Objective: To evaluate the effects of an egg breakfast on lunchtime energy intake in children (age 4–6 years) and adolescents (age 14–17 years). Methods: In 2 randomized crossover trials, participants received either an egg breakfast or an isocaloric bagel breakfast. In both trials, subsequent lunchtime energy intake was the primary outcome. The trial with adolescents also measured each participant's serum ghrelin, serum peptide YY (PYY), and self-assessment of appetite rated using a visual analog scale. Results: Lunchtime food intakes after egg and bagel breakfasts were not significantly different for either age group. Visual analog scale ratings of hunger and satiety were also not different between the 2 treatments in adolescents. Consumption of the egg breakfast led to a significant increase in serum PYY levels (p = 0.0001) in adolescents. However, increased levels of PYY were not correlated with reduced food intake. Conclusion: Short-term food intake in children and adolescents is not differentially altered by an egg breakfast compared to a bagel breakfast.