Putting on excess weight before the age of 30 could dramatically raise the risk of dying early, a major study suggests.
Researchers tracking more than 600,000 people found those who developed obesity in early adulthood were significantly more likely to die prematurely than those who did not become obese until later in life, or avoided it altogether.
The study, led by scientists at Lund University and published in eClinicalMedicine, found that being obese between the ages of 17 and 29 was linked to a roughly 70 per cent higher risk of early death.
Experts say the findings suggest that the time of weight gain may be just as important as the amount of weight gained.
The researchers analysed weight changes in participants between the ages of 17 and 60 using repeated clinical measurements rather than self-reported data, allowing them to track long-term patterns more reliably than many previous studies.
On average, participants gained around 0.4kg per year, but those whose weight increased more rapidly over time were more likely to die from diseases linked to obesity, including heart disease.
According to lead researcher Tanja Stocks, the timing of weight gain appears to play a key role.
‘The most consistent finding is that weight gain at a younger age is linked to a higher risk of premature death,’ she said.
Having excess weight before the age of 30 could raise the risk of dying early, a study suggests
In adults, being overweight or obese is associated with a number of life-limiting conditions, such as type 2 diabetes, cardiovascular disease and at least 13 types of cancer.
Obesity also leads to increased mortality from all causes and severe outcomes for conditions like COVID-19.
One possible explanation is that people who develop obesity earlier are exposed to the biological effects of excess weight for a longer period.
However, the pattern was not the same across all conditions.
For women, the risk of cancer appeared to be similar regardless of when weight gain occurred, suggesting other biological mechanisms may also be involved.
Another of the paper’s authors, Dr Huyen Le, said hormonal changes, such as those linked to menopause, could be one possible factor.
The researchers stressed the findings reflect overall patterns rather than precise individual risk.
A 70 per cent increase does not mean that most people will die early, but instead indicates a higher risk at a population level.
They say the results add to growing evidence of an ‘obesogenic society’ that encourages weight gain and underline the importance of preventing obesity earlier in life.
