Nutritional impact of supplementation in the INCAP longitudinal study: analytic strategies and inferences. Nutritional supplementation, psychosocial stimulation, and growth of stunted children: the Jamaican study. Effect of early, short-term supplementation on weight and linear growth of 4-7-mo-old infants in developing countries: a four-country randomized trial. Effects of yogurt supplementation on the growth of preschool children in Beijing suburbs. Developmental effects of short-term supplementary feeding in nutritionally-at-risk Indonesian infants.
From 1969 to 1977 a supplementation trial was conducted in Guatemala to ascertain the effects on physical and behavioral outcomes of improved nutrition in pregnant women and in preschool children. This paper reviews different strategies to analyze the effect of the intervention on physical growth. One strategy compares outcomes in two villages that were randomly allocated to receive Atole, a supplement containing high amounts of protein and energy, with values in two other villages that received Fresco, a beverage containing no protein and little energy. Both supplements contained micronutrients. This comparison of village means gives a probability significance statement (P < 0.005) that the difference in growth was because of the supplement intervention, although it does not specify the aspect of the intervention that caused the effect. Complementary strategies increase the credibility that the effect of the supplement was nutritional. Thus, analysis of the dose response with increasing supplement intake within the villages excludes the possibility that the above findings were the result of knowing which villages received which supplement (i.e., measuring biases). A greater effect in those most likely to respond nutritionally also increases the credibility that the mechanism was nutritional. In studying other behavioral and biomedical impacts of this supplementation intervention, analyses for credibility should always be included. The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo. The effect of supplementation on growth was tested by means of four similar controlled randomized trials in the Congo (n = 120), Senegal (n = 110), Bolivia (n = 127), and New Caledonia (n = 90). Four-month-old infants were randomly allocated to supplement or control groups. A cereal-based precooked porridge was offered twice daily for 3 mo and consumption was monitored. Both groups were free to eat local food. At 7 mo of age, all infants were still breast-fed in the Congo, Senegal, and Bolivia compared with 47% in New Caledonia. Mean daily consumption of the supplement varied among countries (558-790 kJ/d). Mean length at 4 mo was lowest in Bolivia, higher in Senegal and the Congo, and near the National Center for Health Statistics reference in New Caledonia. The mean 4-7 mo length increment was 0.48 cm higher for supplemented than for control infants in Senegal (P < 0.05), whereas weight increments did not differ. No significant effect was found in the other countries. To investigate the effect of yogurt supplementation on the growth of preschool children in Beijing suburbs.
                Four hundred and two preschool children (217 males, 185 females), aged 3-5 years, whose height for age and/or weight for age were less than the reference level, were selected as subjects from 7 kindergartens in Beijing Fangshan District. The subjects were divided randomly into control group (CG, 201) and yogurt supplemented group (YG, 201). Each subject in YG was given one serving of yogurt (125 g) for 5 days a week from March to December in 2001, while nothing additional was provided to CG. All subjects kept their usual diet during the study. Anthropometry (body height and weight and upper-arm circumference) and the bone mineral density (BMD) of forearm were measured every 3 months. Disease status and dietary intake were also recorded and assessed.
                The intake of calcium, zinc, and vitamin B2 in YG was significantly higher than that in CG. The incidence and duration of upper-respiratory infection and diarrhea of children in YG were significantly less than those in CG. The height gain of children in YG was significantly higher than that in CG after yogurt was supplemented for 3, 6, and 9 months (P<0.05) (1.90+/-0.49 cm vs 1.77+/-0.54 cm, 3.83+/-0.57 cm vs 3.64+/-0.66 cm and 5.43+/-0.69 cm vs 5.24+/-0.76 cm, respectively). The weight gain of children in YG was significantly higher than that in CG after yogurt was supplemented for 3, 6, and 9 months (P<0.05) (0.70+/-0.43 kg vs 0.49+/-0.35 kg, 0.98+/-0.62 kg vs 0.80+/-0.60 kg and 1.42+/-0.76 kg vs 1.20+/-0.67 kg, respectively). The BMD of children in YG was significantly higher than that in CG after yogurt was supplemented for 9 months (P<0.05) (0.415+/-0.058 g/cm2 vs 0.400+/-0.065 g/cm2).
                Yogurt is beneficial to the improvement of calcium, zinc, and vitamin B2 intake, the decreasing of the incidence and duration of upper-respiratory infection and diarrhea, and the promotion of the health and the growth and development of preschool children. This study assessed the developmental effects of supplementary feeding over 90 consecutive days on infants aged 6-20 mo at six tea plantations in West Java, Indonesia. Every day except Sunday, the infants attended day-care centers distributed throughout the plantations. Twenty centers and 113 infants were selected; the infants in 9 centers received a dietary supplement, while the infants in 11 centers served as control subjects. Supplements were given twice a day providing, on average, 10.66 kJ (400 kcal) and 5 g protein/d. Measurements of body growth, dietary intake, and mental and motor development were made on all infants. Supplementary feeding had significant effects on weight gain and on motor development. Changes in caloric intake were independently associated with changes in weight and in motor test scores. The data suggest that the effects of the supplement may not have followed a simple mechanistic relationship from intake to weight change to motor development, but, rather, intake may have affected both growth and development domains simultaneously.
The scarcity of available studies and their heterogeneity makes it difficult to reach any firm conclusions. The review findings suggest supplementary feeding has a negligible impact on child growth; however, the pooled results should be interpreted with great caution because the studies included in the review are clinically diverse. Future studies should address issues of research design, including sample size calculation, to detect meaningful clinical effects and adequate intervention allocation concealment. In the meantime, families and children in need should be provided appropriate feeding, health care and sanitation without waiting for new RCTs to establish a research basis for feeding children.