The risk of developing an obesity-related cancer is increasing for millennials in the US, according to a new study.
The "obesity epidemic" over the last 40 years means more people who are carrying excess body-weight could be at risk of developing certain kinds of cancer, according to the paper in the Lancet Public Health journal.
The number of people diagnosed with obesity-related cancers is rising at a faster rate in millennials than in older generations, the study found.
The research, which was funded by the American Cancer Society and the National Cancer Institute, suggests rising levels of obesity-related cancer risks undoing progress made in reducing the number of deaths from the disease.
Ahmedin Jemal, senior author of the study, said: "Although the absolute risk of these cancers is small in younger adults, these findings have important public health implications.
"Given the large increase in the prevalence of overweight and obesity among young people and increasing risks of obesity-related cancers in contemporary birth cohorts, the future burden of these cancers could worsen as younger cohorts age, potentially halting or reversing the progress achieved in reducing cancer mortality over the past several decades.
"Cancer trends in young adults often serve as a sentinel for the future disease burden in older adults, among whom most cancer occurs."
Six of 12 types of obesity-related cancers appeared with a "significantly increased" frequency between 1995 to 2014 in the millions of people included in the study.
Those are multiple myeloma, colorectal, uterine corpus, gallbladder, kidney and pancreatic cancers.
The study found there were steep rises in the number of people in younger generations suffering from the cancers.
The average annual percentage change in pancreatic cancer incidence increased with decreasing age, from 0.77% for those aged between 45 and 49 to 4.34% for those aged between 25 and 29.
The age category that experienced the greatest increase in frequency for four of the other five cancers was also those between 25 to 29.
The age group with the greatest increased risk of developing multiple myeloma was those aged between 30 and 34.
The authors of the study argue that further research is needed to determine what factors are driving the trend.