Exercise is implicated in modifying subsequent energy intake (EI) through alterations in hunger and/or satiety hormones. Our aim was to examine the effects of aerobic exercise on hunger, satiety regulatory peptides, and EI in obese adolescents. Nine obese girls (age: 13–18 years old, BMI: 33.74 ± 4.04 kg/m ² ) participated in this randomized controlled crossover study. Each participant randomly underwent 2 experimental protocols: control (seated for 150 min) and exercise (exercised for 30 min on a treadmill performed at ventilatory threshold [VT] intensity and then remained seated for 120 min). Leptin, peptide YY _3–36 (PYY _3–36 ), and subjective hunger were measured at baseline as well as 30 min and 150 min, followed by 24-hr EI measurement. Exercise session resulted in an acute increase in PYY _3–36 ( p < .01) without changes in leptin and/or hunger scores. The control session increased hunger scores ( p < .01) and decreased circulating leptin levels ( p = .03). There was a strong effect size for carbohydrate intake ( d = 2.14) and a modest effect size for protein intake ( d = 0.61) after the exercise compared with the control session. Exercise performed at VT intensity in this study appears to provoke a state of transient anorexia in obese girls. These changes may be linked to an increase in circulating PYY _3–36 and maintenance of leptin levels.