Large spreads of food are common at holidays, parties and dining halls. But new research suggests that simply increasing the number of options available may significantly raise the number of calories people put on their plates.
In a study published in Appetite, researchers from Pennsylvania State University examined how food variety influences meal selection in a controlled laboratory setting.
Fifty adults visited the lab on three separate occasions, each one week apart. During each session, participants entered a virtual reality buffet where they selected a meal using handheld controllers. The number of available food items changed at each visit: nine, 18 or 27 options. The proportion of higher-calorie foods, such as cookies, and lower-calorie foods, such as vegetables, remained consistent across all versions of the buffet.
When only nine food items were offered, participants selected an average of about 850 calories. With 18 options, that number rose to roughly 1,320 calories. When 27 items were available, participants selected nearly 1,500 calories, about 75% more than in the nine-item condition.
The total weight of food served also increased with variety, rising from just over 600 grams at the smallest buffet to more than 900 grams at the larger ones. However, while food weight appeared to reach a ceiling as options expanded, calorie selection continued to climb. Participants were more likely to include energy-dense foods when faced with more choices.
“External factors clearly influence what and how much people eat,” said first author John Long, a postdoctoral scholar in nutritional sciences. “But there seems to be a ceiling to the total weight of food selected for a meal, even as variety increases.”
The researchers also examined whether personality traits influenced responses. Among the five major traits measured, conscientiousness stood out. Participants who scored higher in conscientiousness, a trait linked to self-discipline and goal-directed behavior, were less likely to increase their calorie selection when more options were available.
This was a laboratory study using a virtual buffet, and participants selected food rather than consuming it during the experiment. Still, previous work from the same research group suggests that choices made in the virtual setting closely resemble those made at real buffets.
The findings add to a growing body of evidence that eating environments shape intake. Variety can improve diet quality when it increases exposure to fruits, vegetables and other nutrient-dense foods. But when a wide range of energy-dense options is available, the same principle may nudge calorie selection upward.
For everyday eaters, awareness of this “variety effect” may help. Scanning the full spread before serving, starting with smaller portions or prioritizing specific foods can create structure in settings designed around abundance.
The researchers reported that this work was supported by start-up funds provided to the investigators.