Energy requirements of children and adolescents

Total energy expenditure (TEE) was calculated at 1–18 years of age from measurements with doubly labelled water (DLW) in 483 boys and 646 girls, and heart rate monitoring (HRM) in 318 boys and 162 girls. Studies on obese, underweight and stunted groups were not included. TEE of populations with different lifestyles was estimated by factorial calculations in 42 studies on time allocation involving 1982 boys and 1969 girls in developed industrialised countries, and 1236 boys and 1116 girls in developing countries. Quadratic polynomial models were best to predict TEE in boys (TEE(MJ day−1) = 1.298 + 0.265 kg − 0.0011 kg2, r = 0.982, SEE = 0.518) and girls (TEE(MJ day−1) = 1.102 + 0.273 kg − 0.0019 kg2, r = 0.955, SEE = 0.650). TEE at 1–2 years was reduced by 7% based on DLW measurements and TEE estimates of infants. Energy requirements (ER) were calculated adding 8.6 kJ (2 kcal) for each gram of weight gained during growth. Compared with the 1985 FAO/WHO/UNU values1, ER were 18–20% lower from 1 to 7 years of age, 12% lower for boys and 5% lower for girls at 7–10 years, and 12% higher for either gender from 12 years onwards. Differences between industrialised and developing countries, the variance in DLW and HRM studies, and the standard error of the estimate (SEE) of the quadratic predictive equations, suggested that ER should be adjusted after 5 years of age by ±15% in populations with more or less physical activity than an average lifestyle. Physical activity recommendations must accompany dietary recommendations in order to maintain optimal health and reduce the risk of diseases associated with sedentary lifestyles.

Anthropometric predictors of body fat as measured by hydrostatic weighing in Guatemalan adults

BACKGROUND

Most predictive equations currently used to assess percentage body fat (%BF) were derived from persons in industrialized Western societies.

OBJECTIVE

We developed equations to predict %BF from anthropometric measurements in rural and urban Guatemalan adults.

DESIGN

Body density was measured in 123 women and 114 men by using hydrostatic weighing and simultaneous measurement of residual lung volume. Anthropometric measures included weight (in kg), height (in cm), 4 skinfold thicknesses [(STs) in mm], and 6 circumferences (in cm). Sex-specific multiple linear regression models were developed with %BF as the dependent variable and age, residence (rural or urban), and all anthropometric measures as independent variables (the "full" model). A "simplified" model was developed by using age, residence, weight, height, and arm, abdominal, and calf circumferences as independent variables.

RESULTS

The preferred full models were %BF = -80.261 - (weight x 0.623) + (height x 0.214) + (tricipital ST x 0.379) + (abdominal ST x 0.202) + (abdominal circumference x 0.940) + (thigh circumference x 0.316); root mean square error (RMSE) = 3.0; and pure error (PE) = 3.4 for men and %BF = -15.471 + (tricipital ST x 0.332) + (subscapular ST x 0.154) + (abdominal ST x 0.119) + (hip circumference x 0.356); RMSE = 2.4; and PE = 2.9 for women. The preferred simplified models were %BF = -48.472 - (weight x 0.257) + (abdominal circumference x 0.989); RMSE = 3.8; and PE = 3.7 for men and %BF = 19.420 + (weight x 0.385) - (height x 0.215) + (abdominal circumference x 0.265); RMSE = 3.5; and PE = 3.5 for women.

CONCLUSION

These equations performed better in this developing-country population than did previously published equations.

Cardiovascular disease risk factors are related to adult adiposity but not birth weight in young guatemalan adults

Fetal undernutrition has been hypothesized to program inappropriate metabolic responses to nutritional abundance in later life. Most studies have been conducted in industrialized countries. We studied the relationship between birth weight and risk factors for cardiovascular disease (CVD) among 187 men and 198 women age 20-29 y (mean age 24 y) who had participated in a longitudinal study conducted in Guatemala between 1969 and 1977. In women, birth weight was positively associated with adult body mass index (BMI; P < 0.01), systolic (P < 0.001) and diastolic blood pressure (P < 0.05), but not with glucose or any lipid measure. In men, birth weight was not associated with adult BMI, blood pressure or glucose, and was weakly and inversely related to total cholesterol and LDL cholesterol (test for trend: P = 0.06 and P = 0.09, respectively). Adult BMI was associated with increased prevalence of CVD risk factors in both men and women. Our data offer no support for the fetal programming of cardiovascular disease risk hypothesis in young adult women, and weak support in young adult men. Overweight in adults is a strong determinant of variance in CVD risk factor prevalence.

Determinants of fasting glucose in young Guatemalan adults

OBJECTIVE

To examine correlates of fasting glucose, a precursor for type 2 diabetes mellitus, in young adults in Guatemala, a country undergoing an epidemiologic transition.

DESIGN

Cross-sectional.

METHODS

Anthropometric, lifestyle, dietary, serum lipid, and socioeconomic characteristic data were collected on 189 men and 201 women (mean age 24.4 years) born in four villages in Eastern Guatemala. We used linear regression to identify parsimonious predictive models, including 2-way interactions.

RESULTS

In men, mean fasting glucose was 87.3 mg/dL (SD 10.2); our model explained 30% of variance. Body mass index (BMI), abdomen-to-hip ratio (AHR), and total cholesterol showed graded positive effects. BMI and AHR interacted (P<.001); men with high BMI and high AHR had the highest fasting glucose levels. No dietary factors independently predicted fasting glucose. In women, mean fasting glucose was 83.9 mg/dL (SD 8.5); 22% of variance was explained by BMI, energy-adjusted fat intake, physical activity, birth village, and current residence (rural/urban). BMI and fasting glucose were positively related. Urban residence interacted with birth village (P=.06) and physical activity (P=.13).

CONCLUSIONS

The major conclusion drawn from this study is that increased adiposity, even among lean individuals, is the largest environmental predictor of fasting glucose. Prevention and control of obesity in young adults in transitioning countries are key strategies for the prevention of diabetes.

Rural-to-urban migration and cardiovascular disease risk factors in young Guatemalan adults

BACKGROUND

Migration to cities may increase cardiovascular disease risk factors in developing countries. We examined rural and urban individuals who were born in the same villages and shared similar childhood experiences.

METHODS

Blood lipids and glucose, blood pressure, anthropometry, body composition, physical activity, and food, tobacco and alcohol consumption were examined in 161 men and 193 women, 19-29 years old, living in their village of birth (76 commuted to work in Guatemala City), and in 76 men and 43 women living in the city.

RESULTS

Rural and urban women had similar prevalence of overweight (28%), elevated body fat (29.8 +/- 6.1%) and low physical activity (83%). Compared to rural men, more urban men were sedentary (79 versus 27%), and they had higher body fat (15.3 +/- 5.3% versus 13.3 +/- 5.7%), serum cholesterol (4.27 +/- 0.75 versus 3.90 +/- 0.70 mmol/l [165 +/- 29 versus 151 +/- 27 mg/dl]), low density lipoprotein [LDL]-cholesterol (2.66 +/- 0.72 versus 2.30 +/- 0.62 mmol/l [103 +/- 28 versus 89 +/- 24 mg/dl]) and total cholesterol/high density lipoprotein [HDL]-cholesterol ratio (4.6 +/- 1.0 versus 4.1 +/- 0.9). Commuters showed intermediate values. Women had higher serum cholesterol (4.43 +/- 0.80 mmol/l [171 +/- 31 mg/dl]) than men in rural and urban areas. Urban residents ate/drank more saturated fats, red meat and sweetened beverages, and less legumes.

CONCLUSIONS

High proportions of young Guatemalan women were overweight and sedentary. Migration to a city increased sedentarism and undesirable eating habits among men and women; men became fatter and their lipid profile worsened. Public health actions must address the prevention of emerging chronic diseases in countries still burdened by undernutrition and infections.

Physical activity, genetic, and nutritional considerations in childhood weight management

Almost one-quarter of U.S. children are now obese, a dramatic increase of over 20% in the past decade. It is intriguing that the increase in prevalence has been occurring while overall fat consumption has been declining. Body mass and composition are influenced by genetic factors, but the actual heritability of juvenile obesity is not known. A low physical activity (PA) is characteristic of obese children and adolescents, and it may be one cause of juvenile obesity. There is little evidence, however, that overall energy expenditure is low among the obese. There is a strong association between the prevalence of obesity and the extent of TV viewing. Enhanced PA can reduce body fat and blood pressure and improve lipoprotein profile in obese individuals. Its effect on body composition, however, is slower than with low-calorie diets. The three main dietary approaches are: protein sparing modified fast, balanced hypocaloric diets, and comprehensive behavioral lifestyle programs. To achieve long-standing control of overweight, one should combine changes in eating and activity patterns, using behavior modification techniques. However, the onus is also on society to reduce incentives for a sedentary lifestyle and over-consumption of food. To address the key issues related to childhood weight management, the American College of Sports Medicine convened a Scientific Roundtable in Indianapolis.

Influence of exercise on linear growth

The effects of exercise on linear growth were investigated in malnourished rats and in preschool children recovering from protein-energy malnutrition (PEM). Physical activity was either restricted or forced upon weanling rats that were pair-fed with 73 or 49% of the food eaten ad libitum by rats of the same age. Physically active animals grew more in length and weight than their inactive counterparts. In a subsequent study, 20 children, 24-48 months old, under treatment for severe PEM, were assigned to either an Active group (stimulated, but not forced, to participate in games and activities that involved walking uphill, climbing a ramp, running, tumbling and climbing stairs) or a Control group (with the ad libitum pattern of physical activity and rest commonly observed in child-care and nutrition rehabilitation centers). Dietary intake was controlled and almost identical in both groups (2.5 +/- 0.07 g protein and 117 +/- 7 kcal/kg/day). Mean energy expenditure during daytime, assessed by heart rate monitoring and its relationship with oxygen consumption, were 2.0 and 1.7 times basal metabolic rate in the Active and Control groups, respectively (P < 0.01). In 6 weeks, both groups gained an average of 1.98 kg. However, the Active group grew more in length (22 +/- 8 vs 14 +/- 6 mm, P < 0.05) and lean body mass (final creatinine-height index: 0.97 +/- 0.12 vs 0.89 +/- 0.09, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Oral gentamicin is not effective treatment for persistent diarrhea

We conducted a randomized, double-blind, placebo controlled clinical trial of oral gentamicin (10 milligrams/kilogram body weight/day for five days) in treatment of unselected cases of persistent diarrhea (duration 14-18 days at initiation of treatment) among 3-36-month-old children in a rural Guatemalan community. Following random assignment of each child to a treatment group, the appropriate dose of gentamicin or placebo was administered to the child three times daily by a study nurse; this nurse also identified the presence or absence of diarrhea on each day of treatment and for the next two days. Cure was defined as cessation of diarrhea during the five-day treatment period, sustained through at least the two days after completion of treatment. Among 92 evaluable cases who entered the clinical trial, there was essentially no difference in cure rate between gentamicin and placebo treatment groups (42% versus 43%). Enteroadherent strains of Escherichia coli were identified in 46% of children tested in this trial; no significant difference existed between treatment groups in frequency of isolation of this or any other enteropathogen. Among 40 children having successful duodenal cultures immediately prior to beginning treatment, > or = 10(4) aerobic organisms per milliliter of fluid were identified in 12 (30%); treatment groups did not differ substantially with respect to proportion of children identified with this level of duodenal microbial colonization. Failure of gentamicin treatment did not appear to be explained by emergence of resistance, although a small number of resistant enteropathogens were identified near the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption of carbon 13-labeled rice in milk by infants during acute gastroenteritis

To determine whether rice cereal could be used to complement a cow milk-based diet in the nutritional management of infants with acute diarrhea, we assessed its digestion and absorption in eight affected male infants, 69 to 131 days of age. They received cow milk formula with 5.4% lactose (diluted 1:1 with water and precooked rice cereal) 5 to 22 hours after admission and rehydration. The first feeding consisted of milk diluted with carbon 13-enriched rice cereal. A 48-hour fecal collection and balance study was performed. Rice cereal was reasonably well absorbed (84.0% to 95.8%) by seven of the eight infants. The study was repeated in seven of the infants after they had recovered. Our results indicated that rice cereal is well absorbed by young infants with acute diarrhea and that it is an adequate nutrient supplement for this patient population.

Effects of nutritional recuperation on E-rosetting lymphocytes and in vitro response to thymosin in malnourished children

The percentage of peripheral blood lymphocytes forming rosettes with sheep erythrocytes (E-rosettes) was determined at admission to the INCAP Clinical Center in eight acutely malnourished Guatemalan children, and again after 14 and 28-30 days of nutritional therapy. While the mean percentage of E-rosettes increased during therapy, the change (from 35.6 +/- 10% to 43.3 +/- 19%) did not reach statistical significance because of the variable response of different subjects. At each time period, however, in vitro incubation with the thymic factor, thymosin fraction 5, significantly increased the percentage of E-rosetting lymphocytes. The presence of thymosin responsive cells in circulation after 1 month of optimal nutritional support indicates that immature T-lymphocytes can persist in circulation in patients with severe malnutrition, even after clinical improvement. Thus, neither the percentage of E-rosettes in peripheral blood nor their response to in vitro incubation with thymosin correlated with anthropometric measures of nutritional status in individual patients. This suggests that other nutritional or nonnutritional factors may be important modulating influences on T-lymphocytes, and that prospective studies with thymic factor administration are warranted.

Immature circulating lymphocytes in severely malnourished Guatemalan children

The percentage of peripheral blood lymphocytes forming rosettes with sheep erythrocytes (E-rosettes) was determined in 33 severely malnourished Guatemalan children, and in two groups of clinically well but mildly growth retarded children from the same environment. Mean E-rosettes in the acutely ill patients was lower than the value observed in the mildly malnourished children, although there was considerable overlap between groups. These data differ from previously published studies of severely malnourished children from other parts of the world in that not all patients had decreased values for E-rosettes, in contrast to the uniform depression reported by others. As all patients were clinically similar, the results suggest that there may be specific nutrient defects associated with protein-energy malnutrition that particularly affect immune function. In addition, in vitro incubation of lymphocytes from the acutely malnourished children with the thymic factor, thymosin fraction 5, increased the percentage of E-rosettes in a dose-dependent fashion. These data suggest that immature, thymosin-responsive T cells are present in circulation. It is possible that in vivo thymosin administration may be beneficial for malnourished individuals.

Calcium metabolism in children recovering from severe protein-energy malnutrition

Twenty preschool children with severe edematous protein-energy malnutrition (PEM) were studied during the first 45 days of recovery. All children received 4 g/kg/day of protein and 150 kcal/kg/day of energy from a milk-based recovery formula, providing 130-140 mg/kg/day of calcium (Ca). Children were randomized to two treatment groups, one receiving intact milk formula and the other a lactose-free preparation. Both groups showed a high efficiency of intestinal calcium absorption, sustained even after the normalization of weight for height and lean body mass. The presence or absence of lactose in the diet did not affect intestinal calcium absorption, and increased stool volume in the early period of recovery in the children receiving intact milk was not associated with higher fecal Ca losses. Urinary Ca excretion was within the range reported for healthy children under a normal diet. These results suggest that therapeutic amounts of calcium should be delivered to children with PEM well beyond the normalization of body weight and lean body mass.

Absorption of selenium from milk protein and isolated soy protein formulas in preschool children: studies using stable isotope tracer 74Se

Absorption of selenium as the stable isotopic tracer [74Se]selenite was measured in four preschool children who were receiving liquid formula diets based on casein, isolated soy protein, and a 50:50 combination of the two protein sources. The children were in continuous ambulatory balance studies within the Clinical Research Center during three consecutive 11-day collection periods. The enrichment of the 74Se/76Se ratio in feces was measured by radiochemical neutron activation analysis, with fractional absorption estimated therefrom. Mean fractional absorption of selenium (+/- SD) from the formulas based on milk, isolated soy protein, and milk-soy were 64.2 +/- 14.6, 73.4 +/- 19.0, and 45.0 +/- 10.9%, respectively, with the combined formula having a significantly lower intestinal uptake for added selenite than the casein formula. Stable isotopes of selenium are safe and potentially useful tools for examining its bioavailability in the diets of young children.

Dietary manipulation of postprandial colonic lactose fermentation: II. Addition of exogenous, microbial beta-galactosidases at mealtime

The feasibility and efficacy of adding microbial beta-galactosidase enzymes directly to milk at the time of consumption was explored in adult lactose-malabsorbers. The hydrogen breath test, and on one occasion, the rise in blood glucose, were used as indices of the completeness of intraintestinal hydrolysis and absorption of milk lactose. When added to 360 ml of cow milk containing 18 g of lactose, empirical dosages of three beta-galactosidases--one from Kluyveromyces (yeast) and two from Aspergillus (fungal)--had some effectiveness in reducing postprandial H2 excretion, although no in vivo treatment at the dosages chosen was as effective as pre-incubation of the milk in vitro. The yeast enzyme also reduced symptom frequency as compared to intact milk and enhanced postprandial rises in blood glucose. The replacement therapy with exogenous, food-grade beta-galactosidases may provide a useful intervention to reduce lactose malabsorption and milk intolerance in individuals with primary lactase deficiency.

Effective in vivo hydrolysis of milk lactose by beta-galactosidases in the presence of solid foods

The feasibility of enzyme replacement therapy with exogenous, food-grade, microbial enzymes at mealtime to effect intragastrointestinal hydrolysis of the lactose from 360 ml of cow's milk consumed with a solid food meal (breakfast cereals) was investigated in adult Guatemalan lactose-malabsorbers using a hydrogen breath-analysis procedure to quantify the completeness of postprandial carbohydrate absorption. Adding 2 g of a commercial preparation of beta-galactosidase from Kluyveromyces lactis at mealtime to milk taken with a refined cereal (cornflakes) and an unrefined cereal (bran) reduced the production of excess breath H2 attributable to lactose maldigestion to a level not significantly different from that achieved with lactose-prehydrolyzed milk. Sucrase, as expected, had no effect on H2 production. A beta-galactosidase from Aspergillus niger was less effective that the K. lactis enzyme for in vivo hydrolysis. Thus, exogenous betagalactosidases can eliminate lactose malabsorption in lactase-deficient individuals even in the presence of solid foods, allowing lactose intolerant persons to consume milk and dairy products without gastrointestinal discomfort.

Dietary manipulation of postprandial colonic lactose fermentation: I. Effect of solid foods in a meal

The effect of adding solid foods--cornflakes, banana and hard-boiled egg--to a meal with 360 ml of intact milk containing 18 g of lactose was investigated in 13 lactose-malabsorbers and 10 lactose-absorbers chosen from 36 Guatemalan adults screened for their capacity to digest and absorb completely the lactose in this volume of milk. A six-hour hydrogen breath test was used as the index of carbohydrate absorption. Minimal breath H2 was excreted by lactose-absorbers with either the intact milk alone, the intact milk with solid foods, or lactose-prehydrolyzed milk with solids. In lactose-malabsorbers, however, the 6-h excretion of H2 with intact milk plus solid food was intermediary between milk alone and prehydrolyzed milk with solids. A relative net reduction of 47% in lactose malabsorption was produced by adding food, and the peak-rise in breath H2 was delayed by 2 hours. A physiological consequence of taking solid foods along with milk is a slower rate of colonic fermentation, and this may be the basis for reducing gastro-intestinal symptoms in lactose-intolerant malabsorbers.

The effect of dietary lactose on the early recovery from protein-energy malnutrition. I. Clinical and anthropometric indices

To assess the advisability of using lactose-containing formulas in the rehabilitation of severely malnourished children, indices of clinical recovery, growth and restoration of body proteins and gastrointestinal function were measured longitudinally during the initial 45 days of hospitalization in 20 male, preschool children with kwashiorkor and marasmic-kwashiorkor. All patients received a diet based on cows' milk, but half were allocated to a formula pretreated with beta-galactosidase to hydrolyze the lactose, while the others received the untreated, intact milk. The groups were identical with respect to clinical criteria on admission. For the final 37 days of the protocol, the subjects received 4 g of protein and 150 kcal of energy per kg per day. More diarrhea was experienced by the intact lactose group during early hospitalization. Overall, recovery was satisfactory in both cohorts, and there were no differences in rates of growth, body protein repletion, restoration of energy reserves nor intestinal functions. In conclusion, the routine reduction of lactose content from a milk-based diet for severe protein-energy malnutrition offers no advantages.

The effect of dietary lactose on the early recovery from protein-energy malnutrition. II. Indices of nutrient absorption

Absorption of dietary energy, nitrogen, carbohydrates and calcium, and retention of nitrogen and calcium were studied in 20 children with protein-energy malnutrition of the edematous type, using metabolic balance techniques and breath H2 analysis, to assess the advisability of using lactose-containing formulas in the rehabilitation of severely malnourished children. Ten patients received for 45 days a diet formula based on cows' milk (intact milk) and 10 similar children received the same formula pretreated with beta-galactosidase to hydrolyze the lactose (hydrolyzed milk). Dietary intakes were gradually increased to reach, on the 8th day, 4 g of protein and 150 kcal/kg. There were no differences between groups with respect to absorption or retention of the index nutrients. Postprandial carbohydrate malabsorption was occasionally observed in two patients with servings of the intact milk formula, and in one with the hydrolyzed milk diet. When the nutritional quality of a diet is assessed, the amount of nutrients that are absorbed and utilized are more important than the small, incompletely absorbed fractions that do not have significant metabolic or clinical implications. Therefore, the use of milk as the protein source for recovery diets is not contraindicated in the routine treatment of PEM.

Soybean protein in human nutrition: an overview

The nutritional value of processed soy protein in human protein nutrition is reviewed on the basis of growth, nitrogen balance and metabolic studies in infants, children, adolescents and adults. When well processed soy products serve as the major or sole source of the protein intake, their protein value approaches or equals that of foods of animal origin, and they are fully capable of meeting the long term essential amino acid and protein needs of children and adults. The significance of the sulfur amino acid content of soy protein for practical human nutrition is also examined. For young children and adults, under conditions of normal usage of soy protein, it is concluded that methionine supplementation of good quality products is unnecessary and possibly undesirable. For feeding of the newborn, the limited data available suggest that supplementation of soy‐based formulas with methionine may be beneficial. However, the appropriate level of supplementation is considerably less than that suggested from results obtained in rat feeding studies. At total protein intakes that approximate current dietary protein allowances, well processed soy protein products can replace meat and fish proteins without reducing the utilization of dietary nitrogen in adults, and they can serve as nutritionally valuable protein sources in cereal‐based diets for child feeding. The value of long term studies concerned with tolerance to and acceptability of new soy protein products in adults is emphasized, and favorable results with two isolated soy protein products are described. The data indicate that properly processed soy protein foods are well tolerated and of good protein value for humans of all ages.

Calcitonin treatment in hereditary bone dysplasia with hyperphosphatasemia: a radiographic and histologic study of bone

Two children with bone dysplasia with hyperphosphatasemia (juvenile Paget's disease) were treated with synthetic human calcitonin. The progress of bone disease was monitored radiographically and histologically. Pretreatment radiographs showed markedly abnormal bone, characterized by lack of discrete cortex and absence of normal modeling. During treatment a discrete cortex was formed composed of compact bone, and more normal modeling occurred. This coincided with a histologic change from woven bone before treatment to a more lamellar type during treatment.

Hereditary bone dysplasia with hyperphosphatasaemia: response to synthetic human calcitonin

Four cases of familial bone dysplasia with hyperphosphatasaemia were treated with synthetic human calcitonin. Prior to therapy, all four cases were characterized by marked bone deformity, pain, tenderness and elevated levels of serum alkaline phosphatase and urinary hydroxyproline. Treatment with calcitonin produced in each case a striking clinical, biochemical and radiographic remission. Pain and tenderness was greatly diminished and urinary hydroxyproline and serum alkaline phosphatase levels were significantly decreased. Radiographic regression of the bony abnormalities was apparent as early as 4 1/2 months after the start of treatment. Prior to therapy bones exhibit no real organization. After calcitonin treatment, the radiographic appearance of a normal cortex and medullary cavity was clearly evident for the first time.