The effects of breakfast consumption on energy intake and the responses to foods consumed later in the day remain unclear. Twelve men of healthy body weight who reported regularly consuming breakfast (mean ± SD age 23.4 ± 7.3 y; BMI 23.5 ± 1.7 kg/m(2)) completed 2 trials using a randomized crossover design. Participants were provided with a 1050-kJ liquid preload 150 min after consuming a standardized breakfast (B) (10% daily energy requirement and 14, 14, and 72% energy from protein, fat, and carbohydrate, respectively), or no breakfast (NB). Blood glucose and serum insulin responses to the preload (area under the curve) were higher in the NB condition (P < 0.05). Plasma FFA responses to the preload were higher in the NB condition (P < 0.01). Plasma glucagon-like peptide 1 (P < 0.01) and plasma peptide Y (P < 0.05) responses were higher after the preload in the B condition. Desire to eat, fullness, and hunger ratings collected immediately prior to consuming the preload were all different from the fasting values in the NB condition (P < 0.05). Thus, immediately prior to consuming the preload, the fullness rating was lower and hunger and desire to eat ratings were higher in the NB condition (P < 0.05). Energy intake at the lunchtime test meal was ~17% lower in the B condition (P < 0.01). In conclusion, missing breakfast causes metabolic and hormonal differences in the responses to foods consumed later in the morning as well as differences in subjective appetite and a compensatory increase in energy intake.