Cancers linked to obesity are rising at a faster rate in U.S. millennials than in older generations, a new report shows. The American Cancer Society says the country’s obesity problem risks setting back progress on cancer. The research found that the rates of six out of 12 obesity-related cancers—colorectal, uterine, gallbladder, kidney, pancreatic, and multiple myeloma—all went up, with a steeper rise among millennials. The risk of colorectal, uterine, and gallbladder cancers has doubled for millennials compared to baby boomers, the BBC reports. Researchers say this trend could be because of “younger generations worldwide experiencing an earlier and longer exposure to the dangers of extra weight.” Ahmedin Jemal, of the American Cancer Society, said: “Our findings expose a recent change that could serve as a warning of an increased burden of obesity-related cancers to come in older adults.” However, cancers linked to smoking and infections are declining in younger age groups.