Flavor perception is a major determinant of food choice behavior and nutritional intake: we eat/avoid foods because they taste good/bad. Eating behavior in turn is directly linked to health. Poor food choice and nutrition increases the risk for (among others) heart disease,1 obesity,2 and type II diabetes,3 which are crucial modifiable risk factors for a host of other diseases, including COVID-194 and Alzheimer’s disease.5-7 Given their devastating impact on quality of life, often in combination with a lack of effective treatment, it is essential to develop interventions to prevent these diseases. Interventions are particularly effective if they can be applied in early life. Thus, this project focuses on ages 2-6, because this constitutes a developmental period during which attitudes toward food undergo major changes (e.g., the emergence of 'pickiness'), which can negatively affect

The initial pilot project, funded through CTSI Pilot Program, sought to understand the development of retro-nasal smell perception and its relation to food consumption behavior in early childhood. Flavor perception relies on a multi-sensory combination of gustatory (taste) and olfactory (smell) signals that are sourced from separate senses.12 During experimental sessions, healthy children (ages 2-6) drank from a series of clear solutions and rated each of them by pointing to a 1-5 pictorial Likert scale. This is an age group that has been understudied in measuring perception. The main goal of the initial study was to establish a method of quantifying a child's experience of food.


Eating behavior interventions are particularly effective if they can be applied in early life. During childhood (2-6 years of age), attitudes toward food undergo major changes, shaping patterns of eating behavior for life.10,13 Any changes made to behavior in early life may have the potential to prevent serious health conditions that can result from long-term abnormal eating behavior (obesity, metabolic disease, heart disease).

The analysis of rating data from odor solutions revealed that across the population of children, odor stimuli were less consistently perceived as negative/positive as compared to adults. This supports our hypothesis that odor perception is plastic during early life, and identifies olfactory perception as a potential target for interventions aimed at altering flavor perception.


Demonstrated benefits are those that have been observed and are verifiable. Potential benefits are those logically expected with moderate to high confidence.

Public Health Practices Collaboration with community organizations will facilitate positive exposure to food smells outside the typical context of mealtimes. Potential.    Community  

Disease Prevention and Reduction Increasing acceptance of healthy foods among young children could lead to reduced risk of obesity, cardiovascular and other diseases. Potential.    Community  

Societal and Financial Costs of Illness Financial burden of diabetes, cardiovascular disease and obesity on the individual and the healthcare system could be reduced by targeting early-life eating behavior.   Economic  

This research has community and economic implications. The framework for these implications was derived from the Translational Science Benefits Model created by the Institute of Clinical & Translational Sciences at Washington University in St. Louis.

Community: Understanding how children perceive flavor and how this relates to eating behavior would facilitate the development of early-life interventions for eating behavior. The aim of these interventions would be to facilitate positive exposure to food smells outside of the typical context of mealtimes. This could be implemented through community organizations for young children, like partnerships for children, preschools, or Head Starts.

Economic: According to the CDC, diagnosed cases of diabetes cost an estimated $327 billion per year, heart disease and stroke cost $216 billion per year, and obesity costs the healthcare system about $173 billion a year. Increasing the acceptance of healthy foods among young children through interventions focused on flavor perception in early-life may lead to a reduced risk of developing these diseases. This presents an opportunity to alleviate the financial burden on individuals and the healthcare system.

Equity Impact

Although the present work has not examined the relation between eating behavior and flavor perception among priority populations, it would be interesting to explore this directly in the future by recruiting low-income populations. Food insecurity has a known impact on food choice and eating behavior.14 It’s likely that the consequential limited access to a variety of foods with complex flavors in early life would alter development of flavor perception. Socioeconomic adversity in early life also further heightens risk for obesity, type 2 diabetes, and metabolic disease15; therefore, knowledge obtained from this study to develop interventions for eating behavior could help to reduce risk among vulnerable populations. 

Impact on Translational Science

This project provides proof of concept for a novel nonverbal rating approach for those ages 2-6. A major impact the project discussed thus far has focused on informing sensory-based interventions for eating behavior, but our method also provides a potential tool to identify children who may benefit even more from such interventions or feeding therapy. For example, the nonverbal rating scale could be applied use among groups with abnormal eating behavior, such as those with eating disorders, or developmental conditions that impact sensory perception, such as autism spectrum disorder.

Next Steps

Future work will identify the factors that drive plastic changes in retronasal odor perception. Exposure is a likely candidate: odors gain meaning (e.g., positive/negative) through experience. To test this hypothesis, we will quantify exposure to the foods associated with the odor stimuli used in the study through questionnaires and a picture-odor matching task. We will also investigate the effect of behaviors that are known to limit exposure and occur typically in the 2-6 year old age range: food pickiness and neophobia (fear of trying new foods). Understanding the effect of exposure on flavor perception will inform interventions in which we can control the context of exposure (i.e., presenting food odors in a rewarding context—a game for example—instead of a negative context—"you have to eat your broccoli!”).

Another question of great interest is not only how taste and smell components of flavor are perceived individually, but how they interact. How does the presence of a pleasant smell affect the ability to overcome a negative taste, and the other way around?


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