One-year-old children who failed to thrive in infancy were identified through a specialist clinical service using a conditional weight gain criterion which identified the slowest gaining 5%. Control children of the same age and sex were recruited from the same local geographical area and had the same primary care physician. The food intake and feeding behaviour of the groups was compared using a detailed observational micro-analysis of a lunchtime meal, using a behavioural coding scheme developed for use over the weaning period.
Both food and fluid intake at the test meal were significantly lower in the children who failed to thrive than the controls. There was no significant difference in the energy density of the foods they consumed. As recorded in the behaviour counts at the meal, the mothers of the children who failed to thrive fed them as much as or more than the control mothers fed their children. The children who failed to thrive tended to refuse or reject the offered food more, and also fed themselves significantly less often than the controls. These behavioural differences during the meal accounted for about one third of the difference in energy intake between the groups.
Failure to thrive is a term generally used to describe children whose weight gain is poor in infancy or early childhood (Frank and Zeisel, 1988; Maggioni and Lifshitz, 1995). Poor weight gain can reflect an underlying medical condition (Reilly and Skuse, 1992; Philpot et al., 1999; Giglio and Cnadusso 1997). In most infants it does not; in a 1 year birth cohort in Newcastle-upon-Tyne, for example, no underlying medical condition could be identified in more than 90% of children who failed to thrive in the first 18 months (Drewett et al., 1999). The aetiology is then generally referred to as ‘non-organic’, though this is a rather too general term: there is no justification for assuming that there are no organic causes of variability in weight gain other than those that can be identified as physical illnesses.