Study shows just one egg a day reduces nutritional deficiencies in American adolescents

American adolescents face significant nutrient deficiencies, but new research highlights how a simple fix (adding one egg a day) can dramatically increase their nutritional 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 nutritional deficiencies in American adolescents with and without food insecurity. Image: mdbildes / Shutterstock

In a recent study published in The magazine for nutrition, Researchers in the United States analyzed data from the US NHANES study to evaluate the nutritional status of American adolescents and the impact of additional egg consumption on observed patterns. Alarmingly, over 60% of adolescents were at risk of deficiency in calcium, magnesium, choline, and essential vitamins (e.g., vitamin D and E), possibly as a result of unhealthy eating behaviors (e.g., late-night snacking).

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

Background

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

While over 70% of food-insecure individuals live in underdeveloped and war-torn regions, developed households (such as those in the United States) are increasingly affected by inadequate nutritional intake, 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 engage in the worst eating habits across all stages of human development, making poor choices in both dietary decisions (e.g., junk food over home-cooked diets) and healthy eating habits (e.g., regular mealtimes).

In meeting the recommended Dietary Reference Intake (DRI) for optimal health in American adolescents, meal plans, including the increasingly popular Thrifty Food Plan (TFP), which aims to balance nutrient adequacy with affordability, have had limited success. Unfortunately, a lack of clear scientific evidence on the health outcomes of accessible, low-cost foods like eggs hampers the development of improved meal plans. Determining the nutritional outcomes of these food components would provide caregivers and policymakers with the information needed to pave the way to a healthier, safer future.

“Although dishes that primarily contain eggs (e.g., hard-boiled eggs) are considered protein-rich foods, eggs are often included as ingredients in other types of dishes (e.g., burritos), as part of foods in the grain group (e.g., bread), and to a lesser extent in some snack foods. This diverse distribution of eggs across food groups presents challenges for understanding their contributions to nutrient intake. 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 a single egg on usual nutrient intakes among U.S. adolescents.”

About the study

The current study aims to evaluate the nutritional contributions of eggs (nutrient exposure scores) to 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 in the NHANES (2007-2018) study.

Data for the study were 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 U.S. Centers for Disease Control and Prevention (CDC). Data were collected through home interviews, health checks using a mobile examination center (MEC), and follow-up telephone interviews. Data included demographics (age, sex, weight, height, body mass index [BMI]poverty-to-income ratio (PIR) of families and race/ethnicity).

“This study includes two analytic samples. The first was used to estimate mean usual dietary intake and the percentage of adolescents not meeting dietary recommendations; and included adolescents aged 14–17 years with complete food security data (i.e., household food security) and ≥1 reliable 24-hour dietary recall (n=3,633). The second was used to estimate TNI and FNI scores and included adolescents aged 14–17 years with complete dietary supplement information (i.e., Dietary Supplement and Prescription Medicine Questionnaire (DSMQ)) and at least one 24-hour 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 were obtained from NHANES records and MEC analyses. The USDA Food and Nutrient Database for Dietary Studies (FNDDS) database was used to classify egg diets into “primary egg dishes” and “dishes with egg ingredients.” The Rao-Scott statistical test and t-tests were used to evaluate the contributions of sociodemographic variables and intercohort differences.

Research results

Supporting DGA reports, 14% of the current study cohort (ages 14-17) lived in food insecure households, most of whom were non-Hispanic Black or Mexican Americans. Additionally, participants with obesity (BMI >30) and low income (PIR <1.00) were more likely to be in food insecure households. Alarmingly, nearly half (49%) of the study cohort never ate eggs, while 36% and 15% primarily ate egg dishes and dishes with egg ingredients, respectively.

“…regardless of food security status, over 80% of adolescents were at risk of vitamin D and E deficiency. Only 9%-14% of adolescents had intakes higher than the AI ​​for choline.”

Adolescents who consumed a primarily egg-based diet and experienced food security showed significantly better nutritional values ​​than other cohorts, particularly in the protein and essential micronutrient categories. Modeling the addition of one egg per day to the diet significantly improved nutritional intake in all groups, including those at high risk for nutritional deficiencies. The study showed that even food-insecure adolescents benefited from egg consumption, particularly in terms of choline, vitamin D, and protein intake.

Conclusions

Although the US is a developed country with limited food scarcity, over 60% of the current study sample (n = 5,455) suffered from nutrient deficiencies (particularly protein and essential micronutrients such as vitamin D, calcium, magnesium, and choline), suggesting that adolescents are a high-risk group in nutrition research.

Nearly half of participants reported rarely or never eating eggs. Participants who primarily ate eggs as part of their diet had significantly fewer nutritional deficiencies. Modeling findings showed that adding one egg per day significantly improved nutritional outcomes across all cohorts evaluated, although food-insecure participants were expected to benefit the most.

“Efforts aimed at improving the accessibility and availability of nutritious foods are critical to reducing nutritional risk for all adolescents. Given the prevalence of food and nutrition insecurity, more tailored strategies may be needed.”