Study Shows BMI Levels Affect Eating Habits at All-You-Can-Eat Buffets

A new Cornell study found that the eating habits of diners at buffets are associated with their waistlines; at a buffet, overweight patrons will sit an average of 16 feet closer than thinner eaters.
The study observed the behavior of 214 customers at 11 all-you-can-eat Chinese buffets and compared the results across the recorded age, sex, weight and height of diners. The results showed significant disparities between the eating habits of diners of different Body Mass Indexes.
Patrons who had a lower BMI were found to eat less, eat slower and prefer eating with chopsticks, in contrast to their heavier counterparts. Higher BMI levels were associated with larger plates, fork usage and napkins on the table — they tended to approach their meals aggressively. For example, they were more likely to serve themselves food immediately rather than browsing the buffet first.
The study — the work of Prof. Brian Wansink, applied economics and management, and researcher Colin Payne — was published in the August issue of the research journal Obesity. Wansink is the director of Cornell’s Food and Brand lab, a facility dedicated to researching consumer habits about food. His work on the psychology of eating is highly acclaimed and publicized, and has earned him the nickname of “the Sherlock Holmes of Food.”
“This is one of the first studies to actually examine and find a correlation between behavior and body weight,” Wansink said. “These findings are notably consistent with important principles of food intake that have been isolated only in highly controlled — but sometimes artificial — laboratory situations.”
Wansink is known for his eccentric experiments, including a particular study in which he fed unwary test subjects self-refilling bowls of soup, an experiment for which he won the Ig Nobel Prize for improbable research. Currently, Wansink is on leave from the University to serve as the executive director of the U.S. Department of Agriculture’s Center for Nutrition Policy and Promotion until 2009.
In the study, the diners were categorized into lower, middle and upper BMI categories. 50 percent of lower BMI diners would have their napkins on their laps, as opposed to 23.5 percent of those in the upper group. Lower category diners also left an average of 10.6 percent of their food on the plate, nearly twice as much as the upper group’s 6 percent.
According to Gannett Health Services Nutritionist Myra Berkowitz, the findings of the study are highly relevant to the development of good eating habits. “When we’re helping people having difficulty choosing what to eat or dealing with weight issues, one of our suggestions is to hit the dining hall at a less crowded time,” she explained. “That way, they would be free to browse their choices instead of having to choose quickly, and [therefore] be inclined to make better choices.”
Nutritionists like Berkowitz are among the resources that Cornell offers to students experiencing dietary or nutritional concerns. The Cornell Healthy Eating Program also offers extensive information and support through its community workshops, planned programs and website.
For Cornell’s own all-you-can-eat institutions, the welfare of students is central to their planning and operation, says Doug Lockwood, office manager for Cornell Dining.
“We hire consultants and firms to assist us when we build dining halls”, Lockwood said. “The students are always in our minds in whatever we try to do here.”