The relationship between components of infant energy expenditure and childhood body fatness.

Objective: To investigate whether any component of infant energy expenditure is related to fatness in early childhood, and whether infant fatness is related to childhood variables.
Design: Longitudinal investigation of infants studied at 12 weeks and followed up at 2.5 to 3.5 years of age.
Subjects: 30 healthy full-term infants selected from the general population.
Measurements: Sleeping metabolic rate, total energy expenditure, anthropometry and behaviour at 12 weeks; anthropometry, body composition and behaviour in follow-up.
Results: Energy expenditure at 12 weeks (minimal metabolism, total energy expenditure, energy expended on physical activity, behaviour) showed no relationship with later fatness. Infant fatness (skinfold thicknesses and percentage fat) showed in contrast a strong relationship with childhood fatness. Infant fatness also predicted childhood behaviour.
Conclusions: These data do not support the theory that reduced energy expenditure in early infancy is related to later fatness. However, infant fatness influences both later fatness and activity patterns.