Eating tons of turkey, stuffing, cranberry sauce, green bean casserole, and a variety of pies every Thanksgiving is one of America's most beloved traditions.

 Typically, there's this one unspoken rule on Thanksgiving: Do not think about calories, just eat.

But how much food do you really have to eat to gain a single pound?

The answer isn't simple. There are many who subscribe to the 3,500 calorie rule, based on the findings of scientist Max Wishnofsky in 1958. 

"1 pound contains 3,500 calories. Logically, eating an extra 3,500 calories, or 500 more calories each day for a week, will lead to a 1-pound weight gain," Live Strong reports.

However, some people who study nutrition reject this rule. The idea that with every 3,500 calories burned equals to one pound of weight loss is, "a total myth" according to The Washington Post in a 2015 article.

And Live Strong acknowledges the iffy-state of the 3,500 rule saying, "while the 3,500-calorie rule is used by health-care professionals to help promote both weight gain and loss, and may be a good place to start, weight gain isn't that simple."

So 3,500 isn't the magic number?

It might be — but not for you. Basically, everyone's body and caloric needs are different. Depending on your initial weight, height, gender, and level of activity, you may have to eat more or less calories than someone else. 

So in order to figure out how much you personally would need to eat in one sitting in order to gain a pound, your best bet is to use a calorie calculator, like this one. After you enter your stats, the calculator will tell you how many calories you need to eat in a day to maintain, lose or gain weight. That may come out to an additional 3,500 calories - it may not.

Live Strong seems to concur, citing the Pennington Biomedical Research Center's weight loss calculator as a way to determine how much you personally need to eat in order to gain weight, concluding: "... the number of calories you need to gain a pound depends on your gender, height and current weight."

From now on, probably just tell people this:

"Did you know that the idea that eating an excess 3,500 calories in one day will lead to a one pound weight gain is false? Yeah, it was based on research some dude did in the '50s, and it's not accurate anymore." Then just grab some more cornbread and enjoy every single bite.