Just one egg daily reduces nutrient gaps among U.S. adolescents, study shows

By Hugo Francisco de SouzaReviewed by Susha Cheriyedath, M.Sc.Sep 23 2024

U.S. adolescents face significant nutrient deficiencies, but new research highlights how a simple solution—adding one egg a day—can dramatically boost their nutrient intake and improve their health, especially for those at risk of food insecurity.

Study: Eating egg-rich diets and modeling the addition of one daily egg reduced the risk of nutrient inadequacy among U.S. adolescents with and without food insecurity. Image Credit: mdbildes / Shutterstock

In a recent study published in The Journal of Nutrition, researchers in the United States analyzed data from the US NHANES study to evaluate the nutritional status of US adolescents and the impacts of added egg consumption on observed patterns. Alarmingly, over 60% of adolescents were at risk of inadequacy in one or more of calcium, magnesium, choline, and essential vitamins ((e.g., vitamins D and E), potentially due to unhealthy eating behaviors (e.g., late-night snacks).

Encouragingly, the consumption of primarily egg-based dishes was found to improve nutritional outcomes, with consumers exhibiting significantly higher choline, vitamin B2, vitamin D, selenium, lutein + zeaxanthin, docosahexaenoic acid, and protein levels than their egg-avoiding counterparts. These findings emphasize the need for policymakers to enhance the publicity, accessibility, and availability of eggs and similar nutrient-rich foods to reduce the widespread risk of nutrient inadequacy and address the growing concerns of nutrition insecurity in the country and abroad.

Background

‘Food insecurity’ – the state of persons or households financially or otherwise incapable of access to sufficient safe and nutritious food essential for normal growth and development and active and healthy life, is a global health concern. The World Health Organization (WHO) estimates that more than 733 million people (~9% of the human population) experienced acute food shortages in 2023, a growth of 152 million individuals in just four years between 2019-2023.

While more than 70% of individuals suffering from food insecurity live in underdeveloped and war-torn regions, developed households (like those in the United States) are increasingly affected by insufficient nutrient consumption, particularly for children and adolescents.  In 2022, the Dietary Guidelines for Americans (DGA) reported that 17.3% of households with minors experienced food insecurity. The report highlights that adolescents indulge in the worst food habits across human developmental stages, exhibiting poor choices in both nutritional decisions (e.g., junk over homecooked diets) and healthy food habits (e.g., regular mealtimes).

To meet the recommended Dietary Reference Intake (DRI) for optimal US adolescent health, meal plans, including the increasingly popular Thrifty Food Plan (TFP) that aims to balance nutrient adequacy with affordability, face limited success. Unfortunately, a lack of clear scientific evidence on the health outcomes of accessible, inexpensive foods like eggs hinders the development of improved meal plans.  Establishing the dietary outcomes of these food components would allow caregivers and policymakers the information required to pave the way for a healthier, more secure tomorrow.

“Although dishes primarily comprising eggs (e.g., hard-boiled eggs) are considered protein foods, eggs are commonly included as ingredients in other types of dishes (e.g., burritos), as a component of foods in the grain group (e.g., breads), and to a lesser extent some snack foods. This varied distribution of eggs across several food groups presents challenges in terms of understanding their nutrient intake contributions. Nevertheless, eggs provide several additional nutrients that have yet to be evaluated in this context, and few studies, if any, have modeled the impact of the addition of one egg on usual nutrient intakes among US adolescents.”

About the study

The present study aims to evaluate the nutritional contributions of eggs (nutrient exposure scores) on the micronutrient and protein aspects of dietary recommendations (DRI, DGA, and Thrifty Food Plan). It further models the potential benefits of adding one daily egg to the diets of former adolescent participants of the NHANES (2007-2018) study.

Data for the study was obtained from the National Health and Nutrition Examination Survey (NHANES) study, a long-term (2007-2018) nationally representative, continuous, cross-sectional database hosted by the US Centers for Disease Control and Prevention (CDC). Data was collected via in-home interviews, health screening using a mobile examination center (MEC), and follow-up telephonic interviews. Data included demographics (age, sex, weight, height, body mass index [BMI], family poverty-to-income ratio (PIR), and race/ethnicity).

“This study encompass two analytic samples. The first one was used to estimate the mean usual nutrient intake and the percent of adolescents not meeting the nutrient recommendations; and included adolescents aged 14-17 years with complete food security data (i.e., household child food security) and ≥1 reliable 24-h dietary recall (n=3,633). The second one was employed to estimate the TNI and FNI scores and consisted of adolescents aged 14-17 years with complete information on the dietary supplements (i.e., Dietary Supplement and Prescription Medicine Questionnaire (DSMQ)) and with at least one 24-h dietary recall (n=1,822).”

Food security was a key variable, with adolescent participants classified into food-secure and food-insecure categories based on the US Household Food Security Survey Module.  Dietary data was obtained from NHANES records and MEC analyses. The USDA’s Food and Nutrient Database for Dietary Studies (FNDDS) database was used to classify egg-containing diets into ‘primary egg dishes’ and ‘egg ingredient dishes’. The Rao-Scott statistical test and t-tests were used to evaluate the contributions of sociodemographic variables and inter-cohort differences, respectively.

Study findings

Supporting DGA reports, 14% of the current study cohort (ages 14-17) lived in households experiencing food insecurity,  most of whom were non-Hispanic black or Mexican Americans. Additionally, participants presenting obesity (BMI >30) and low income (PIR <1.00) were more likely to belong to food-insecure families. Alarmingly, almost half (49%) of the study cohort never consumed eggs, while 36% and 15% consumed primarily egg dishes and egg-ingredient dishes, respectively.

“…regardless of food security status, more than 80% of adolescents were at risk of inadequacy for vitamins D and E. Only 9%-14% of adolescents had intakes greater than the AI for choline.”

Adolescents consuming primarily egg-based diets and experiencing food security presented significantly better nutritional metrics than other cohorts, particularly in protein and essential micronutrient categories. Modeling the addition of one egg per day to the diet significantly improved nutrient intakes across all groups, including those at high risk of nutrient inadequacy. The study showed that even food-insecure adolescents benefited from egg consumption, particularly in areas of choline, vitamin D, and protein intake.

Conclusions

Despite the US being a developed nation with limited food scarcity, more than 60% of the present study cohort (n = 5,455) suffered from nutrient insufficiency (particularly in proteins and essential micronutrients such as vitamin D, calcium, magnesium, and choline), highlighting adolescents as a high-risk population in dietary investigations.

Almost half of the participants reported rarely or never having consumed eggs. Participants who consumed primarily eggs as part of their diets had significantly reduced nutrient inadequacies. Modeling findings revealed that adding a single egg per day substantially improved nutrient outcomes across all evaluated cohorts, though food-insecure participants were expected to benefit the most.

“Efforts aimed at enhancing the accessibility and availability of nutrient-rich foods are crucial in lessening the nutrition risk for all adolescence, and considering the prevalence of food and nutrition insecurity more tailored strategies may be needed.”