Energy requirements of pregnancy.

The energy requirements of pregnancy is a topic of considerable uncertainty because the apparent energy costs--to supply the energy required for the changes in maternal and fetal tissues and to cover the increase in basal metabolic rate (BMR), amounting to the equivalent of an extra 250-300 kcal/day--are rarely paralleled by actual findings. However, few studies have investigated this problem in a controlled longitudinal and statistically acceptable fashion. In this study, measurements of energy intake, BMR, body weight and fatness, physical activity, and mechanical efficiency of movement were made on 162 women in Scotland at 2- to 4-wk intervals throughout pregnancy, and data from 98 of these women were also obtained in the prepregnant state. Data from a parallel study in the Netherlands are also given. The gains in body weight, fatness, the fetal and placental weights, and the increase in BMR were all at the normal expected values. However, increases in energy intake were on the order of only 100 kcal/day during the second and third trimesters. Comparatively small reductions in physical activity, which would be difficult to measure precisely, are described that could account for the difference between actual energy intake and the energy costs of pregnancy.

The effect of 6 weeks of overfeeding on the body weight, body composition, and energy metabolism of young men.

The effect of overfeeding on the body weight, body fat, water content, energy expenditure, and digestibility of energy and nitrogen was investigated over 42 days in six young men. The metabolic rates in standard situations of work and rest were determined. Energy intakes were apparently increased by 6.2 MJ/day and energy expenditure fell slightly by 0.3 MG/day during overfeeding. Fecal and urinary losses of energy were a similar proportion of the gross energy intake in control and overfeeding periods (8%). Metabolizable energy intakes calculated from food tables agreed well with values derived from digestibility measurements in the control period (mean difference = +2%) but not in the overfeeding period (+8%). The implications of this are discussed. Mean body weight gain was 6.0 kg, 10% of initial weight; mean fat gain was 3.7 kg and water gain 1.8 liter. There were considerable interindividual differences in the weight and fat gain for a given excess energy intake. Metabolic rates in standard tasks were 10% higher at the end of overfeeding but expressed as kilojoules per kilogram per minute were similar to control values. Mean energy gain (144 MJ = fat gain X 39 kJ/g) was less than excess energy intake even allowing for overestimation of intakes using food tables and increases in metabolic rate. Such a discrepancy is unlikely to be due to unmeasured increases in metabolic rate but could have arisen from errors in the calculation of the variables involved. In this study where moderate weight gains were achieved by overfeeding mainly fat, increases in metabolic rate appear to be associated with increased body size and tissue gain rather than a luxuskonsumption mechanism.

Food intake, its relationship to body weight and age, and its apparent nutritional adequacy in New Guinean children.

Previous nutritional investigations in New Guinea have shown low intakes of protein and of energy yet the nutritional status of children and their ability to thrive have been regarded as better than could be expected. To investigate this apparent paradox, the dietary intakes of 482 New Guinean children, aged 1-18 years, living in two contrasting environments near the coast (Kaul) and in a highland region (Lufa) were determined by a weighed individual inventory method over 5-7 consecutive days. Body weights and skinfold thicknesses were lower than those of European children of comparable ages. These findings are to be reported and discussed more fully in a separate publication. Roots and tubers provided most of the energy and protein in the bulky, vegetable diets. The contribution of foods bought in local trade stores was higher than has previously been reported. Fat intakes were low, supplying 17% of the dietary energy in Kaul and 10% in Lufa. Protein intakes were similarly low, representing only 6% of dietary energy. The chemical scores of the protein calculated using the latest suggested amino acid scoring pattern (FAO/WHO, 1973) were high, 75-95. Using the previous pattern, these were 57-64. The adequacy of the energy and protein contents of individual diets was assessed using the FAO/WHO (1973) standards. An energy deficit was more common than a protein deficit. A considerable proportion of the children (42% in Kaul and 20% in Lufa) had dietary intakes which were apparently deficient in energy or protein, but this finding did not correspond to other signs of undernutrition. This suggests that current standards may still be set too high for some groups or that adaptations to suboptimal dietary intakes occur that are not disclosed by the usual techniques of assessing nutritional status.

The metabolic effects, and the composition of the tissue lost, in weight reduction by obese patients on treatment with fenfluramine.

1. Three groups of obese patients were treated for periods of up to 6 months. One group of 52 individuals received 80-120 mg fenfluramine daily. The second group of 20 people had placebo tablets. The third group of 28 patients were on a dietary restricted régime.2. Only the fenfluramine and dietary treated groups lost weight but there was no evidence of an increased metabolic rate after fenfluramine, either at rest or in standardized exercise. During the first month of treatment the mean weight loss in the group treated with fenfluramine was greater than that in the group treated by diet alone, but the difference was not significant (P<0.05). By the third month of treatment the mean weight loss was smaller in both groups, particularly in the women.3. The composition of the tissue lost in the weight reduction had a mean fat content of 75% and did not differ significantly between the fenfluramine group and the diet-restricted group, except in women.

Low body mass index, physical work capacity and physical activity levels.

In a normal population the distribution of body mass index (BMI) is such that a certain proportion of the population is likely to be at low values without necessarily being malnourished. However, although they may have low BMIs without being malnourished, they could certainly be physiologically and physically disadvantaged. An attempt is made to dissect out the probability of work capacity and physical activity being influenced by changes occurring in the human body with diminishing BMI. The conclusion reached is therefore that before physical activity is affected, the BMI would probably have to be 17 or less, although it is possible that work capacity might be reduced before this level is reached. In any case, work requiring the use of the body mass - such as carrying loads, digging or shovelling earth or coal, pulling or cycling a rickshaw, stone splitting etc.- would impose a greater stress on people of low BMI.

Low energy expenditures in free-living populations.

Low energy intakes are reported fairly frequently in populations where the implication is that these populations are free-living and that these intakes represent the norm. Intakes of energy, if they really reflect those pertaining to the average life-style, must also be reasonably indicative of energy expenditure. It is possible to define 'low' energy expenditure on the basis of obligatory metabolism (BMR + dietary induced thermogenesis) plus the energy needed for minimal physical activity--eg 2 h of standing activities and 1 h of walking daily. On that basis, the minimal realistic level is about 1.5 x BMR, and tables are given showing typical values for men and women over a range of body weights. If these values are accepted, considerable doubt must be placed on the interpretation of many reports in the literature of people apparently existing on 'low' energy intakes.

Changes in body composition in adolescent boys.

Changes in body composition were studied at age 10 and 13 years in 47 healthy school children of the Glasgow area. When seen at age 13, 22 had reached a total puberty rating (TPR) greater than 4 while the other 25 had a TPR less than 4. On relating body composition at age 10 with that observed at age 13 for the earlier maturing and later maturing boys it is clear that during this age period there are very fast and dynamic changes in body composition that can be characterized as a 'fat-wave' where children gain weight on a tissue that is almost 40 per cent fat, followed by the 'growth spurt' where they gain tissue that is almost 100 per cent lean mass while using up some of their body fat. Knowledge of this event is of importance for interpreting nutrition and body composition data in this age group especially when inter-social or inter-ethnic comparisons are being made. Some case observations suggest that the magnitude and direction of these changes in body composition can be influenced by environmental modulators, especially diet and physical activity.

Effect of meal frequency on the thermic effect of food in women.

The effect of meal frequency on the thermic effect of food (TEF), also referred to as dietary induced thermogenesis (DIT), was investigated in eighteen non-obese female subjects. Their metabolic rate before and after consuming the test meal was measured by open circuit indirect calorimetry using the Douglas bag technique, while the subjects were in the resting state (lying down). Eight subjects consumed a high carbohydrate-low fat (HCLF) meal providing 70, 19 and 11 per cent of the energy content from carbohydrate, fat and protein, respectively, and ten other subjects consumed a low carbohydrate-high fat (LCHF) meal providing 24, 65 and 11 per cent of the energy from carbohydrate, fat and protein, respectively. On two separate occasions, each subject consumed the appropriate diet either as one large meal containing 5040 kJ (1200 kcal) or as two smaller meals each containing 2520 kJ (600 kcal). TEF values were calculated for 6 h after the test meal and the mean values after consuming the HCLF meal were 377.0 +/- 30.0 kJ (90 +/- 7.2 kcal) and 381.0 +/- 26.5 kJ (91.0 +/- 6.3 kcal) for the one meal and the two meals, respectively. The mean TEF values for the subjects who consumed the LCHF meal wre 356.0 +/- 23.0 kJ (85.0 +/- 5.5 kcal) and 340 +/- 15.9 kJ (81.0 +/- 3.8 kcal) for the one meal and the two meals, respectively. No significant differences were found between the two feeding regimens (HCLF, P = 0.94; LCHF, P = 0.64) as well as between the compositions (P = 0.57). Thus, meal frequency and meal composition did not seem to influence the TEF.

Between-group differences in basal metabolic rates: an analysis of data collected in Scotland, the Gambia and Thailand.

Basal metabolic rate (BMR; using the Douglas bag method), body weight, and fat-free mass (FFM; using the skinfold method) were measured in 46 Scottish and 47 Gambian women in the non-pregnant non-lactating state and in 91 Scottish, 50 Gambian and 52 Thai women early in pregnancy. There were significant between-country differences in BMR (1) in absolute terms (MJ/d), (2) per kg body weight and (3) per kg FFM. However, these differences probably resulted from differences between the groups in average body weight and body composition. Differences per kg body weight were in part explained by differences in body fat content and the relatively low metabolic rate of adipose tissue. Differences in BMR/kg FFM were largely explained by between-group differences in the mass of the FFM, together with the finding that within each group, the BMR/kg FFM tended to decrease as weight increased. There were no significant differences in BMR between Scottish, Gambian and Thai women of similar FFM. There were, therefore, no apparent effects on BMR due to differences in race, climate, diet or nutritional status. Differences in the composition of the FFM could explain the 15 per cent lower BMR/kg FFM in the heaviest compared to the lightest subjects. This brings into question the widespread practice of using FFM as a metabolic reference standard. In contrast, BMR divided by the square root of FFM was similar in all three countries: for non-pregnant women, in MJ/kg0.5/d (mean and s.d.), Scotland 0.87 (0.07) and The Gambia 0.89 (0.07), and for pregnant women, Scotland 0.86 (0.07), The Gambia 0.87 (0.06) and Thailand 0.87 (0.08), and this may be a useful basis for comparing different groups in future. The accuracy of two equations for predicting BMR was assessed. The equation of FAO/WHO/UNU (1985) accurately predicted, from body weight, the average BMR of Scottish women, but under-estimated the average BMR of Gambian and Thai women by 5-10 per cent. The equation of Garby et al. (1988), which predicts BMR from FFM and fat mass, under-estimated the BMR of Scottish, Gambian and Thai women by 5, 10 and 14 per cent respectively, with the largest error within each group being for subjects with the smallest FFM.

A collaborative EEC study on seasonality and marginal nutrition: the Glasgow Hyderabad (S. India) Study.

As part of a collaborative project involving three European institutes and institutes in three developing countries, various measurements were made during an 18 month period of adaptations to seasonal food shortages. This study was carried out on a group of 102 economically poor adult women living in a large village near Hyderabad, S. India. These women not only looked after their households but also did agricultural work in the fields. A control group of 30 'middle-income' women were also studied; they did only limited work in the household and no work in the fields. Serial measurements (six in all, three in the harvest season and three in the lean season) were made of body weight, body fat, and various anthropometric variables. Comparisons were also made between these two seasons in food intake, BMR, activity levels and patterns, and a test of exercise capacity. There was a small loss in body weight and body fat (about 0.5 kg), and reductions in energy intake, BMR, and exercise capacity in the working women. No changes occurred in the control group of middle-income women. The nutritional stress imposed by the seasonal food shortage seemed relatively minor in degree, but did seem to induce some small adaptations.

Effects of an energy and micronutrient supplement on growth and development in undernourished children in Indonesia: methods.

OBJECTIVES: To describe the methodologies of a clinical trial on the effects of an energy and micronutrient supplement on the growth and development of undernourished children. DESIGN: This trial included two cohorts of children classified as nutritionally-at-risk who were randomly assigned to three treatments (condensed milk + micronutrients (E); skimmed milk + micronutrients (M); skimmed milk (S)). Supplements were given for a period up to 12 months. SETTING: Six tea plantations in Pangalengan, West Java were the site for this study. SUBJECTS: A 12-month-old (N=53) and an 18-month-old (N=83) cohort were recruited from 24 day-care-centers (DCC). Twenty children that received the S supplement were part of the 12- and 18 month-old cohort. Criteria for case inclusion were absence of chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. VARIABLES: Social variables included assessment of health facilities, childcare, housing, income and parental education. Nutrition and growth variables included dietary intake measured over a 24 hr period every 2 months; hemoglobin and three iron indicators measured at baseline, 6 and 12 months; anthropometry measured every 2 months and skeletal maturation measured every 6 months. Cognition and behavior included the assessment of mental and motor development and the behavior of the child under natural conditions. DATA ANALYSIS: An ANOVA was the statistic most frequently used to test inter-group differences and structural equation modeling was used to test the internal validity of the conceptual model of the study.

Effects of an energy and micronutrient supplement on growth and activity, correcting for non-supplemental sources of energy input in undernourished children in Indonesia.

OBJECTIVES: This paper investigates simultaneously the growth and activity of children that received an early energy and micronutrient supplement, adjusting for all non-supplemental energy intakes. Any additional change in growth and activity after this adjustment was then compared across supplements at three points felt to be representative of the study. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care-centers. Twenty children that received S belonged to the 12- and 18-month-old cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: Length was measured with a portable measuring board; a Detecto scale with an accuracy of 0.1 kg was used for the measurement of body weight. Arm and head circumferences were measured using similar fiberglass tapes. Motor activity was assessed through continuous 4 h observations at home and at day care centers. Anthropometry and activity were measured every two months over 12 months. RESULTS: After correcting for non-supplemental sources of energy intake, the effects of the supplement on weight and activity were observed at 2 months; effects on length and activity were observed at 6 months; and effects on weight alone were observed at 12 months.

Effects of an energy and micronutrient supplement on anthropometry in undernourished children in Indonesia.

OBJECTIVES: This paper reports the effects of early supplementary feeding on body weight, length, head circumference and arm circumference among the children in the Pangalengan study. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care centers. Twenty children that received S belonged to the 12- and 18-month cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: Length was measured with a portable measuring board; a Detecto scale with an accuracy of 0.1 kg was used for the measurement of body weight. Arm and head circumferences were measured using similar fiberglass tapes. RESULTS: Body weight showed effects on both cohorts at 2, 8 and 12 months; head circumference showed effects at 4 months in the 12-month-old cohort and at 10 months among the females of the 18-month-old cohort; and arm circumference showed effects across cohorts at 2, 8 and 12 months. In general the benefits are clearer for females and for the 12-month-old cohort.

A comparison of physical activity in Gambian and UK children aged 6-18 months.

The activity patterns of 81 Gambian and 53 UK children aged six, 12 or 18 months were compared by means of an activity diary technique. Major differences between communities were observed in the duration of play (2-3 times longer in UK compared to Gambian children) and in the duration of vigorous activities such as crawling, walking and running (2-4 times longer duration in the UK compared to the The Gambia). To investigate whether the lower activity of Gambian children could be explained by differences in nutritional or health status, subgroups of Gambian children were compared. Only small differences in activity pattern were found between Gambian children above and below 80% weight for age and between Gambian children who were or were not diagnosed ill within 10 days of study, suggesting that other factors (e.g. socio-cultural differences or the absence of conventional toys) may explain the lower activity of Gambian compared to UK children.

Nutritional intake of an undernourished infant population receiving an energy and micronutrient supplement in Indonesia.

OBJECTIVES: This paper reports the dietary intake (home, day care centers, supplement and breast milk) of the children in the clinical trial in Pangalengan. DESIGN: Two cohorts of children were randomly assigned to three treatments: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. SETTING: The sites were six tea plantations in Pangalengan, West Java. SUBJECTS: A 12-month-old (n = 53) and an 18-month-old (n = 83) cohort were recruited from day-care-centers. Twenty children who received S belong to the 12- and 18-month-old cohorts. Inclusion criteria were: no chronic disease; length-for-age < or = -1 standard deviation (s.d.) and weight-for-length between -1 and -2 s.d. of the median of the reference of the World Health Organization. METHODS: E = 1171 kJ + 12 mg iron; M = 209 kJ + 12 mg iron; S = 104 kJ. Supplementation was given for 12 months. Evaluations of intake were made at baseline and every 2 months thereafter. RESULTS: For the 12-month-old cohort the mean increase in daily energy intake approximately 2931 kJ for E, approximately 1675 kJ for M, and approximately 837 kJ increase over the 6 months for the S group. For the 18-month-old cohort the changes were approximately 2512 kJ for E approximately 1675 for the M group and approximately 1047 for the S group.