'Tis the holiday season, and everyone knows that with so many butterball cookies, chocolate kisses, eggnog and other treats lying around, it's hard to resist. But keep in mind while you're indulging that according to a new study, obesity has the potential to shorten life expectancy by up to eight years.

That's not to say you can't partake in the feeding festivities, but a little restraint never hurt anyone.

A team of researchers at McGill University decided to examine the relationship between body weight and life expectancy. They found that for obese and overweight individuals, the risk of developing diabetes or cardiovascular disease earlier in life increases. This could potentially rob them of two decades of healthy living.

"The pattern is clear - the more an individual weighs and the younger their age, the greater the effect on their health," Dr. Steven Grover, lead study author, said in a statement. "In terms of life-expectancy, we feel being overweight is as bad as cigarette smoking."

As described in the journal The Lancet Diabetes & Endocrinology, Grover and his colleagues based their findings on data from almost 4,000 individuals as part of the National Health and Nutrition Examination Survey.

The results showed that those who were very obese could lose up to eight years of life, while obese and overweight individuals could shorten their lifespan up to six years and three years, respectively.

A normal, healthy weight is having a body mass index (BMI) between 18.5 and 25. Overweight is a BMI of 25-30, obese is 30-40, and very obese is anything over 40.

To calculate your BMI, click here.

The next step, researchers say, is to then use this information to talk with your healthcare professional about ways to adopt a healthier lifestyle so you can experience all its added benefits, including a long and happy life.

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