With the holiday season on the horizon, it’s time to start thinking about maintaining a healthy weight and avoiding the diet and exercise pitfalls that come after the most wonderful time of the year.

Getting one’s weight in check before the holiday season may be especially important, as one study found that a person’s weight going into the holiday season has a large impact on how much their weight will increase. According to the study, overweight individuals gained nearly five times as much weight as the general population between Thanksgiving and New Year’s.

But the issue is more serious than having trouble fitting back into that favorite pair of jeans.

Many people are aware that being overweight can increase the risk of heart disease, stroke, diabetes, high blood pressure and kidney disease. Fewer may realize that it increases the risk of some forms of cancer. The National Cancer Institute estimates that in 2007, 4 percent of cancer cases in men and 7 percent of cancer cases in women were related to obesity.

According to the American Cancer Society, there is a clear link to weight issues and numerous types of cancer such as breast (in women past menopause), colon and rectum, endometrium (lining of the uterus), esophagus, kidney and pancreas.

It is also believed that there is increased risk of cancers of the gallbladder, liver, cervix, ovaries, more aggressive forms of prostate cancer, non-Hodgkin lymphoma and multiple myeloma in some cases. There are a number of possible reasons for the increased risk, but the general thought is that increased insulin levels and excess hormones produced by fat cells may contribute to cancer cell growth.

Current projections estimate that by 2030, there will be about 500,000 additional cases of cancer in the United States due to individuals being overweight or obese. The good news is that growing evidence suggests weight loss may reduce that risk.

Because weight-gain is the result of consuming more calories than the body burns, the first step to controlling and maintaining a healthy weight is to examine one’s diet. The U.S. dietary guidelines recommend eating nutrient-rich foods such as fruits and vegetables, whole grains, lean protein, fat-free or low-fat dairy products, legumes (beans), nuts and seeds.

For the most part, individuals should avoid sweetened beverages, refined grains (think pasta, white bread, etc.) and fried foods or foods made with butter or shortening.

The second step is to increase physical activity, which should include a combination of aerobic and strengthening exercises. Adults should strive for 2.5 hours of aerobic exercise a week, and those looking to lose weight should strive for five hours of moderate activity (like walking) a week.

At least two days a week of strengthening exercises will also help to burn more calories, reduce injury and maintain bone-strength.

Whether making dietary changes or increasing physical activity, start with changes that are manageable. Any diet or exercise program that is unsustainable for the long-term will ultimately prove ineffective.

For some, it’s equally important to examine the mental or emotional aspects that may lead to being overweight or obese. Speaking with a counselor or healthcare professional about the emotional triggers that may lead to overeating, or participating in stress-relieving exercises like yoga or meditation are extremely successful in helping people to manage and control their weight.

Finally, in cases where a physician deems it appropriate, there are medical treatments that can assist with weight loss. This includes medication and bariatric procedures for extreme cases. While many of these methods have proven results, it is still recommended to start with lifestyle changes tied to diet and exercise.

Before this holiday season gets the better of your waistline, start to examine these lifestyle choices. There’s no reason to wait until the New Year to make changes that will improve your health and help to ensure that you and your family will enjoy more holidays to come.

Kevin Woods, MD, M.P.H, is chief of interventional endoscopy, gastroenterology and nutrition at Cancer Treatment Centers of America at Southeastern Regional Medical Center in Newnan, Ga.