Nutrition and growth

Abstract

Long before the present century there was general appreciation of the fact that good growth called for good food and plenty of it. Hopkins’s isolation of tryptophane and his pre-occupation with vitamins always led him to emphasize that something more was required and that satisfactory growth was only possible on a ‘balanced’ diet. By this he meant adequate in all respects—proteins in general, amino-acids in particular, calories, vitamins and minerals (Hopkins 1920, 1925). Since that time everything has gone to vindicate Hopkins’s foresight, but a great many further discoveries have been made about the bearing of nutrition on growth. These have all emphasized the co-ordinated nature of the process, and it is with some of these discoveries that this paper will be concerned. The nutrition of children in this country has been progressively altered in the last 40 years by the provision of cheap milk, school meals and a rising standard of living. At each chronological age, moreover, down to the age of 5, the heights and weights of children have been shown to have risen progressively in a number of countries over the last 50 years and to be still rising (Tanner 1955; Acheson i960). The height of adults has probably risen too (Boyne & Leitch 1954; Boyne i960). With this increase in children’s size has gone earlier maturity and all that this involves. These observations on man recall those which Osborne & Mendel (1926) reported from their rat colony over a period of 15 years. The charges described by them were certainly nutritional in origin and considered to be beneficial in every way. McCay, Maynard, Sperling & Barnes (1939) and others, however (Ross 1959; Berg & Simms 1960), have shown in growing rats that prolonged undernutrition and delayed development after weaning may greatly increase the normal life span, and the subject was reviewed by Silberberg & Silberberg (1955) and Comfort (i960). McCance (1953) suggested that the rehabilitation of undernourished German children after the war might be shortening their expectation of life, and it has even been proposed that a progressive curtailment in the expectation of life may be accompanying the secular trends in children’s heights and weights (Sinclair 1955). It is by no means certain, however, that the secular trends are wholly nutritional in origin. They may be due to out-breeding (Tanner 1955) or to other causes (Editorial 1961).