Women looking for some extra motivation to lose weight might consider this: A new study shows the longer those pounds stay on, the higher the risk for breast, endometrial, colon and kidney cancers.

Odds of getting cancer increased by 10 percent for every 10 years a woman was obese, and they climbed by 7 percent for every decade she’d been overweight, according to the study of 74,000 women, published in the online journal PLOS Medicine.

The study noted that seven out of 10 adults in the U.S. are overweight, and more than a third are considered obese. Experts say excess weight is a factor in 20 percent of all cancer deaths, though the precise impact can be difficult to pinpoint because of other factors such as smoking, a sedentary lifestyle and Type 2 diabetes. But this study accounted for some of those risk factors and still found the excess cancer risk.

Why is weight connected with cancer? One reason is that excess fat affects hormones such as estrogen that may be the contributors to breast and endometrial cancers. Carrying extra pounds also causes chronic inflammation in the body, which research links with a number of diseases, including some cancers.

It all points to the age-old guidance to maintain a healthy weight. It’s much easier to maintain weight than to have to lose it. And nutrition plays a major role — eating too much of certain foods, such as meat products, is linked with a higher risk for colorectal cancer. On the other hand, a study found that women who eat a low-fat diet could reduce the recurrence of breast cancer. Finally, sleep and stress management are key to keeping a strong immune system. It’s all part of a proactive, overall lifetime strategy to ward off cancer and other health threats.