Linking Eating Behavior to Flavor Perception in Early Childhood

Summary

Flavor perception is a major determinant of food choice behavior and nutritional intake: we choose whether to eat or avoid foods based on how they taste. Eating behavior is directly linked to health. Poor food choice and nutrition increases the risk of developing heart disease,¹ obesity,² type II diabetes³, and other health conditions. These health conditions can then increase the risk of other diseases, including COVID-19 and Alzheimer’s disease.^5-7 Given the devastating impact of these conditions 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 early childhood (children ages 3-6), because it is a key developmental period during which attitudes toward food undergo major changes (e.g., the emergence of ‘pickiness’), which can negatively affect health.^8-11

Dr. Joost Maier and team sought a Pilot award, through the Clinical and Translational Science Institute Pilot Program, to better understand the development of retro-nasal smell perception and its relation to eating in early childhood. Retro-nasal smell refers to the perception of odors from the oral cavity during eating or drinking. Flavor perception relies on a multi-sensory combination of taste and smell signals that are sourced from separate senses.¹² The main goal of the initial pilot study was to create a method for quantifying a child’s experience of food. During experimental sessions, healthy children (ages 3-6) 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.  More specifically, our perception of flavors is a major determinant of our food choices and attitudes around food. For example, our perception of apple flavor impacts our choice between an apple and something like a dragon fruit, which may be less familiar or pleasant based on our individual experiences. Flavor perception may also be influenced by, or contribute to food attitudes such as picky eating and food neophobia (fear of trying new foods) in young children.

Significance

Eating behavior interventions are particularly effective if they can be applied in early life. Examples of a sensory-based intervention might involve multiple exposures to the flavors of nutritious foods in a positive context, such as a game or engaging activity, in order to facilitate the development of a diverse palate in early childhood. During early childhood (3-6 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 (e.g. obesity, metabolic disease, heart disease) that can result from long-term abnormal eating behavior.

Data from the experimental sessions revealed that odor stimuli were less consistently perceived as negative/positive by children compared to adults. These findings suggest that odor perception can be changed during early life, and identifies smell perception as a potential target for interventions aimed at altering flavor perception.

Although the present work has not examined the relation between eating behavior and flavor perception among priority populations, future research could explore this by recruiting low-income populations. Food insecurity has a known impact on food choice and eating behavior.¹⁴ It’s likely that having limited access to a variety of healthy 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.

Benefits

Demonstrated benefits are those that have been observed and are verifiable.

Potential benefits are those logically expected with moderate to high confidence.

The nonverbal Likert rating scale provides a potential tool to identify children who may benefit from interventions. potential.

Clinical

Diagnostic procedures

In collaboration with community organizations, this research may lead to the development of evidence-based early-life interventions and/or routine approaches that facilitate positive exposure to food smells. potential.

Community

Public health practices

Increasing acceptance of healthy foods among young children could lead to reduced risk of obesity, cardiovascular and other diseases. potential.

Community

Disease prevention & reduction

The financial burden of diabetes, cardiovascular disease and obesity on the individual and the healthcare system could be reduced by targeting early-life eating behavior. potential.

Economic

Societal & financial cost of illness

This research has clinical, 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.¹⁶

Clinical

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 for 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.

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. By increasing acceptance of healthy foods among young children, these interventions may reduce their risk of developing obesity, cardiovascular and other diseases.

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, and therefore alleviate the financial burden that these diseases place on individuals and the healthcare system.

Lessons Learned

Future work will identify factors, such as familiarity or developmental/structural changes that explain why children and adults may perceive smells differently in the context of eating. 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 3-6 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?