Restaurants get a bad rap for serving gargantuan portions of food and contributing to Americans' expanding waistlines. But what if something in your home were equally guilty? Something as innocent as . . . "Joy of Cooking"?
The classic cookbook, first published in 1931, has done some girth-expanding of its own, a study has found.
Published as a letter Tuesday in the Annals of Internal Medicine, the report examined 18 classic recipes found in seven editions of the book from 1936 to 2006. It found that calorie counts for 14 of the recipes have ballooned by an average of 928 calories, or 44%, per recipe. And serving sizes have grown as well.
Take beef stroganoff: In the 1997 edition, the recipe called for three tablespoons of sour cream. The 2006 edition calls for one cup.
Then there's waffles: In 1997, the basic recipe made 12 six-inch waffles; in 2006, the same ingredients made about six waffles.
Overall, the scientists found, changes in ingredients and serving sizes led to a 63% increase in calories per serving in 17 of the recipes between 1936 and 2006.
"When we talk about obesity, people like to plant the source of the issue on away-from-home dining," said Brian Wansink, the study's co-author and director of Cornell University's Food and Brand Lab. "But that raised the thought in my mind: Is that really the source of things?. . . . What has happened in what we've been doing in our own homes over the years?"
Wansink and co-author Collin Payne, assistant professor of marketing at New Mexico State University in Las Cruces, said they wanted to quantify how home cooking had changed, but knew that doing it anecdotally wasn't scientific. So they turned to cookbooks, settling on "Joy of Cooking" because of its history and the fact that it had enough recipes carried through all editions.
In addition to beef stroganoff and waffles, recipes chosen for analysis included macaroni and cheese, goulash, Spanish rice, brownies, sugar cookies and apple pie.
Wansink said similar calorie increases were found in other enduring recipe books such as the "Better Homes and Gardens Cook Book."
The study found that some of the added calories in the dishes came from a substitution of ingredients -- extra meat instead of vegetables, for example. Back in the day, meat was expensive, so less of it was used, he said.
In other recipes, Wansink said, sauces were added, or more butter or sugar, or extras such as nuts and raisins. "They're now there for a little more excitement," he said.
Cultural shifts may have also had an effect on recipe ingredients and portion sizes, Wansink added. Families have gotten smaller, so a dish that once was consumed by eight people is now consumed by four.
And because sizes of dinner plates have grown over the years, a standard 2-ounce portion of pasta can now look diminutive.
Jeannie Gazzaniga-Moloo, a Roseville, Calif.-based registered dietitian and spokesperson for the American Dietetic Assn., said she was surprised by the findings.
"I would have expected that with the increasing awareness of nutrition, the calories would have been lower or stayed the same," she said.
Beth Wareham, editor of the 2006 edition, is not losing sleep over the study.
"It's such a tiny number of recipes. It's really a non-event," she said.
She said that the book has become more healthful overall, booting out many processed foods in favor of fresh ingredients. The 2006 edition has a chapter on nutrition written by Dr. Walter Willett, chairman of the nutrition department at the Harvard School of Public Health.
In putting together the latest edition, writers and recipe-testers used their common sense in terms of ingredients and serving sizes, Wareham said -- and they figured readers have some common sense of their own.
"We give Americans credit," she added, "for knowing that eating a brownie is not as good as eating a plate of whole grains and vegetables."