BACKGROUND: To compare the energy and macronutrient intake responses to equivalent energy deficits induced by diet (food restriction) and exercise in adolescents with obesity. METHODS: Fourteen 12-15years old obese adolescents completed three experimental conditions (08:00am to 07:30pm) in a randomized crossover design: i) control session (CON); ii) diet-induced 25% energy depletion (Def-EI), iii) and an exercise-induced 25% energy depletion (Def-EX). The sessions order was either CON/Def-EI/Def-EX or CON/Def-EX/Def-EI as the deficit corresponded to 25% of the energy ingested at lunch on the control day (CON) and was imposed either by exercise (Def-EX) or diet (Def-EI). Ad libitum EI and macronutrients preferences were assessed at dinner and appetite sensations assessed using visual analogue scales. RESULTS: Mean BMI was 36.6+/-5.0kg/m2 (z-BMI: 2.40+/-0.29). The individually calibrated 25% energy deficit represented 254+/-92kcal. Ad libitum EI was significantly higher during both Def-EX (971+/-225kcal) and Def-EI (949+/-246kcal) compared with CON (742+/-297) (p<0.05). The relative energy ingested derived from fat was significantly higher on both Def-EX (36.6+/-10.9%) and Def-EI (36.9+/-13.1%) compared with CON (21.6+/-7.8%) (p<0.05). The energy derived from carbohydrates was significantly lower on both Def-EX (48.3+/-9.0%) and Def-EI (44.4+/-17.3%) compare with CON (61.1+/-10.1%) (p<0.05). Appetite sensations were not different between conditions. The induced energy deficit was negatively correlated with the ad libitum EI difference between the exercise and the control session (EI Def-EX - EI CON) (r=-0,643 p<0.05) and positively correlated with the EI difference between the dietary restriction and the control session (EI Def-EI - EI CON) (r=0,569 p<0.05). CONCLUSION: Equicaloric exercise- or diet-induced energy deficits could lead to similar EI compensation in obese adolescents but this EI compensation might be influenced by the magnitude of the deficit