A recent study by researchers in the Penn State Department of Nutritional Sciences indicates that an increased variety of food options can lead individuals to select greater quantities of food, particularly calorie-rich items, potentially contributing to overconsumption. The research, published in the journal Appetite, found that a higher assortment of foods in a buffet setting increased both the total weight of food chosen and the caloric content individuals served themselves before eating.
Study Objectives and Background
John Long, the study's first author and a postdoctoral scholar in food science and nutritional sciences, stated that the research aimed to identify elements within modern food environments, such as excessive variety, that contribute to increased food consumption.
The objective is to utilize this understanding to inform the redesign of environments, such as university dining halls, to support healthier dietary choices.
Previous studies, including those at Penn State, have also indicated that consuming from a plate with multiple different foods can increase calorie intake.
Methodology
The study recruited 50 participants, aged 18 to 65, who attended three sessions over three weeks. During each session, participants selected a meal using a virtual reality (VR) buffet. The VR buffet presented either nine, 18, or 27 distinct food choices. The proportion of high-energy-dense foods (e.g., cookies) and low-energy-dense foods (e.g., vegetables) remained consistent across all three levels of variety. To ensure hunger, participants were instructed to abstain from exercise, food, and caffeine for several hours prior to each visit.
Participants used VR headsets and video game-style controllers to make their food selections in a virtual restaurant environment. The VR system precisely recorded the weight and calorie content of their chosen meals, differentiating between high and low-energy-density items. Prior research conducted by the team validated the accuracy of food selections made in a VR buffet compared to a real buffet, allowing for efficient and cost-effective experimentation.
Key Findings
The study observed a significant impact of food variety on selection:
- Participants presented with nine food items selected approximately 600 grams of food.
- Those with 18 or 27 food items selected over 900 grams of food.
While an apparent upper limit for the total weight of food selected was observed as variety increased, the calorie count followed a different pattern:
- Nine food items: Resulted in an average selection of 850 calories.
- 18 food items: Led to approximately 1,320 calories, representing about a 55% increase compared to the nine-item option.
- 27 food items: Resulted in nearly 1,500 calories, an increase of approximately 75% compared to the nine-item option.
Researchers noted that with more options available, participants demonstrated a higher likelihood of choosing calorie-dense foods. This suggests that the abundance of food choices in modern environments may contribute to individuals consuming more calories than required.
Influence of Personality Traits
Participants were also surveyed on five major personality traits: openness, extraversion, agreeableness, neuroticism, and conscientiousness. Among these, conscientiousness was the only trait that demonstrated a difference in food selection behavior. Individuals scoring higher in conscientiousness, a trait associated with self-discipline, were less influenced by increased food variety. They added fewer calories from energy-dense foods compared to participants with lower conscientiousness scores when more options were available.
Implications for Food Environment Design
The researchers expressed a goal for this study to inform the redesign of food environments. They suggest that despite public health warnings about diet, the persistence of conditions like the obesity epidemic indicates that current food environments may override individual efforts to limit intake. The aim is to use these findings to design eating environments that promote health rather than overconsumption. The study suggests that increased awareness of how variety influences eating choices could aid in making healthier decisions.