Introduction: The sinactive developmental model provides suggests a different way for the brain study by observing the children behavior. In all neurodevelopmental disorders, we can observe autonomic alteration comprising sleep disorders, meal behaviour alteration and self-regulatory impairment. These alterations/impairment are very frequent in autism spectrum disorders (ASD) (1-12). Aim of the present preliminary study is the assessment of metabolic rate in children affected by ASD. Material s and methods. 5 males affected by ASD aged 7-10 years (mean age 6.73\ub13:39), were recruited. The average score at the ADOS scale was 12.24 (SD\ub1 3.29). The control group consisted of 5 males typically developing children (TDC) aged 7 to 11 years (mean age 7.92 \ub1 3.23). Autonomic/Metabolic evaluation: Free-living daily physical activity was measured using either the SenseWear Armband in order to calculate the total energy expenditure (TEE), baseline (REE) and the metabolic physical activity for prolonged periods of time. In general, the SenseWear Armband allows objective monitoring of the lifestyle including duration and sleep efficiency. Results: ASD subjects show values of total energy expenditure (p = 0.0047) and active energy expenditure (p = 0.044) significantly higher compared to control subjects (Table 1). In addition, ASD children have a metabolic intermediate significantly higher than healthy subjects (p=0.015). (Table 1). Finally, the ASD children show a significant reduction of sleep time (p = 0.027) (Table 1). Conclusion: ASD can represents a very significant risk factor for developing sleep disorders and to high energy expenditure, although further studies are needed in this respect