New research suggests pounds gained in your 20s may be the most dangerous. A massive study of over 620,000 individuals found that the damage from early weight gain 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. Developing obesity between ages 17 and 29 was linked to a 70% higher risk of early death compared to weight gain later in life. The study, published in the journal eClinicalMedicine, analyzed data from the Obesity and Disease Development Sweden project.
Weight gain later in adulthood, between ages 30 and 60, was also linked to higher death rates, but the connections were generally weaker. Experts explain that people with early obesity onset face a longer exposure to the biological effects of excess weight.
When weight gain occurs in the 20s, blood vessels, the liver, and metabolic systems endure obesity-related strain for decades longer than someone who gains the same weight in their 50s. The study identified type 2 diabetes 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.
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. While type 2 diabetes is the leading risk, early-onset obesity is also tied to higher rates of high blood pressure and specific cancers.
While findings highlight the importance of early obesity prevention strategies, researchers noted other factors come into play and that increases in risk within a population can be difficult to interpret. Further research is needed to understand the effect of early-onset obesity in other populations.