Slim by Design: Serving Healthy Foods First in Buffet Lines Improves Overall Meal Selection
Given the growing prevalence of obesity, a number of recent studies have examined how to redesign cafeterias and buffets to guide or nudge diners to eat less and eat better. Most studies have focused on one or two foods, such as a fruit or vegetable, in isolation from other food items. What previous research has overlooked is that each food that is taken is either substituted for another food or taken in addition to other foods on the serving line. In this study we looked at how food order impacted selection by individuals at a buffet. Specifically we sought to answer the following questions: Are diners more likely to take the first foods they see? Does taking the first item trigger subsequent choices? Lastly, are there differences in the total number of foods chosen between the two lines?
124 conference attendees served themselves from one of two identical and separate buffet lines with the same food set in opposite order. On one line, cheesy eggs were served first, followed by fried potatoes, bacon, cinnamon rolls, low-fat granola, low-fat yogurt, and fruit. Food on the other line was ordered opposite to that on the first line. A researcher recorded a 1 when a food item was selected and a zero otherwise for each attendee. Participants selected a buffet line randomly and were told to only visit the buffet once.
In the fruit-first line, 86.4% of people selected fruit. Also, just under half of the diners took low-fat yogurt (45.8%), and diners in this line had over 3 times the odds of selecting low-fat yogurt when compared to diners in the other line. They were also less likely to select cinnamon rolls, bacon, potatoes and cheesy eggs than those in the other line (only 16.9%, 5.1%, 16.9%, and 28.8% selected them, respectively). When cheesy eggs were served first over half (53.8%) of people selected them and 44.6% of diners took potatoes and 53.8% took bacon--64.6% took one or the other. Compared to the diners in the fruit-first line, diners passing through the line offering cheesy eggs first had nearly four times the odds of choosing potatoes and over 21 times the odds of taking bacon. It is also important to note that diners took 31% more items when cheesy eggs were served first. Those in this line were also less likely to select the last three foods, granola, yogurt and fruit (16.9%, 20% and 53.8% selected them, respectively).
We concluded that food order dramatically biases what diners take in two ways:
- A high percentage of diners took the first available food; over 75% of the diners in this study took the first food offered. Furthermore, the first three foods a person encountered comprised 66% of all the foods they served themselves.
- The first food they took also biased subsequent selections because of their choice of complementary foods. Diners who passed through the cheesy eggs-first line tended to take similar side items that traditionally compliment eggs: bacon and fried potatoes.
Placing fruit or healthy items at the beginning of the buffet line is an easy, low-cost change that can effectively help people eat better. Adjusting food arrangements is also a win-win strategy that not only nudges consumers to eat better, but also by promotes healthier foods, helping consumers become slim by design.