The effects of protein supplementation on the growth and skeletal maturation of New Guinean school children

Abstract

SummaryThe response to protein supplementation was studied in 86 Bundi children, aged 7·7 to 13·0 years, in the New Guinea highlands. Group 1 (22 males, 8 females) served as a control and received only their normal school diet, averaging 5440 kJ and 11 g protein per day. Group 2 children (22 males, 8 females) were supplemented with 10 g of protein per day for five days a week and group 3 (18 males, 8 females) received 20 g protein per day. The supplement was skim milk powder and the experiment lasted for eight months. Increments of growth and of skeletal maturation of individuals were analysed, by group, for the eight-month period. Height, weight, skinfold thickness (triceps and subscapular), compact bone breadths of the second metacarpal, and Tanner-Whitehouse bone maturity scores were studied. Supplemented children showed increased growth in height, weight, and periosteal bone breadth, as well as increased increments of skeletal maturation. While unsupplemented children showed increases in skinfold thicknesses, the increments of the supplemented groups did not differ significantly from zero. There were no differences in either the endosteal breadth or the thickness of the compact bone layer of the second metacarpal. Children receiving 20 g of protein displayed consistently greater increments than those receiving 10 g but the differences were significant only in the case of body weight. The relative response of height to protein supplementation was greater than the response of skeletal maturation.