Premature infants often undergo postnatal growth failure and show an altered body composition (BC) at termequivalent age (TEA) with lower fat-free mass (FFM) and increased fat mass (FM) than infants born at term.

Critical illness demands objective, targeted nutritional therapy to prevent adverse effects of underfeeding/ over feeding. Thus, all recent societal guidelines recommend indirect calorimetry use to determine energy needs.

Among other important risk factors for severe COVID-19 outcomes, obesity has emerged along with undernutrition-malnutrition as a strong predictor of disease risk and severity. Obesity-related excessive body fat may lead to respiratory, metabolic and immune derangements potentially favouring the onset of COVID-19 complications.

The outbreak of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has presented a global public health emergency. Although predominantly a pandemic of acute respiratory disease, corona virus infectious disease-19 (COVID-19) results in multi-organ damage that impairs cardiopulmonary function and reduces cardiorespiratory fitness.

Body composition is a sensitive marker of infants’ intra- and extrauterine growth quality that can influence short- and long-term outcomes; including retinopathy of prematurity, bronchopulmonary dysplasia (BPD), metabolic health, cardiovascular and neurodevelopmental outcomes.