Obesity linked to higher cancer risk in young Korean adults
Ten-year cancer incidence was 1.84% at normal weight, 2.24% with class I obesity and 2.62% with class II obesity.
Edited by Boris Djordjevic · AgingResearch.News
An observational cohort study followed 6,313,338 Korean adults aged 20 to 39 without prior cancer who participated in national health screening. Researchers grouped participants by body mass index, a measure of weight relative to height, using Asian-specific cutoffs. During an average follow-up of 11.2 years, 151,893 cancer cases occurred.
Ten-year cancer incidence was 1.84% in the normal-weight group, 2.24% in class I obesity and 2.62% in class II obesity, the higher obesity category. Obesity was associated with higher early-onset cancer risk that persisted into midlife, with patterns varying by cancer type. It was not associated with higher risk of breast cancer diagnosed by age 50.
Why it matters
The study bears on whether weight management early in adulthood may matter for cancer prevention into midlife. The authors suggested early weight management may be important for prevention.
Caveats
This observational study cannot establish cause and effect, and unmeasured factors, including smoking burden, may have influenced the associations. The sample was limited to screening participants and was not representative of the wider population.
The paper
Obesity and Cancer Risk in Young Adults in Korea : A Nationwide Health Screening Cohort Study
St. Vincent's Hospital; Bucheon St. Mary's Hospital
Annals of Internal Medicine, Oct 27, 2026
