Eggs are low-cost and rich in many important nutrients, including all essential amino acids [1
], choline, B vitamins, vitamin A, iron, vitamin D [3
], and the xanthophyll carotenoids lutein and zeaxanthin [4
]. Evidence also shows that consuming eggs increases the bioavailability of co-consumed carotenoids [7
] and vitamin E [8
], and also contributes to satiety, an important factor for weight control [9
The most recently available data (2001–2008) on the prevalence of egg consumption show that approximately 20% of the U.S. population reported consuming eggs on a given day [10
], which is unchanged from earlier (1988–1994) estimates [11
]. On a weight basis, Rehm et al. reported a positive trend in egg consumption from 1999–2000 to 2011–2012, albeit of small magnitude [12
In the U.S., food and nutrient intakes vary by sociodemographic characteristics such as age, income, education level, and race-ethnicity [13
]. For instance, Mexican–American and non-Hispanic black children are most likely to have serum vitamin D concentrations levels below the at-risk cutoff [13
]. Individuals from low-income and food insecure households, even those participating in federal food assistance programs, have lower quality diets compared to the general population [15
Data from 2003 to 2006 show that eggs contribute important nutrients to minority race-ethnic groups [16
] and overweight and obese women [17
]. Others demonstrated that egg consumption by Supplemental Nutrition Assistance Program (SNAP) participants did not differ from income-eligible non-SNAP participants [18
Given that eggs are nutritious, low cost, and a part of a wide range of cultural food menus, they have the potential to contribute valuable nutrients to diverse populations including nutritionally vulnerable groups with limited food budgets. Despite recent analyses of population-level trends in egg consumption, further research is needed to better understand patterns of egg consumption across diverse sociodemographic groups, including nutritionally vulnerable groups, in order to inform clinical practice to improve nutrient adequacy. The goal of this research was to (1) describe time trends in frequency and amount of egg consumption; and (2) describe differences in egg consumption by sex, age, income, education, race-ethnicity, SNAP participation status, and food security status. We expected to observe a moderate increase in overall egg consumption over time and heterogeneous trends across sociodemographic groups.
In this cross-sectional, nationally representative study of nearly 30,000 U.S. adults that provided dietary data from 2001–2002 to 2011–2012, approximately one-fifth of individuals reported consuming eggs on the day of the survey in each survey wave. Over this twelve year period, mean per capita egg consumption increased overall and among select sociodemographic groups, including fully food secure individuals and SNAP-ineligible individuals; yet no difference in mean daily intake was observed between levels of food security and SNAP participation status. These findings represent the most up-to-date trends and patterns of egg consumption across diverse sociodemographic groups in the U.S.
Consistent with these findings, Nicklas et al. reported that 20% of adults in NHANES 2001–2008 reported consuming eggs on the day of the survey [10
], and Rehm et al. reported a positive trend in overall egg consumption using NHANES data from 1999–2000 to 2011–2012 [12
]. Cifelli et al. estimated daily egg consumption of 0.52 servings/day (equivalent to 26 g/day) from 2007 to 2010 (NHANES) [33
], which is similar to Rhem et al. (0.50–0.51 servings/day from 2007–2012, equivalent to 25–25.5 g/day) [12
] and to the present study (24.7–25.5 g/day from 2001 to 2012). Consistent with others [18
], we observed no difference in mean daily egg consumption between SNAP participants and eligible non-SNAP participants.
The current work extends this area of research by being the first study to evaluate trends and absolute consumption of eggs across a wide range of sociodemographic groups and doing so over a twelve year contemporary period. Eggs are among the highest quality protein sources, are one of the best sources of micronutrients per calorie, and increase the bioavailability of some co-consumed nutrients (carotenoids [7
] and vitamin E [8
]). Egg consumption promotes positive health outcomes at all ages and all stages of life [34
], and lowers the risk of some cardiovascular events [35
]. Given these health benefits, the results presented here have important implications for reducing disparities in health outcomes and diet quality, in particular among food insecure individuals and SNAP participants who did not increase their consumption of eggs from 2001–2012, whereas their fully food secure and SNAP-ineligible counterparts did. On the one hand, given that chronic disease risk is greater and diet quality is lower among individuals in lower income strata [36
], it is concerning that these individuals are forgoing the additional nutritional benefits that could otherwise be provided by consuming more eggs; yet on the other hand, these results show that more can be done to increase egg consumption among these nutritionally vulnerable groups. Indeed, given their low cost and culinary versatility [34
], eggs may be an ideal food for low-income consumers on fixed budgets.
A potential barrier to increasing the consumption of eggs among low-income individuals is related to the volatility of egg prices, which is more severe than all other major food groups [38
]. For example, the mean annual change (upward or downward) in retail price from 1995–2015 was 2.5% for all foods but 5% for eggs specifically [39
]. Although the own-price elasticity of eggs (the change in consumption of eggs related to the change in their price) is lower than other foods (0.27% change in consumption for every 1% change in price) [40
], dramatic price changes can still elicit meaningful changes in consumption. Much of the annual price volatility of eggs can be explained by the negative impact that major disease outbreaks have had on poultry flocks, most recently in 2003–2004, 2007–2008, and 2014–2015, the most recent of which caused the loss of about 33 million (11%) egg laying hens in the U.S. [38
]; as a result, the price of eggs increased by 14%, 29%, and 8.4% in 2003, 2007, and 2014, respectively [39
]. Further research is needed to quantify the socioeconomic differences in the own-price elasticity of eggs. Additionally, more research is needed to examine the heterogeneity of the cross
-price elasticity of eggs (the change in the consumption of eggs related to the change in price of other foods) across sociodemographic groups, in order to better understand how the price of other foods affects egg consumption across different consumer groups. Additional barriers to increasing egg consumption among low-income individuals may be the neighborhood proximity to food retail outlets, availability of transportation, time and convenience of food preparation, and access to cooking supplies and appliances.
For the general population, barriers to increasing the consumption of eggs include their historical association with cholesterol and thus cardiovascular disease risk [41
]. While eggs do contain a substantial amount of cholesterol, a consistent body of research now shows little evidence to support a clinically significant relationship between dietary cholesterol and serum cholesterol [42
]. Rather than limit dietary cholesterol to a specified threshold, the most recent iteration of the Dietary Guidelines for Americans advises consumers to replace their intake of saturated fatty acids with unsaturated fatty acids (especially polyunsaturated fatty acids) in order to reduce circulating total and low-density lipoprotein (LDL)-cholesterol [43
]. Still, sustained marketing efforts may be needed to fully overcome the negative public association between dietary cholesterol (and eggs) and cardiovascular disease.
Continued advancements in nutrient-enriched eggs (for example, eggs high in α-linolenic acid and docosahexaenoic acid [44
], folate [45
], iodine [46
], and some lipophilic antioxidants [47
]) may appeal to some consumer segments. Yet the potential market for these specialty products is not well understood, and their production partly depends on the availability of specific poultry feed formulations and supply chain infrastructure, and is complicated by the recent downsizing of poultry flocks noted above.
Despite the differences we observed in egg consumption across several sociodemographic groups, some of these differences were of small magnitude (up to 14 grams/day) and the effects on health outcomes may be limited. Previous studies have shown no appreciable effect on risk of type II diabetes [48
], coronary heart disease, and stroke [49
] at consumption amounts of less than one-half egg (~25 grams) or one egg (~50 grams) per day. However, little is known about how small differences in egg consumption affect the probability of nutrient inadequacy, particularly among nutritionally vulnerable populations, which calls for further investigation.
This study does have limitations that warrant discussion. Participants in surveys may not accurately report their food intake in order to simplify the survey process or to impress the interviewer [50
], and some have specifically called into question the validity of self-reported energy intake [52
]. However, self-reported dietary data are nonetheless useful in characterizing food intake patterns [53
]. Additionally, the focus of this study was exclusively on shell egg dishes (such as omelets and quiche, for which eggs were the main ingredient) rather than eggs in mixed dishes (such as baked goods, for which eggs are a minor ingredient), so not all egg consumption was measured. Because eggs are used as an ingredient in a wide variety of dishes that can be categorized as different food groups with disparate nutrient profiles, we limited this analysis to shell eggs in order to improve interpretability and maintain relevance to dietary recommendations. In addition, these findings are only reflective of the U.S. population; egg consumption in other countries may differ.
To the best of our knowledge, this is the first study to examine contemporary trends and patterns of egg consumption by sociodemographic group. The nationally representative design of the dietary survey and large sample size (nearly 30,000 adults) make these findings generalizable to the U.S. adult population. Egg consumption was computed using nearly 180 discrete food items for which eggs was the dominant ingredient, making these findings relevant to a wide variety of consumer food purchases.