Diet and insulinlike growth factor I in relation to body composition in women with exercise-induced hypothalamic amenorrhea.

To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise.     

Effects of resistance or aerobic exercise training on total and regional body composition in sedentary overweight middle-aged adults

The purpose of this study was to examine the effects of 10 weeks of aerobic endurance training (AET), resistance exercise training (RET), or a control (CON) condition on absolute and relative fat mass (FM) or fat-free mass (FFM) in the total body (TB) and regions of interest (ROIs) of sedentary overweight middle-aged males and females. Following prescreening, 102 subjects underwent anthropometric measurements, dual-energy X-ray absorptiometry, and strength and aerobic exercise testing. Randomized subjects (male RET, n = 16; female RET, n = 19; male AET, n = 16; and female AET, n = 25) completed supervised and periodized exercise programs (AET, 30-50 min cycling at 70%-75% maximal heart rate; RET, 2-4 sets × 8-10 repetitions of 5-7 exercises at 70%-75% 1 repetition maximum) or a nonexercising control condition (male CON, n = 13 and female CON, n = 13). Changes in absolute and relative TB-FM and TB-FFM and ROI-FM and ROI-FFM were determined. At baseline, and although matched for age and body mass index, males had greater strength, aerobic fitness, body mass, absolute and relative TB-FFM and ROI-FFM, but reduced absolute and relative TB-FM and ROI-FM, compared with females (p < 0.05). After training, both female exercise groups showed equivalent or greater relative improvements in strength and aerobic fitness than did the male exercise groups (p < 0.05); however, the male exercise groups increased TB-FFM and reduced TB-FM more than did the female exercise groups (p < 0.05). Male AET altered absolute FM more than male RET altered absolute FFM, thus resulting in a greater enhancement of relative FFM. Despite equivalent or greater responses to RET or AET by female subjects, the corresponding respective increases in FFM or reductions in FM were lower than those in males, indicating that a biased dose-response relationship exists between sexes following 10 weeks of exercise training.     

Oxygen uptakes adjusted for body composition in normal-weight and obese adolescents

OBJECTIVE: To test whether resting oxygen uptake (VO(2)), submaximal VO(2), and maximal VO(2) (VO(2max)) differs between obese adolescents (n = 18; BMI > 30) and a matched normal-weight control group after adjustment for differences in fat-free mass (FFM) and fat mass (FM). RESEARCH METHODS AND PROCEDURES: FFM and FM were assessed by DXA. Resting VO(2), submaximal VO(2), and VO(2max) were measured by indirect calorimetry. RESULTS: There was no difference in resting VO(2) between groups after adjusting for FFM and FM. Submaximal VO(2) did not differ between groups after adjusting for body weight. Percentage VO(2max) and NET VO(2) (VO(2max) - resting VO(2)) were significantly higher in the obese group during submaximal exercise, however not after adjusting for body weight. VO(2max) was not significantly different between groups after adjusting for FFM. DISCUSSION: When body compositions are appropriately controlled for, resting VO(2), submaximal VO(2), and VO(2max) do not differ between obese and normal-weight adolescents. These data suggested that the higher relative VO(2) observed in obese adolescent subjects is due to their higher FM and not to an impaired VO(2max) even though they may be less physically active.     

Body composition and appetite: fat-free mass (but not fat mass or BMI) is positively associated with self-determined meal size and daily energy intake in humans

The idea of body weight regulation implies that a biological mechanism exerts control over energy expenditure and food intake. This is a central tenet of energy homeostasis. However, the source and identity of the controlling mechanism have not been identified, although it is often presumed to be some long-acting signal related to body fat, such as leptin. Using a comprehensive experimental platform, we have investigated the relationship between biological and behavioural variables in two separate studies over a 12-week intervention period in obese adults (total n 92). All variables have been measured objectively and with a similar degree of scientific control and precision, including anthropometric factors, body composition, RMR and accumulative energy consumed at individual meals across the whole day. Results showed that meal size and daily energy intake (EI) were significantly correlated with fat-free mass (FFM, P values 相似文献   

Effects of 16 mo of verified, supervised aerobic exercise on macronutrient intake in overweight men and women: the Midwest Exercise Trial

BACKGROUND: It is commonly believed that moderate aerobic exercise leads to changes in diet composition, specifically, an increase in carbohydrate intake at the expense of fat intake. OBJECTIVE: The goal was to determine the effects of a supervised, long-term program of exercise on the macronutrient intake of previously sedentary, overweight and moderately obese men and women. DESIGN: Participants (n = 74) were recruited from the university and surrounding communities and were randomly assigned to the exercise or control group. Exercise of moderate intensity was performed for 45 min/d, 5 d/wk, under supervision. Diet intake was ad libitum and was measured for energy and macronutrient composition at baseline and at 5 other occasions across the 16-mo study by use of weighing and measuring techniques. Each measurement consisted of a 2-wk period of direct measurement in the university cafeteria. Food consumption outside the cafeteria during the 2-wk periods (ie, snacks) was measured by multiple-pass 24-h dietary recall procedures. RESULTS: There were no significant differences for men or women between the exercise and control groups from baseline to 16 mo in fat, carbohydrate, or protein intake expressed as grams or as percentages of total energy intake. CONCLUSION: Sixteen months of exercise of moderate intensity does not measurably alter the macronutrient intake of young adults.     

Resting metabolic rate in obese and nonobese Chinese Singaporean boys aged 13-15 y

BACKGROUND: Previous studies investigating the hypothesis that a low resting metabolic rate (RMR) is a cause of obesity yielded discrepant findings. Two explanations for these findings are the use of imprecise methods to determine obesity and a failure to control for differences in fat mass (FM) and fat-free mass (FFM) when comparing RMR values. OBJECTIVE: This study tested the hypothesis that RMR is lower in obese than in nonobese boys (with the use of precise methods to quantify body fatness and with adjustment for differences in both FM and FFM). DESIGN: Forty Chinese Singaporean boys aged 12.8-15.1 y were recruited. Boys were classified as obese (n = 20) or nonobese (n = 20) on the basis of their adiposity index (ratio of FM to FFM: >0.60 = obese, <0.40 = nonobese) determined by dual-energy X-ray absorptiometry. RMR was determined by using indirect calorimetry. RMR values were compared by using both linear (analysis of covariance) and log-linear (analysis of covariance with log-transformed data) regression to control for differences in FM and FFM. RESULTS: Age, height, and FFM did not differ significantly between groups. Body mass was 13 kg greater and FM was 16 kg greater in the obese boys than in the nonobese boys (P < 0.001). After control for FFM and FM, RMR did not differ significantly between the groups. CONCLUSION: When body composition is appropriately controlled for, RMR does not differ significantly between obese and nonobese boys.     

Body composition predicted with a Bayesian network from simple variables

The relative contributions of fat-free mass (FFM) and fat mass (FM) to body weight are key indicators for several major public health issues. Predictive models could offer new insights into body composition analysis. A non-parametric equation derived from a probabilistic Bayesian network (BN) was established by including sex, age, body weight and height. We hypothesised that it would be possible to assess the body composition of any subject from easily accessible covariables by selecting an adjusted FFM value within a reference dual-energy X-ray absorptiometry (DXA) measurement database (1999-2004 National Health and Nutrition Examination Survey (NHANES), n 10?402). FM was directly calculated as body weight minus FFM. A French DXA database (n 1140) was used (1) to adjust the model parameters (n 380) and (2) to cross-validate the model responses (n 760). French subjects were significantly different from American NHANES subjects with respect to age, weight and FM. Despite this different population context, BN prediction was highly reliable. Correlations between BN predictions and DXA measurements were significant for FFM (R2 0·94, P?相似文献   

Body composition and fat distribution influence systemic hemodynamics in the absence of obesity: the HyperGEN Study

BACKGROUND: We have shown that increased cardiac output is related to both fat-free mass and fat mass in obesity. OBJECTIVE: We studied the association of body fat distribution and body composition with flow-resistance relations in overweight. DESIGN: We studied 521 overweight, nonobese participants in the Hypertension Genetic Epidemiology Network (HyperGEN) Study-a component of the National Heart, Lung, and Blood Institute Family Blood Pressure Program, designed to assess the genetic basis of hypertension. Participants had normal ventricular function and no cardiovascular disease: 261 with central fat distribution (CFD) (waist girth >88 cm in women and >102 cm in men) and 260 with peripheral fat distribution (PFD). Fat-free mass (FFM) and fat mass (FM) were measured by bioelectric impedance. Body composition was estimated as FM/FFM. Echocardiographic stroke volume (SV) and cardiac output (CO) were measured. RESULTS: Hypertension was present in 73% of the subjects with PFD and in 78% with CFD. Overweight with CFD was associated with greater FM/FFM in both normotensive and hypertensive participants. After FFM, age, sex, and race were controlled for, SV and CO were higher in subjects overweight with CFD than in those with PFD, whereas peripheral resistance was not significantly different. Differences in CO between CFD and PFD were reduced after further adjustment for FM. After the covariates were controlled for, hypertensive subjects had higher peripheral resistance and lower arterial compliance than did normotensive participants, but cardiac output was not significantly different. CONCLUSION: CFD is associated with more severe abnormalities in body composition and with higher CO independently of FFM in overweight, nonobese subjects.     

Acute energy compensation and macronutrient intake following exercise in active and inactive males who are normal weight

Acute energy and macronutrient intake following an Exercise and Control protocol was compared to determine if active, normal-weight males regulate acute energy intake better, demonstrating more acute accurate energy compensation capabilities, than inactive, normal-weight males after exercise. Males (21.2±1.9 years) of normal percent body fat (10.0-18.0%) and body mass index (23.4±1.7 kg/m(2)), exercising ≥150 min/week (Active: n=10) or ≤60 min/week (Inactive: n=10), completed two protocols, counterbalanced across participants. The exercise protocol (Exercise) was 45-min on a cycle ergometer and the Control protocol consisted of 45-min of reading. Sixty minutes after protocols, an ad libitum meal was provided. Energy and macronutrient intake from the meal was determined. Inactive ate significantly less energy in the ad libitum meal in Exercise as compared to Control, demonstrating acute negative energy compensation (consumed less in the meal while expending more energy in Exercise as compared to Control). Active had no difference in meal energy intake between the protocols, but due to Inactive's reduced acute energy intake in Exercise, Active demonstrated better acute energy compensation than Inactive. No difference in meal macronutrient intake was found. Overall, Active demonstrated better acute energy compensation than Inactive.     

Diet composition, energy intake, and exercise in relation to body fat in men and women

This study examined the relationships among body fat, diet composition, energy intake, and exercise in adults. Male (n = 107) and female (n = 109) adults aged 18-71 y (36.6 +/- 1.0 y, means +/- SEM) were hydrostatically weighed to determine body fat (5.7-49.0% of total weight). Diet and exercise behaviors were determined by use of a questionnaire. As body fat increased, percent of energy intake derived from fat increased (p less than 0.001) whereas the percent from carbohydrate decreased (p less than 0.001). There was no relationship between energy intake and adiposity although leanness and exercise were related (p less than 0.001). When subgroups of lean and obese subjects were compared, the lean subjects derived approximately 29% of their energy from fat and 53% from carbohydrate vs 35% and 46%, respectively, for the obese subjects. No differences were found between groups for energy intake but the lean individuals exercised more often than did the obese individuals. These data suggest that diet composition may play as important a role in fat deposition as do energy intake and lack of exercise.     

Evaluation of Lunar Prodigy dual-energy X-ray absorptiometry for assessing body composition in healthy persons and patients by comparison with the criterion 4-component model

BACKGROUND: Dual-energy X-ray absorptiometry (DXA) is widely used to assess body composition in research and clinical practice. Several studies have evaluated its accuracy in healthy persons; however, little attention has been directed to the same issue in patients. OBJECTIVE: The objective was to compare the accuracy of the Lunar Prodigy DXA for body-composition analysis with that of the reference 4-component (4C) model in healthy subjects and in patients with 1 of 3 disease states. DESIGN: A total of 215 subjects aged 5.0-21.3 y (n = 122 healthy nonobese subjects, n = 55 obese patients, n = 26 cystic fibrosis patients, and n = 12 patients with glycogen storage disease). Fat mass (FM), fat-free mass (FFM), and weight were measured by DXA and the 4C model. RESULTS: The accuracy of DXA-measured body-composition outcomes differed significantly between groups. Factors independently predicting bias in weight, FM, FFM, and percentage body fat in multivariate models included age, sex, size, and disease state. Biases in FFM were not mirrored by equivalent opposite biases in FM because of confounding biases in weight. CONCLUSIONS: The bias of DXA varies according to the sex, size, fatness, and disease state of the subjects, which indicates that DXA is unreliable for patient case-control studies and for longitudinal studies of persons who undergo significant changes in nutritional status between measurements. A single correction factor cannot adjust for inconsistent biases.     

Soft tissue composition of pigs measured with dual x-ray absorptiometry: comparison with chemical analyses and effects of carcass thicknesses.

Evidence of the validity and accuracy of dual x-ray absorptiometry (DXA) to measure in vivo body composition is limited. We compared DXA estimates made in prone and side positions with measurements of chemical composition of 20 pigs (10 barrows and 10 gilts) weighing 52-113 kg. DXA yielded similar estimates of body composition in prone and side positions. DXA estimates of body composition were significantly correlated with reference compositional values (r2 = 0.927-0.998). No significant differences were found for determinations of body weight, fat mass (FM), fat free mass (FFM), bone-free, and fat-free mass (BFFFM) between DXA and chemical determinations. DXA significantly underpredicted percent fat (% fat); it underestimated FM (20%, P > 0.05), and overestimated FFM and BFFFM (6 and 9%, respectively, P > 0.05). Differences between individual determinations of FM and % fat by chemical analyses and DXA were significantly correlated with mean values. No significant correlations were found between the differences for weight, FM, % fat, FFM and BFFFM and measurements of carcass breadth (19-28 cm) and width (15-25 cm). Total errors in determination of DXA body composition variables were similar with body thicknesses less than and greater than 24 cm. These findings indicate that DXA is a valid and accurate method for determination of soft tissue composition. Initial problems with DXA determinations of % fat apparently have been reconciled partially with revisions in soft tissue analytic software.     

Association of energy intake and macronutrient composition with overweight and obesity in malay women from klang valley

This cross-sectional study investigates the association between energy intake and macronutrient composition of the diet with overweight and obesity among Malaysian women. One hundred and fifteen adult Malay women aged 20 to 59 years (mean age 37.2±7.6 years) were interviewed. Dietary intake was assessed using the food history method. Body weight status was assessed using weight, height, waist circumference and fat percentage measurements. When energy intake was assessed for accuracy, only 41% of the subjects (n=47) were normal energy reporters. Among the normal energy reporters, 55% were of normal weight whereas 32% and 13% were overweight and obese. Mean energy intake for normal weight, overweight and obese subjects was 1685±199 kcal/day, 1810±166 kcal/day and 2119±222 kcal/day, respectively. Energy intake increased with body mass index (BMI) category. Among the overweight and obese, energy intake was respectively higher by 125 kcal/day and 434 kcal/day as compared to their normal weight counterparts (p< 0.001). There was also a significant, moderate and positive correlation between energy intake and BMI (r=0.635), waist circumference (r=0.545), and body fat percentage (r=0.534). When macronutrient composition of diet was analysed (% energy and g/1000 kcal), there was no significant difference in carbohydrate, protein or fat intake between the obese, overweight and normal weight subjects. There was also no significant correlation between macronutrient composition of the diet and body weight status. Based on these findings, we conclude that the subjects' body weight status is likely to be influenced by energy intake rather than the macronutrient composition of the diet.     

Associations between Avocado Consumption and Diet Quality,Dietary Intake,Measures of Obesity and Body Composition in Adolescents: The Teen Food and Development Study

Avocado is a nutrient-rich food that has been shown to benefit the health and diet quality of adults. In this paper, we examined if habitual intake of avocado among adolescents is associated with their diet quality, food and nutrient intake, and measures of obesity and body composition. Participants aged 12–18 years old (n = 534) from selected public and Adventist middle-high schools reported their dietary intake in a web-based food frequency questionnaire (FFQ); anthropometrics were measured during school visits. Diet quality (DQI-I) and avocado intake were calculated from the FFQ; BMI z-scores (BMIz), waist-to-height ratio (WHtR), and fat mass (FM), fat-free mass (FFM), and %body fat (%BF) were determined from the anthropometric data. Compared to non-consumers, avocado consumers had significantly higher covariate-adjusted mean scores on total DQI-I (68.3 vs. 64.6) and energy-adjusted mean scores on variety (18.8 vs. 18.0) and adequacy (36.4 vs. 33.4). Avocado consumption was significantly associated with DQI-I components adequacy (β [SE] = 0.11 [0.03]) and moderation (β [SE] = 0.06 [0.03]) but not with BMIz, WHtR, FM, FFM, and %BF. Mean intakes of fruits, vegetables, and plant protein foods, total and vegetable proteins, dietary fiber, retinol, vitamin C, calcium, magnesium, iron, and potassium were significantly higher for avocado consumers; saturated and trans fats intakes were significantly higher for non-consumers. In our adolescent population, avocado consumption was associated with higher diet quality and intake of plant-based foods and shortfall nutrients, but not with measures of obesity and body composition. Studies are needed to determine the optimal amount of avocado that would confer health benefits during adolescence.     

Diet composition and body composition in preschool children

BACKGROUND: In studies of adult humans and in animal models, dietary intakes of the macronutrients, particularly fat, are related to body composition; however, data on children are more scarce. OBJECTIVE: We sought to determine whether diet composition is related to percentage body fat in children aged 1.5-4.5 y. DESIGN: In 77 preschool children, a 4-d weighed-food record was used to determine intakes of total energy and energy from each macronutrient. An oxygen-18 dilution method was used to calculate percentage body fat. Habitual physical activity level was determined by calculating the ratio of total energy expenditure (from stable isotope analyses) to predicted basal metabolic rate. Dietary intake and body-composition data were analyzed to evaluate whether diet composition was related to body fat. Further analyses incorporating physical activity level were performed. RESULTS: Percentage body fat was not significantly correlated with dietary intake variables (total energy or percentage of energy from fat, carbohydrate, or protein) and did not differ significantly among 3 increasing levels of each dietary intake variable by analysis of variance. In multiple regression analysis, physical activity level was related to body fat whereas diet composition was not. CONCLUSIONS: We found no relations between dietary intakes of total energy, fat, carbohydrate, or protein and percentage body fat in children. The relation between fat intake and body fat may develop over time and may not be evident in preschool children. Energy expenditure, in particular physical activity level, may have a greater influence on body composition in early childhood.     

Dynamic coordination of macronutrient balance during infant growth: insights from a mathematical model

BACKGROUND: Complex dynamic changes in body composition, dietary intake, energy expenditure, and macronutrient oxidation occur during infant growth. Although previous investigators have focused on energy requirements for normal growth, little is known about the dynamic coordination of macronutrient balance. OBJECTIVE: Our objective was to develop a mathematical model of the dynamic relations between diet, macronutrient oxidation, and energy expenditure during normal infant growth. DESIGN: We developed a mathematical model that integrates longitudinal data on changes of body composition and carbon dioxide production determined with the doubly labeled water method to calculate both energy intake requirements and macronutrient oxidation rates during normal infant growth. RESULTS: The calculated fat oxidation rate was initially <20 kcal x kg(-1) x d(-1), despite the consumption of >60 kcal x kg(-1) x d(-1) of dietary fat. This discrepancy was maintained until approximately 6 mo, after which fat intake was only slightly greater than fat oxidation. Nonfat oxidation closely followed nonfat dietary intake for the duration of the period studied. Model calculations of the energy intake requirements for normal growth were slightly lower than previous estimates. The calculations were robust to variations of body weight, body composition, and diet composition input data, but depended sensitively on variations of carbon dioxide production data. CONCLUSIONS: Our model presents a dynamic picture of how macronutrient oxidation adapts in concert with dietary changes and energy expenditure to give rise to normal tissue deposition. The model integrates a variety of data in a self-consistent way, simulating the complex metabolic adaptations occurring during normal growth while extracting important physiologic information from the data that would otherwise be unavailable.     

Basal and postprandial substrate oxidation rates in obese women receiving two test meals with different protein content

BACKGROUND & AIMS: Fuel utilisation and storage in lean and obese subjects seem to be differently affected by the macronutrient distribution intake. The aim of this intervention study was to explore the extent to which the fat mass status and the macronutrient composition of an acute dietary intake influence substrate oxidation rates. METHODS: Fuel utilisation in 26 women, 14 obese (BMI = 37.1 +/- 1.1 kg/m2) and 12 lean (BMI = 20.6 +/- 0.5 kg/m2) was measured over 6 h to compare the metabolic effect of a single balanced protein (HC) meal and a high protein (HP) single meal, which were designed to supply similar energy contents (1672 kJ). The macronutrient composition as a percentage of energy of the HC meal was 55% carbohydrate, 15% protein and 30% fat, while the HP meal contained 40% carbohydrate, 30% protein and 30% fat. Nutrient oxidation rates and energy expenditure were calculated by indirect calorimetry (hood system), whereas exogenous amino acid oxidation was estimated from the 13C isotopic enrichment of breath after oral administration of L[1-13C]leucine. RESULTS: Fasting lipid oxidation was higher in the obese than in the lean women (P < 0.05), and it was significantly correlated with body fatness (P < 0.01). A single HP meal consumption produced higher postprandial fat oxidation as compared with HC meal intake (P < 0.02), in both obese and lean subjects, with no apparent changes in glucose oxidation rates. Furthermore, postprandial fat utilisation after the test meal intake was higher in obese than in the lean women (P < 0.01). The time course of 13CO2 in breath followed a similar pattern in both dietary groups, although a non-statistically significant higher trend in protein and 13C-leucine oxidation was found in the HP group. CONCLUSIONS: Net lipid oxidation depends on both short-term dietary composition intake and fat body mass, being significantly higher after a relatively high protein meal as compared to a balanced diet intake and in obese women as compared to lean controls.     

Lactation performance of exercising women

To determine whether vigorous exercise affects lactation performance, we compared well-nourished exercising (n = 8) and sedentary (n = 8) women whose infants were 9-24 wk old and exclusively breast-fed. Measurements included resting metabolic rate (RMR); maximum oxygen consumption (VO2max); plasma prolactin, cortisol, insulin, and T3; and body composition. Each subject completed a 3-d record of dietary intake, physical activity, and milk volume (by test weighing) and collected 24-h milk samples. Exercising women differed significantly from control subjects in VO2max (46.4 vs 30.3 mL.kg-1.min-1), percent body fat (21.7 vs 27.9%), total energy expenditure (3169 vs 2398 kcal/d), and energy intake (2739 vs 2051 kcal/d). There was no difference between the groups in plasma hormones or milk energy, lipid, protein, or lactose content. Exercising subjects tended to have higher milk volume (839 vs 776 g/d) and energy output in milk (538 vs 494 kcal/d). Thus, there was no apparent adverse effect of vigorous exercise on lactation performance.     

Anthropometrics and Body Composition in Adults with High-Grade Gliomas: Effects of Disease-Related Variables

Nutritional status in adults with high-grade gliomas (HGGs) has been poorly investigated. We studied anthropometrics and fat mass (FM), fat free mass (FFM), and body water in HGGs patients also in relation to disease-related variables. Fifty-one patients (17 III and 34 IV-grade) and fifty-one control group (CG) matched for sex, age, and BMI were enrolled. Neurological scales, anthropometry, bioimpedance, and blood sampling were performed and analyzed according to grade, lesion location, extent of resection, phase of treatment, current steroids and antiepileptic therapy, and age of patient. 41.2% were overweight and 15.7% obese. Compared to the CG, HGGs had similar anthropometrics and body composition. IV-grade, compared to the III, had higher BMI, waist circumference, FM and lower FFM. Only patients during concomitant radio and chemotherapy showed a negative BMI variation from baseline. In conclusion, overnutrition occurs in almost 6 out of 10 HGGs patients and is more relevant in IV-grade. Throughout all the treatment phases, there is a higher risk of weight loss occurred only during concomitant radio and chemotherapy. Body composition showed no specific features compared to controls. These results may assist intervention studies directed towards neurometabolic dietary treatment. Nutritional screening is warranted during the time course of disease.     

Dietary fat intake and insulin resistance in black and white children

OBJECTIVE: The purpose of this study was to determine whether dietary fat intake above current Acceptable Macronutrient Distribution Range (AMDR) guidelines was associated with greater insulin resistance in black and white children. RESEARCH METHODS AND PROCEDURES: We studied 142 healthy children (n = 81 whites, n = 61 blacks), 6.5 to 14 years old. Dietary composition was determined by repeated 24-hour dietary recall, body composition by DXA, visceral fat by computed tomography, and insulin sensitivity (SI) and acute insulin response to glucose (AIRg) by frequently sampled intravenous glucose tolerance test. Subjects were categorized by ethnicity (white/black) and dietary fat intake (above-AMDR/within-AMDR guidelines), and differences were analyzed by 2 x 2 analysis of covariance, adjusting for covariates. RESULTS: After adjusting for total body fat, gender, and Tanner stage, subjects consuming dietary fat above AMDR intake guidelines had lower SI and higher AIRg. This effect was specific to black children (32% lower SI and 62% higher AIRg in above-AMDR compared with within-AMDR blacks) and was not seen in whites. DISCUSSION: In black, but not white, children, those with dietary fat intake above current AMDR guidelines had lower SI and higher AIRg than those who met AMDR guidelines. These findings support current AMDR guidelines for dietary fat in black children and adolescents. The mechanism(s) underlying the ethnic differences in the relationship between dietary fat intake and SI in children require further investigation.