Obese adults who do not cut to a healthy body weight by middle age increase their risk of dying prematurely by more than a fifth, a study has warned.
Scientists from Huazhong University in China found that gaining weight between the ages of 25 and 47 increases the chances of an early death from any cause by 22%.
Continuing to pile on the pounds past the age of 40 raises the likelihood of dying prematurely even further.
Dr Chen Chen and his co-authors also found that people who drop from an obese to a healthy body mass index (BMI) after hitting middle age still have a 30% higher chance of early death.
The study, published in the British Medical Journal (BMJ), analysed data for 36,051 US citizens who were 40 or over.
As well as a higher risk of early death from any cause, people who became obese between 25 and middle adulthood had a 49% increased risk of death from heart disease.
Overall, being obese during the entirety of adult life carried the biggest risks, with up to a 72% increased danger of dying young.
People who lost weight and went from being obese to a healthy weight over the same period had no increased risk.
“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 authors wrote. “The findings imply that maintaining normal weight across adulthood, especially preventing weight gain in early adulthood, is important for preventing premature deaths in later life.”
Katharine Jenner, nutritionist and campaign director at Action on Sugar, told the Daily Mail that the findings demonstrate the importance of preventing obesity in the first place, not just treating the diseases it causes.