P. R. Payne

Comparative nutrition in pregnancy and lactation

Allison, J. B. (195 j). Physiol. Rev. 35, 664. Berg, B. N. & Sims, H. S. (1961). J . Nutr. 74, 23. Blaxter, K. L. & Wood, W. A. (1952). Br.J. Nutr . 6, 56. Bourlibre, F. (1957). The Biology of Ageing. Symposia of the Institute of Biology 6, 27. Brody, S. (1945). Bioenergetics and Growth. Kew York: Hafner Publishing Co. Inc. Brody, S. & Procter, R. C. (1932). Res. Bull. Mn. agric. Exp. S t n no. 116. Ciba (19j9). Ciba F d n Colloq. Ageing. Vol. 5 . Comfort, A. (1961). Scient. Am. 205, no. 2, p. 108. FA0 (1957). F.A.V. nutr. Stud. no. 16. F A 0 (1965). F.A.V. nutr. Stud. no. 301. Flower, S. (1931). Proc. zool. Soc. Lond. p. 145. Hawkins, A. E. & Jewell, P. A. (1962). Proc. zool. SOC. Lond. 138, 137. Hawley, E. E., Murlin, J. R., Nasset, E. S. & Szymanski, T. A. (1948). J . Nutr. 36, 153. Irving, L. (1966). Scient. Am. 214, no. I, p. 94. Kleiber, M. (1947). Physiol. Rev. 27, 51 I. Kon, S. K. (1928). L3iochern.J. 22, 261. McCay, C. M., Crowell, M. F. & Maynard, L. A. (1935). J. Nutr. 10, 63. Miller, D. S. (1963). Publs natn. Res. Coun., Wash. no. 1100, p. 34. Miller, D. S. & Bcnder, A. E. (1955). BY. J. Nut?. 9, 382. Miller, D. S. & Payne, P. R. (1963). J. theor. Bid. 5, 1398. Miller, D. S. & Payne, P. R. (1964). Proc. Nutr . SOC. 23, 11. Miller, D. S. & Paync, P. R. (1968). J. exp. Geront. 3, 231. Minot, C. S. (1889). J. PhySiol., Lond. 12, 97. Mitchell, H. €1. (1964). Comparative Nzitritton of Man and Domestic Animals. Vol. 2. New York: Academic Press, Inc. Needham, J, (1941). Time the Refreshing Riwer. London: Allen & Unwin. Rubner, M. (1908). Dus Problem der Lebensdmrw und seine Beziehungen zzi Wuchstiim und Erniihrung.

A model for the prediction of energy balance and body weight

A model for changes in energy balance and body weight is described which can be written as an iterative computer program. Medium and long-term changes in body weight resulting from random daily fluctuations in energy balance are quantitatively predicted. Body weight varies periodically about a mean value to to the extent of +/- 1 kg over a span of a few weeks. Long-term weight stabilization is the result of a dynamic equilibrium between energy intake and output which depends on activity and tissue metabolism. A lean : fat tissue deposition ratio defines the metabolic type of individual. This ration, which is constant for each individual, governs the proportions in which these tissues are both deposited and mobilized. In the model, the ratio has an important effect on the magnitude and composition of the weight gains resulting from over-eating. It is suggested that the differences in response which have been observed in over-eating experiments result from inter-individual differences in this ratio.

MECHANISMS FOR THE CONTROL OF BODY-WEIGHT

Various hypotheses for the mechanism of regulation of body-weight in human adults have been proposed in the light of the magnitude of the long-term changes in weight actually observed. One of these hypotheses has been represented in the form of a computer simulation model which has been used to demonstrate that (i) it is not necessary to postulate the existence of a set-point regulatory system, and (ii) in practice, several mechanisms, including hunger and satiety, the relative constancy of habits and customs of behaviour, and the existence of cognitive thresholds combined with a relatively simple physiological negative feedback system probably constitute the simplest hypothesis for the mechanism of weight stability.

Pattern of development of bone in childhood and adolescence.

Abstract Data are presented on the growth in length and cortical area of the 2nd metacarpal in children aged 2-18 years, derived from radiographs of the files of the Harpenden growth study. These results supplement those previously reported for adults and are in good alignment with them. Combined percentile curves have been produced which can be used to assess the amount of cortical bone in children and adults, by calculation of a simple ratio representing bone cortical area to surface area. The form of the curves for cortical area is very similar to that of the 50th weight-for-age percentile, in boys and in girls. The ratio of cortical area to body-weight can be calculated for each age-group, and by the age of 18 this ratio is approximately 20% lower in girls than boys. The relatively lower bone-mass in girls in early adult life may be one of the factors leading to the higher incidence of osteoporosis in women in old age.

Environmental Conditions and Body Temperatures of Elderly Women Living Alone or in Local Authority Home

The environmental and body temperatures of two groups of elderly women have been measured. One group was living in a local authority home (L.A.H.) and the others in their own homes in North London. The L.A.H. provided a constant environmental temperature which was at all times higher than that of the private houses. In the latter group the ambient temperature was higher in bed-sitting rooms than in houses with separate living rooms and bedrooms. Body temperatures in summer were similar throughout both groups. In winter the skin and mouth temperatures of the subjects living independently were lower than those in the L.A.H. Four subjects who had low mouth temperatures measured during two consecutive winters did not prove to have lowered deep body temperatures. The diet of these four subjects was similar in respect of all nutrients to that found in other groups of subjects of the same age, and in relation to published dietary standards was adequate in all respects.

A model of seasonal changes in energy balance

In developing countries, many peasant farmers experience regular seasonal changes of body weight, so that the adequacy of food energy supply cannnot be assessed simply in terms of energy balance and a desirable body weight. A computer simulation model has been devised, which predicts the pattern of changes in body weight which result from the annual cycle of agricultural work load, and the way in which food consumption is regulated over the year. The model also includes the effect of post‐harvest storage losses. The actual observed patterns of food use of farmers in The Gambia, and in Burma, are first of all used to simulate the seasonal changes in body weight and these agree well with observations. The effects of alternative strategies of food use are then tried, ranging from a constant intake throughout the year, to an exaggerated feasting and fasting cycle. The simulations show that the actual food allocation patterns adopted by these two peasant populations constitute an optimum strategy in which the ...

Nutritional status indicators : Interpretation and policy making role

Anthropometric measurements, usually based on the growth of children, and considered to be reflective of the degree and state of nutritional status, have long been the measurement of choice in assessing the health and welfare of a community. However, it must be borne in mind that any such measure serves only as an indicator of the functioning of a very complex system. As such it is subject to error when applied according to rigid and predetermined numeral scales reflecting social valuations, and really cannot be considered to be a technical description of a physiological state. The limitations to the application of such inferred nutritional data, from a systems viewpoint, are many and should be recognized. Nonetheless, measures of nutritional status can provide valuable information on the effects of the health, social and food environment of individuals and communities. Bearing in mind the limitations of their usefulness, such measurements can serve as useful tools in policy making and can be integrated with information from other sectors of government for this purpose.

Socio-economic and seasonal patterns of adult energy nutrition in a South indian village

Energy intake, weight, height, body fat and physical activity pattern of 296 men and 371 women in a rural S. Indian village were measured at four seasons of one year. Enegy intake values were consistent with the low body size but high levels of physical activity observed in both sexes. Socio‐economic status, defined by household land holding, had highly significant influences on energy intake, body weight and body fat content in both sexes. Seasonal patterns of energy intake and physical activity were more marked in women than in men, but there were no significant seasonal differences in body weight or body fat content in either sex. There was no significant interaction between socio‐economic and seasonal influences on energy nutrition. The lack of seasonal variation in body energy stores probably reflects the impact of recent irrigation on patterns of agricultural and economic activity in this area.

Relationship between tissue mobilization and storage in the rat

The amount of energy mobilized or stored as protein, expressed as a proportion of the total energy stored or mobilized (defined as the P ratio, Payne & Dugdale, 1977), was investigated in the young male (rapid growth) and adult female (slow growth) rat. Energy mobilization was induced by a 3 d fast and the changes in body content of fat and lean tissues were used to estimate the fasting P ratio (Pfast). Tissue storage was subsequently effected by 17 d of refeeding and the corresponding ratio (P(refed)) was calculated from the amounts of lean and fat tissue regained. The same experimental protocol was used for measuring Pfast and P(refed) in weanling (30 d) and adult (130 d) rats. Weight-matched individuals were assigned to three groups. All animals in group 1 were killed at the beginning of the experiment. Animals in group 2 were fasted for 3 d and then killed. Group 3 animals were first fasted for 3 d, then had free access to a stock diet for a further 17 d before being killed. During fasting, a close linear relationship was found between weight change and body energy changes (r 0.985, and r 0.92, P < 0.001 for weanlings and adult rats respectively) and between carcass N loss and urinary N loss (r 0.933, P < 0.001). These relationships were used to estimate the body energy and N content of each animal at the end of the initial fasting period. Hence, both Pfast and P(refed) values could be calculated for all individuals at both ages. When Pfast and P(refed) were calculated for adult rats, the mean values were similar (0.138 (SE 0.002) and 0.130 (SE 0.006) respectively). Individually, the Pfast and P(refed) values were correlated (r 0.54, P = 0.058). In weanling rats, the mean P(refed) value was about 2.5 times the Pfast (0.421 (SE 0.0113) v. 0.156 (SE 0.004)). Despite the differences in Pfast and p(refed), the individual values were again correlated (r 0.668, P < 0.05). These results support the suggestion made by Payne & Dugdale (1977), that particular P. ratio values are characteristic of individuals and describe the extent to which protein is mobilized or stored during fasting or refeeding. These observations are discussed in relations to the predictions made by the Payne-Dugdale model.

Nutrition planning and food policy

Abstract The development priorities of recent years may be a cause of malnutrition amongst the poorest groups. To achieve more adequate planning, elements of an interdisciplinary approach are suggested in this article. These could be characterised as identification of risk groups, analysis of consumption patterns, continued monitoring, and understanding of the effects on individual behaviour of social, cultural, educational and economic forces.