Weight management is often treated as a "middle-age" problem, but new research suggests that the pounds you pack on in your 20s may be the most dangerous of your life.
A massive study of more than 620,000 individuals found that the damage from is disproportionately high and surprisingly permanent. According to the findings, the younger someone is when obesity sets in, the higher the risk of early mortality.
The study, published in the journal eClinicalMedicine, analyzed data from the Obesity and Disease Development Sweden project.
"The most consistent finding is that weight gain at a younger age is linked to a higher risk of premature death later in life, compared with people who gain less weight," Tanja Stocks, a professor at Lund University and one of the researchers behind the study, said in a press release.
Developing obesity between the ages of 17 and 29 was linked to a 70% higher risk of early death compared to later in life.
Weight gain later in adulthood, between ages 30 and 60, was also linked to higher death rates, but the connections were generally weaker.
"One possible explanation for why people with early obesity onset are at greater risk is their longer period exposed to the biological effects of excess weight," Huyen Le, a doctoral student at Lund University and first author of the study, said in the release.
When weight gain happens in the 20s, the blood vessels, liver and endure obesity-related strain for decades longer than someone who gains the same weight in their 50s, experts say.
The study identified as the leading cause of death associated with early-onset obesity. Other significant risks included high blood pressure, liver cancer in men and uterine cancer in women.
To reach these conclusions, researchers tracked participants’ weight paths across adulthood over more than 50 years, focusing on three specific windows: ages 17 to 29, 30 to 44, and 45 to 60.
Using a body mass index (BMI) of 30 or higher to define obesity, the team compared weight data against Sweden’s national death registry.
After adjusting for a variety of factors, including and marital status, the trend showed that becoming obese later in life still carried risks, but the danger compounded the longer people stayed obese.
While these findings highlight the "importance of early and sustained obesity ," the researchers noted that other factors come into play, and that increases in risk within a population can be difficult to interpret.
"We shouldn’t get too hung up on exact risk figures," Stocks said.
"They are rarely entirely accurate, as they are influenced, for example, by the factors taken into account and the accuracy with which both risk factors and outcomes have been measured."
Because the study was conducted in Sweden, more research is needed to understand the effect of early-onset obesity in other populations, the team noted.