Food consumption of young stunted and non-stunted children in rural Zambia.

OBJECTIVE: The aim of this study was to assess the quality of diet of rural Zambian pre-school children, and to compare the dietary intake of stunted and non-stunted children. DESIGN: Cross-sectional study, in which dietary intake was assessed with a 24-h recall method. Height and weight were measured according to standard procedures. SETTING: Twelve villages in Samfya District, Zambia. SUBJECTS: Children aged 6-9 months ('infants') and 14-20 months ('toddlers'), attending Mother-and-Child Health Clinics, were eligible for study. Excluded were: 12 wasted, and 18 for other reasons. In total 106 infants and 99 toddlers were included. RESULTS: In infants and toddlers, total daily intake of energy, calcium, iron, and vitamin A was insufficient compared to recommended daily intakes. Only infants had insufficient protein intake. Compared to intake from weaning foods, breast milk was the main source of energy and most nutrients for infants. For toddlers, weaning foods were more important. Stunted infants and toddlers tended to have lower intakes of energy compared to non-stunted age-mates. Daily energy intake per kg bodyweight showed no difference between stunted and non-stunted children. CONCLUSIONS: Overall quality of weaning foods was inadequate. Stunted infants and toddlers showed a tendency of lower energy intakes compared to non-stunted age-mates.

Low-sodium diet in pregnancy: effects on blood pressure and maternal nutritional status.

In ninety-four Dutch nulliparous women the effects of a low-Na diet in pregnancy on blood pressure, energy and nutrient intake, Ca metabolism, Zn and Mg status and body composition were studied longitudinally. The women were randomly divided into an intervention group (n 41), which used a low-Na diet (mean urinary Na excretion 61 mmol/24 h) from week 14 of pregnancy until delivery and a control group (n 53; mean urinary Na excretion 142 mmol/24 h). No effect of the diet on blood pressure was observed. The use of a low-Na diet resulted in significantly reduced intakes of energy, protein, carbohydrates, fat, Ca, Zn, Mg, Fe and cholesterol. However, the women on the low-Na diet appeared to be able to adapt quite well to the reduced intake since Ca, Zn and Mg homeostasis was maintained. In the case of Ca and Mg this was probably due to the observed reduced urinary excretions of these nutrients. Non-significant reductions in weight gain (1.5 kg) and fat-mass gain (0.9 kg) over pregnancy were found in the women on the low-Na diet. No significant effects of the diet on birth weight or placental weight were observed.

No changes during pregnancy in the net cost of cycling exercise.

OBJECTIVE: To investigate whether work efficiency improves during pregnancy. DESIGN: Longitudinal; energy expenditure measurements (ventilated hood system) before the onset of pregnancy and in weeks 13, 24 and 35 of gestation. SUBJECTS: Healthy Dutch women (n = 26), recruited with advertisements in local newspapers and posters displayed in public buildings. MAIN OUTCOME MEASURES: Resting metabolic rate (RMR); metabolic rate during cycling at workloads of 30, 45, 60 and 75 W (CMRgross); post-cycling metabolic rate (PCMRgross); net energy costs of cycling (CMRnet = CMRgross - RMR); net recovery costs after cycling exercise (PCMRnet = PCMRgross - RMR). RESULTS: RMR, CMRgross and PCMRgross increased during pregnancy; under all conditions, metabolic rates were 0.9 kJ/min higher at 35 weeks gestation than before pregnancy (P < 0.05). CMRnet and PCMRnet showed no significant change during gestation. CONCLUSIONS: Changes in metabolic rate during cycling exercise suggest that pregnancy does not induce an improvement of work efficiency.

Energy balances of healthy Dutch women before and during pregnancy: limited scope for metabolic adaptations in pregnancy.

To investigate changes in energy metabolism during pregnancy, complete 8-d energy balances were measured before pregnancy and at 12, 23, and 34 wk gestation in 12 healthy Dutch women. While for each individual woman experimental diets were kept constant throughout the study with average intakes of 8.76 +/- 0.92 MJ/d (before pregnancy), 8.72 +/- 1.08 MJ/d (week 12), 8.85 +/- 0.93 MJ/d (week 23), and 8.72 +/- 1.12 MJ/d (week 34), neither the digestibility nor the metabolizability of the supplied diets showed significant changes from before pregnancy (92.8% and 88.6%, respectively) throughout pregnancy (92.7% and 88.2%, respectively). Twenty-four-hour energy expenditure (24-h EE) increased significantly from 8.63 +/- 0.80 MJ/d (before pregnancy) to 8.73 +/- 1.15, 9.08 +/- 1.08, and 9.94 +/- 0.94 MJ/d in weeks 12, 23, and 34 of gestation, to the extent predictable from changes in resting metabolic rate so that in an experimental setting with physical activity and energy intake standardized there seems little scope for other adaptive mechanisms.

No substantial reduction of the thermic effect of a meal during pregnancy in well-nourished Dutch women.

To investigate changes in the thermic effect of a meal (TEM) during pregnancy, metabolic rate was measured in the fasting state and during the first 180 min after consumption of a standardized test meal in twenty-seven women before, and in each trimester of pregnancy. Resting metabolic rate (RMR) showed a steady increase over pregnancy: values in weeks 24 and 35 of pregnancy were significantly higher than the prepregnancy baseline (Tukey's studentized range test). The pattern of changes of postprandial metabolic rate (PPMR) was similar to that of RMR. Consequently TEM, calculated as PPMR minus RMR, did not change over pregnancy; mean TEM values (kJ/180 min) before and in weeks 13, 24 and 35 of pregnancy were 117.3 (SD 19.4), 116.4 (SD 23.7), 111.6 (SD 24.4) and 111.5 (SD 26.7) respectively. We consider changes in TEM of less than 15% to be of little importance physiologically. If true changes in TEM over pregnancy are 15% or more we would have had a 90% chance of observing significant changes in TEM in the present study, given the number of subjects and the methods used. Therefore, we conclude that no substantial reduction in TEM occurs during pregnancy.

Effect of lactation on resting metabolic rate and on diet- and work-induced thermogenesis.

Energy metabolism was measured in 24 women before pregnancy and during lactation (2 mo postpartum). Resting metabolic rate (RMR) increased by 0.17 +/- 0.38 kJ/min and postprandial metabolic rate (PPMR) showed a similar increase (0.17 +/- 0.45 kJ/min). Thus, the thermic effect of the meal (PPMR minus RMR) was not affected by lactation. Between subjects, the lactation-induced increase in RMR appeared to be positively related to body weight. During lactation gross metabolic rates during cycling (CMR) were slightly reduced and net metabolic rates during cycling (CMR minus RMR) tended to decrease by 0.6 kJ/min at all workloads; however, the decrease was statistically significant only at the lowest workload. Changes in metabolic rate during the recovery period after exercise were not significant, but resembled changes in RMR rather than changes in CMR. We conclude that no major changes in metabolic efficiency occurred during lactation.