Brian Wansink, Aner Tal, Mitsuru Shimizu. First Foods Most: After 18-Hour Fast, People Drawn to Starches First and Vegetables Last. Arch Intern Med. 2012;172(12):961–963. doi:10.1001/archinternmed.2012.1278
Author Affiliations: Dyson School of Applied Economics and Management, Cornell University, Ithaca, New York.
Short-term food deprivation of 18 to 24 hours is fairly common.1- 3 It can be medically imposed before blood draws or surgery, or it can be self-imposed in the case of serious dieting, religious fasts, and chaotic work schedules.4,5
Animal studies have examined only calorie levels rather than food types following deprivation.6,7 The question arises: when a food-deprived person finally eats, what foods do they eat first and most? The answer has implications for the precautions that patients, fasters, medical interns, and dieters should take when first serving and eating food after a short period of food deprivation.
A total of 128 participants were recruited from Cornell University for course credit, and they were randomly assigned to 2 experimental conditions: one group was instructed to avoid eating 18 hours prior to a lunchtime study (no food or beverages after 6:00 PM the night before the study), and the control group was not. The study was conducted during 12 weekday lunches involving 10 to 12 participants across both conditions and was approved by the institutional review board.
After arriving for lunch, participants were presented with a buffet of 2 starches (dinner rolls and French fries), 2 proteins (chicken and cheese), 2 vegetables (carrots and green beans), and a beverage. The order of the food on the tables was rotated across sessions to prevent an order bias. The amount of the foods participants served themselves was surreptitiously measured by scales embedded in the tables, and food consumption was unobtrusively videotaped.
After finishing the meal, participants completed a questionnaire in which they indicated if they had skipped breakfast and confirmed the order in which they had first tasted or eaten each of the foods they had for lunch. Intake was determined by deducting the amount left over from the amount served. Across both study groups, participants were similar with respect to BMI, age, and sex. All analyses were performed using SAS statistical software, version 9.2 (SAS Institute Inc). P < .05 was considered statistically significant.
We eliminated people who did not follow fasting instructions from analysis (n=43). However, those were still included in calculating correlations between first food served and calories eaten.
Participants in the control group started their meals with the high-calorie foods (starches and protein) less often than did participants in the fasting condition (44% [20 of 45] vs 75% [30 of 40]; χ2 = 6.83) (P = .01). Although this trend appeared stronger for women (36% [8 of 22] vs 80% [12 of 15]) than for men (50% [11 of 22] vs 66% [16 of 24]), the interaction with sex was not significant. The Table lists the types of foods served by study group consumption; compared with the control group, fasters were more likely to eat a starch first (13% [6 of 45] vs 35% [14 of 40]; χ2 = 5.53) (P = .02) and less likely to eat a vegetable first (56% [25 of 45] vs 25% [10 of 40]; χ2 = 8.16) (P = .005).
Importantly, starting their meal with a particular food led all participants to consume 46.7% more calories of it (128.57 vs 84.91 calories) (F1,122 = 3.89, P = .047). Indeed, in using choice as a binary variable, we found that the food that a person chose to eat first was correlated with how much was served (product-moment correlation coefficient, 0.24; P < .001), and it was correlated with how much of it the person ultimately ate during the entire meal (product-moment correlation coefficient, 0.21; P = .003) .
When a food-deprived patient, faster, medical intern, or dieter first encounters food, the first food they eat may well end up being the food of which they eat the most. In general, they will be most drawn to starches and will eat them instead of nutrient-dense vegetables. Even relatively mild food deprivation can alter the foods people choose to eat, potentially leading them to eat starches first and most.
Hospitals and cafeterias that deal with food-deprived individuals should make healthier foods—vegetables, salads, and fruit—much more convenient, visible, and enticing than starches to avoid such biasing of choices toward potentially less healthy choices. In addition, the serving size of starches can be reduced, or they can be offered in combo meals that balance the amount of starches with protein and vegetables.
Correspondence: Aner Tal, PhD, Cornell Food and Brand Lab, 14B Warren Hall, Ithaca, NY 14853-7801 (firstname.lastname@example.org).
Author Contributions:Study concept and design: Wansink. Acquisition of data: Wansink, Tal, and Shimizu. Analysis and interpretation of data: Tal. Drafting of the manuscript: Wansink and Tal. Critical revision of the manuscript for important intellectual content: Wansink and Shimizu. Statistical analysis: Tal. Obtained funding: Wansink. Study supervision: Wansink.
Financial Disclosure: None reported.
Funding/Support: This research was made possible by support from Cornell University.