweight during their adult lives without becoming obese showed no correlation to an increase in risk of premature death.
Those who remained obese throughout adulthood showed the highest risk of premature death.
"Our takeaway is that it's best to prevent weight gain at younger ages to reduce the risk of premature death later in life," says An Pan, study author via CNN.
Study authors pointed out that their work did not differentiate between intentional or unintentional weight loss later in life.
"Unintentional weight loss could be a sign of underlying conditions like diabetes or cancer ... the first message is to try not to gain weight when you're young, and in an old age focus on maintaining a healthy lifestyle. Weight is a secondary consideration," says An.
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