The investigators aim to examine the feasibility of individualized diet intervention in children dependent on long-term mechanical ventilator support at home. The investigators will use a multidisciplinary model that will allow for diet modification based on comprehensive nutrition, metabolic and respiratory assessments performed in the subjects' home. the impact of this intervention (for 12 weeks) on body composition and respiratory variables will be assessed.

A strategy of individualized diet intervention and its impact on respiratory and nutritional outcomes in children on long-term mechanical ventilation has not been previously evaluated.

The investigators' objective is to assess the feasibility of individualized diet intervention in children dependent on long-term mechanical ventilator support using a multidisciplinary model. The investigators will optimize energy intake (based on indirect calorimetric measurement) and protein intake (based on recommended intake values) in this group. The subjects will be administered the modified diet for 12 weeks, and a comprehensive nutrition, metabolic and respiratory assessment will be performed before and after intervention, in the subjects' home. The investigators will examine the effect of individualized diet optimization on nutritional status, body composition, CO2 production (VCO2) and minute ventilation (MV).

The investigators hypothesize that optimizing energy and protein intake would be associated with improved nutritional status, particularly increment in LBM, and decrease in VCO2 and MV. If nutritional optimization is associated with positive outcomes in our study cohort, this concept could be generalized to a wider patient population with respiratory insufficiency.

Inclusion Criteria:

- Children aged 1 month to 17 years will be included if they were dependent on at least 12 hours of mechanical ventilation per day via a cuffed tracheostomy tube, with a fractional oxygen requirement (FiO2) less than 0.6, and a leak less than 10% around the cuff at the time of data collection

Exclusion Criteria:

-Intercurrent illness such as fever, seizures and/or infectious disease in the 24 hours preceding the study, and/or respiratory decompensation requiring an increase in ventilator settings of >20% from baseline in the 72 hours preceding the study