Obesity is never a good thing. It carries a myriad of health risks including increased risk of heart attack, stroke, diabetes and cancer. Those very risks, however, are rising among young people. An analysis done by the American Cancer Society found that obesity related cancers have been increasing in young adults from 1995 to 2014.

“The risk of cancer is increasing in young adults for half of the obesity-related cancers, with the increase steeper in progressively younger ages,” said Vice President of the Surveillance and Health Services Research Program for the American Cancer Society Ahmedin Jemal, who coauthored the study. “The findings from this study are a warning for increased burden of obesity-related cancer in older adults in the future potentially halting or reversing the progress achieved in reducing cancer mortality over the past several decades.”

The obesity related cancers that showed alarming increases among young adults normally developed late in people’s lives. Instead, the millennial age bracket showed worrisome jumps in cancers such as colorectal, endometrial, gallbladder, kidney, pancreatic and multiple myeloma. Multiple myeloma is a form of cancer that develops in bone marrow.

“This study shows the incidence of cancer associated with obesity has been rising dramatically in groups of individuals born in more recent decades,” said Dr. George Chang of MD Anderson Cancer Center.

This is in part due to the fact that millennials are well on their way to being one of the heaviest generations on record. Of the age group, nearly 70 percent are expected to be obese or at least overweight before they reach middle age. The generation behind millennials, often called Gen X, does not look much better. Some studies estimate that over half of all children and teens will be obese by the time they are 35 years old if current trends continue.

How exactly obesity encourages cancer development and growth is still being studied, but the relationship is undeniable.

“We know in animal models that obesity accelerates the onset of cancer,” said Dr. Nathan Berger an oncologist with Case Western Reserve University. “And we know in people that obesity is associated with an increase in cancer and a worse prognosis for patients who have cancer. That’s well established.”

Recovery time is also worse for those who are overweight.

“A patient who is obese will be at higher risk for complications and often times more severe complications from surgery than someone at an optimal weight,” Chang said.

In short, as much as some people sneer at dieting or scoff at those who try and lose a few pounds, keeping your weight under control is not simply a matter of aesthetics. It really could save your life.