The American Cancer Society reported yesterday that the death rate from cancer in the U.S. has declined. It has fallen 20 percent from its peak in 1991.

The latest figures are based on data from 2009. Overall death rates decreased by 24 percent in men and 16 percent in women. The reduction in the death rate means that nearly 1.2 million lives have been saved.

One factor in the decline is a reduction in smoking. We also are detecting cancer earlier and treating it better.

But cancer remains in second place as a leading cause of death in the U.S. (Heart disease is still the number one cause of death.) A total of 1.66 million new cancer cases are projected to occur in the US in 2013. An estimated 580,350 deaths from cancer will occur.

Most people are aware that smoking causes cancer. But you may not know about the link between cancer and obesity.

Dr. Otis Brawley noted this connection yesterday in his article for CNN Health. He is the chief medical officer of the American Cancer Society.

“The obesity epidemic is also affecting cancer rates in a very negative way,” he wrote. “Indeed, obesity is the second leading cause of cancer.”

Sleep also tends to be overlooked as a factor in both the obesity and cancer epidemics. This link was noted in the recent article, Sleep: A Health Imperative. The paper was developed by the American Academy of Sleep Medicine and the Sleep Research Society.

Multiple studies have shown that failing to get enough nightly sleep increases the risk of obesity. A new review notes that most studies support the idea that restricting sleep increases food intake. These studies suggest that restricting sleep may lead to weight gain.

Recent studies also suggest that a regular lack of sleep may increase risks of several types of cancer. Sleep loss has been linked to breast cancer, colorectal cancer and prostate cancer. Shift workers who stay up all night also may have a higher risk of cancer cell development.

The evidence is clear: Sleep is a critical part of your overall health. So try to get a full night of sleep every night. For most adults, this is seven to eight hours of sleep.

But millions of people are unable to sleep well at night. Contact a local sleep center if you have an ongoing sleep problem.