In children aged ≥6 months in low‑ and middle‑income settings, does providing one boiled egg daily improve linear growth and prevent stunting or underweight, assuming no egg allergy?

Daily Egg Supplementation for Growth in Low- and Middle-Income Settings

Providing one boiled egg daily to children ≥6 months in low- and middle-income settings is supported for nutritional purposes, with the critical caveat that eggs should be introduced as cooked (boiled) egg around 6 months of age to simultaneously reduce egg allergy risk while providing high-quality protein and micronutrients.

Timing and Form of Introduction

The evidence strongly supports introducing eggs between 4-6 months of age, with around 6 months being the preferred target, but not before 4 months 1, 2. The form matters significantly: cooked egg (such as boiled) should be the first exposure rather than egg in baked goods, as this appears more protective against egg allergy 2, 3. Population-based data demonstrates that first exposure as cooked egg at 4-6 months reduced egg allergy risk by 80% compared to first exposure as egg in baked goods (adjusted OR 0.2,95% CI 0.06-0.71) 3.

The World Health Organization specifically recommends introducing eggs daily or as frequently as possible beginning at 6 months corrected age, aligning with the optimal window for allergenic food introduction 2. This timing is critical because delayed introduction substantially increases allergy risk—introduction after 12 months carries a 3.4-fold increased risk of egg allergy compared to introduction at 4-6 months 3.

Allergy Prevention Through Early Introduction

Once eggs are successfully introduced, they should be consumed regularly—at least weekly and ideally daily—as part of the infant's usual diet to reduce the risk of sensitization and allergy 2. This recommendation is based on moderate-to-high quality evidence showing that regular egg consumption from 4-6 months reduces egg white sensitization 4, 5. In randomized trials, introduction of whole-egg powder reduced sensitization to egg white by approximately 50% (OR 0.46,95% CI 0.22-0.95) and induced protective IgG4 antibody responses 4.

The American Academy of Allergy, Asthma, and Immunology, American College of Allergy, Asthma and Immunology, and Canadian Society for Allergy and Clinical Immunology jointly recommend introduction of cooked egg around 6 months at home when developmentally ready for all infants irrespective of risk 1.

Risk Stratification and Safety Considerations

For infants with severe eczema or existing egg allergy, eggs should still be introduced between 4-6 months but only after evaluation by an allergist, which may include skin prick testing or specific IgE measurement 2. However, infants with mild-to-moderate eczema can introduce eggs around 6 months at home without specialist evaluation and no pre-introduction testing is required 2.

Critical pitfall to avoid: Approximately 6-8.5% of high-risk infants may react to egg within the first week of introduction despite negative screening tests 4, 6. Therefore, introduce eggs one at a time, wait at least 4 days before introducing another new food, start with small amounts and gradually increase 2. Watch for warning signs including persistent vomiting, severe diarrhea, skin rashes, respiratory symptoms, or lethargy after eating, which require immediate medical attention 7.

Nutritional Context for Growth Outcomes

Iron-rich foods should be prioritized as first complementary foods at 6 months since the baby's iron stores from birth are now depleted 7. Eggs provide high-quality protein and micronutrients that complement iron-rich vegetables and meats 7. Breast milk or formula should remain the primary nutrition source throughout the first year, offered first before solids, with breastfeeding frequency of 3-5 feedings per 24 hours typical at this age 7.

Implementation Algorithm

1. At 6 months chronological age (not corrected age), confirm developmental readiness: good head control, ability to sit with support, and interest in food 7, 2

2. Assess eczema severity: If severe eczema present, refer to allergist before introduction 2; if mild-to-moderate or no eczema, proceed with home introduction 2

3. Introduce cooked (boiled) egg as one of the first complementary foods, starting with 1-2 teaspoons 7, 2, 3

4. Monitor for 4 days before introducing other new foods 2

5. Continue regular consumption at least weekly, ideally daily, once successfully introduced 2

6. Avoid delaying introduction beyond 6 months, as this increases allergy risk substantially 3

Maternal diet consideration: Routine maternal egg avoidance during pregnancy or breastfeeding is not recommended for allergy prevention 2.