Portion Size Influence on Dietary Behavior
Summary
The phenomenon of portion size has emerged as a pivotal determinant in dietary consumption patterns. Across diverse settings, larger portions of food and beverages have been shown to drive increased energy intake without commensurate rises in satiety, thereby contributing to positive energy balance and weight gain. Mechanisms underpinning this effect include external cues such as packaging, tableware dimensions and value-for-money perceptions which distort individual judgements of an appropriate amount to consume. The influence of portion size operates both acutely, affecting immediate meal consumption, and chronically, by recalibrating norms around what is perceived as a ‘normal’ serving. This recalibration can perpetuate escalating portion sizes in domestic, commercial and institutional contexts, reinforcing obesogenic environments. Interventions at multiple levels—from individual portion-control tools to policy measures capping package sizes—are under investigation to mitigate the upward trends in portion size and related energy intake. A nuanced understanding of these drivers is essential to inform effective public health strategies aimed at fostering sustainable changes to eating behaviour on a global scale.
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Portion Size Influence on Dietary Behavior publication trend
The graph below shows the total number of articles in portion size influence on dietary behavior across all publications each year (not limited to Nature Index journals).
Technical terms
Energy intake: The total amount of energy consumed from food and beverages, typically measured in kilocalories or kilojoules.
Energy density: The amount of energy per unit weight of food, influencing how filling a portion is relative to its caloric content.
Portion distortion: The mismatch between perceived and actual appropriate serving sizes, often leading to overconsumption.
Unit bias: The tendency to regard a single unit or portion of food as the appropriate amount to consume, irrespective of its actual size.
Socioeconomic position: An individual’s social and economic standing, often indexed by education, income or occupation, which may moderate dietary behaviours.
References
- Socioeconomic position and the influence of food portion size on daily energy intake in adult females: two randomized controlled trials. International Journal of Behavioral Nutrition and Physical Activity (2023).
- Differences in Portion Sizes in Brazil, France, and the USA. Foods (2024).
- Food portion sizes: trends and drivers in an obesogenic environment.. Nutrition Research Reviews (2024).
- Visual exposure to large and small portion sizes and perceptions of portion size normality: Three experimental studies. Appetite (2015).
- Portion Size: Latest Developments and Interventions. Current Obesity Reports (2017).
- Downsizing: policy options to reduce portion sizes to help tackle obesity. The BMJ (2015).
About these summaries
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