Forty percent of cancer cases in the U.S. are the types of tumors with a link to obesity, according to new Centers for Disease Control and Prevention statistical research.

Some 631,000 people in America were diagnosed in 2014 with a cancer associated with excess body weight by previous research from the International Agency for Research on Cancer, the CDC reports today. The numbers of some kinds of tumors, and the cancer rates in some areas, are increasing, the agency added.

“The burden of overweight- and obesity-related cancer is high in the United States,” report the CDC doctors. “Incidence rates of overweight- and obesity-related cancers except colorectal cancer have increased in some age groups and states.

“There is consistent evidence that a high BMI is associated with cancer risk,” they add.

The cancers are: adenocarcinoma of the esophagus, breast cancers in post-menopause women, colon and rectal cancers, endometrium, gallbladder, gastric cardia, kidney, liver, ovary, pancreas, thyroid, meningioma, and multiple myeloma.

The data were taken from the United States Cancer Statistics for 2014, and spanned the years 2005 to 2014.

The incidence of all the kinds of obesity-related cancers increased significantly over the course of the decade (except colorectal cancer), for the age group 20 to 74.

The increase and incidence of the obesity-related cancers were driven by females (the rate of these cancers was 218.1 per 100,000 people, compared to 115 per 100,000 for males). However, that was likely because nearly half of all the female cases (42 percent) were endometrial, ovarian or postmenopause breast cancers, the authors add.

But there were limitations, the CDC doctors report. Primarily, none of the cases were evaluated for their relation to the patients’ weights. In fact, the weights and BMI histories of the cancer patients were not known. Only the cancers identified by the IARC were categorized in the data – and the role of weight gain in other kinds of cancers has yet to be understood.

“Finally, although this report tracks overweigh- and obesity-related cancers, it does not estimate what proportion of these cancers are attributable to overweight and obesity,” they conclude.

The risk factors of cancer continue to be debated. Last year, health officials in the United Kingdom announced that any intake of alcohol increases cancer risks. But at the same time, the statistical methodology of how to categorize cancer increases and risks has been at debate, as shown especially in last year’s debate over whether metastatic prostate rates were indeed “skyrocketing.”