DIFFERENTIAL RESPONSE TO EARLY NUTRITION SUPPLEMENTATION - LONG-TERM EFFECTS ON HEIGHT AT ADOLESCENCE

Background. The classical risk approach to predicting who benefits fro m an intervention is unsound because it relies on the theoretical assu mption that those at risk will necessarily benefit. A better approach to systematically test who benefits from nutrition supplementation id proposed using interactive models. Methods. Differential effects of nu trition supplementation during early childhood on stature at adolescen ce were studied in 245 males and 215 females to identify determinants of long-term benefit from food supplementation. Factors studied includ ed family socioeconomic status (SES) and children's home diet and diar rhoea during the first 3 years of life. To determine whether a factor conferred benefit, the statistical significance of the interaction bet ween this factor and the intervention was tested. Data from the INCAP supplementation trial in Guatemala and from the follow-up of the same subjects at adolescence were used. Results. Ordinary least squares (OL S) showed that high rates of diarrhoea in males and poor SES in female s were significant determinants of benefit from supplementation atadol escence, and that the effects were mediated by length at 3 years old. Results of two-stage least squares (2SLS) analysis showed that length at 36 months, maturation and maternal height were significant determin ants of height at adolescence but SES was not. Conclusions. Nutrition supplementation in early childhood has long-lasting effects on body si ze and the larger benefits acquired by some groups of children remain throughout early adulthood. The relevance of these findings for screen ing and targeting of nutritional interventions is discussed.