Good news this Thanksgiving: Compared to 50 years ago, some staples of the Turkey Day table have fewer calories.

The bad news? It probably won't matter, because most Americans will eat too much anyway.

While Americans are notorious for cranking up the calories and portions compared to a generation or so ago, small changes in the nation's diet seem to have buffered Thanksgiving dinner from some, but not all, of our bigger-better mentality.

To find out just what has changed about America's official gut-busting dinner, The Associated Press asked Cornell University's Food and Brand Lab to analyze recipes from the 1950s and compare them to contemporary versions.

Previous studies of non-Thanksgiving recipes by lab director Brian Wansink had found that calorie counts for many classic cookbook recipes have ballooned by nearly 40 percent during the past 70 years.

But Thanksgiving staples didn't follow that trend.

Calorie counts for five of the eight recipes tested actually dropped by almost a third when comparing 1956 Better Homes and Gardens recipes to the 2006 edition of the "Better Homes and Gardens New Cookbook," changes Wansink attributed partly to the use of lower-calorie ingredients, such as low-fat milk instead of cream. Surprisingly, some serving sizes went down over the decades too.

Per-serving calorie counts dropped an average of 102 calories for green beans with almonds, stuffing, mashed potatoes, candied sweet potatoes and pumpkin pie. They went up 26 calories for rolls and were essentially unchanged for corn and candied carrots.

That puts the total calorie count for a contemporary Thanksgiving dinner of those eight fixings, plus a turkey drumstick, at 2,057 calories. The tally for 1956 was 2,539, according to Cornell researcher Laura Smith.

But those numbers are accurate only if you eat proper serving sizes. And when was the last time you measured out six ounces of candied sweet potatoes or called it a day after just one roll? Especially on Thanksgiving.

Wansink's research repeatedly has shown that controlling portions is not something Americans today are skilled at.

"There might be a little less butter put in the dressing, or there might be fewer marshmallows on the sweet potatoes," he says. "But where you end up messing with them, you end up serving up a lot more than your grandfather served himself."

Even the plates on which Thanksgiving is served have grown since a generation ago (by more than a third according to Wansink's studies). And Wansink's research has shown a link between larger plates and larger portions. Put simply, a little lump of mashed potatoes can look awfully lonely on a foot-wide plate.

Wansink added that even in cases where recipes are about the same size, today's families are smaller. That means more per person.

Even the turkeys are bigger. Today's big-breasted birds on average are 10 pounds heavier at slaughter compared to 1950, according to federal data. Recipes from the '50s actually included roasting instructions for 5-pound birds. Good luck finding one that small today.

Joan Salge Blake, a nutrition professor at Boston University and spokeswoman for the American Dietetic Association, thinks the tradition-bound nature of the Thanksgiving meal probably played a role in keeping the recipe calorie counts down.

"These are Grandma's recipes," which are less likely to change over generations, she says.

Nancy Hopkins, deputy editor of food and entertaining for Better Homes and Gardens, isn't surprised by Wansink's findings. She says her company has seen consumers increasingly ask for healthier options, including for Thanksgiving.