High Protein and High Energy Intakes and Physical Activity on Growth of Extremely Low Birth Weight Infants

Inclusion Criteria: * 24 weeks \< gestational age \< 32 weeks * inborn or outborn admitted before 24 hours of age * parenteral or enteral nutrition start before 48 hours of age * parental consent Exclusion Criteria: * difficulty in starting physical activity stimulation before 10 days of life * death before 36 W PMA * diagnosis of necrotising enterocolitis (before 36 W PMA) * any major surgery (before 36 W PMA) * congenital syndrome, severe malformations * inborn errors of metabolism * parental consent withdrawn