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1.
The effect of dietary energy supplements in children with varying degrees of chronic renal insufficiency was investigated. Despite an increased energy intake of 8-4% there was no increase growth velocity, although some patients reported improved wellbeing and activity. The proportion of dietary energy supplied by protein fell significantly during supplementation. The evidence suggests that the reduced energy intake of children with chronic renal insufficiency is a related but not causal factor in their growth retardation.  相似文献   

2.
Somatomedin activity was measured using an embryonic chick cartilage assay in 33 normal and short normal children, 23 children with pituitary growth hormone (GH) deficiency, 14 children with sexual precocity, and 13 children with chronic renal insufficiency. In normal children somatomedin activity correlated well with chronological age: low valles in early childhood rose to higher than adult levels at puberty. Children with GH deficiency had significantly lower activities and those with sexual precocity significantly higher activities than normal children. In all three groups somatomedin activity correlated well with bone age. In children with chornic renal insufficiency there was a significant correlation between decreasing somatomedin activity and both a reduced growth velocity and a falling glomerular filtration rate. Somatomedin activity and growth velocity were within normal limits in children with glomerular filtration rates above 30 ml/min/1-73 m2.  相似文献   

3.
Objective: The purpose of this study was to examine energy intake, energy expenditure, diet composition, and obesity of adolescents in Northern Greece. Research Methods and Procedures: Anthropometric measurements were taken for all participants. Height, weight, and skinfold thickness at two sites were measured. BMI and percentage body fat were calculated. Energy intake and macronutrient and micronutrient intakes were determined by a 3‐day weighed dietary diary. Energy expenditure was calculated based on calculated resting metabolic rate (RMR) 1 multiplied by an activity factor based on reported physical activity. Results: Thirty‐one percent of boys and 21% of girls had BMI corresponding to ≥25 kg/m2 at 18 years and were classified as overweight. Both overweight boys and girls reported a lower energy intake compared with their non‐overweight counterparts when expressed as kilocalories per kilogram body weight. Overweight children had a higher negative energy balance. Both overweight and non‐overweight adolescents had higher than recommended fat intakes. Mean daily carbohydrate, protein, and fat intake, expressed as grams per kilogram body weight, of overweight adolescents were significantly lower compared with the non‐overweight adolescents. Total daily carbohydrate intake, when expressed in grams, was found to be higher for non‐overweight adolescents. Both overweight boys and girls had lower iron intakes than their non‐overweight counterparts. Overweight boys had statistically lower fiber and niacin intakes than non‐overweight boys. Both overweight and non‐overweight adolescents had lower than recommended iron intakes. Furthermore, overweight adolescents consumed more snacks (potato chips, chocolate bars, pizza, cheese pie, and cream pie), more sugar, jam, and honey, and fewer legumes, vegetables, and fruits than their non‐overweight counterparts. Discussion: Reported energy intake of overweight adolescents was lower than their non‐overweight counterparts. Regarding diet composition overweight subjects had significantly lower intakes of carbohydrates compared with non‐overweight subjects. The food consumption pattern of overweight children showed less adherence to the traditional Mediterranean diet.  相似文献   

4.
Distance and velocity pattern of growth for body weight and height of 134 well-off Chandigarh boys aged 9–17 years, and 109 girls aged 9 to 16 years were studied following a mixedlongitudinal growth study design. For both body weight and height pattern-wise, Chandigarh boys showed close similarity with their American counterparts up to about 13 years of age, while girls did so till 12 years. Where after, Chandigarh children remained lighter and shorter than those of American origin and this differential may be explained on racial grounds rather than nutritional ones since all children included in this study remained free from dietary and other health related constraints. Marginally, higher height growth attainments noticed in Chandigarh children in contrast to their other Indian counterparts during initial years of adolescence shows that Chandigarh children are in process of expressing their genetic growth potential to its full which has not yet been fully achieved. The rate (velocity) of weight and height growth in Chandigarh children remained substatially lower than their sex-matched British counterparts throught the period of study. PHV in boys measured 6.4 cm/yr. and 5.4 cm/yr. in girls. It was attained at the age of 11.5 years in girls and 12.5 years in boys. Peak weight velocity in boys averaged 3.7 kg/yr., while it measured 4.6 kg/yr. in girls. In girls (11.5 yr.), PWV too was attained earlier than boys (13.5 yr.) by two years. The shorter height and lighter weight growth attainments noticed in Chandigarh children in contrast to their Western counterparts may be attributed to slower and lesser magnitude peak growth velocities recorded in Chandigarh children. The use of values presented has been recommended to monitor and assess growth attainments of Indian children residing in the Union Territory of Chandigarh.  相似文献   

5.
We developed models to predict the effect of water velocity on prey capture rates and on optimal foraging velocities of two sympatric juvenile salmonids, coho salmon and steelhead. Mean fish size was ~80 mm, the size of age I+ coho and steelhead during their second summer in Southeast Alaska streams, when size overlap suggests that competition might be strongest. We used experimentally determined prey capture probabilities to estimate the effect of water velocity on gross energy intake rates, and we modeled prey capture costs using experimental data for search and handling times and published models of swimming costs. We used the difference between gross energy intake and prey capture costs to predict velocities at which each species maximized net energy intake rate. Predicted prey capture rates for both species declined from ~75 to 30–40 prey/h with a velocity increase from 0.30 to 0.60 m·s−1. We found little difference between coho and steelhead in predicted optimum foraging velocities (0.29 m·s−1 for coho and 0.30 m·s−1 for steelhead). Although prey capture ability appears to be more important than are prey capture costs in determining optimum foraging velocities, capture costs may be important for models that predict fish growth. Because coho are assumed to pay a greater swimming cost due to a less hydrodynamic body form, we also modeled 10 and 25% increases in hydrodynamic drag to assess the effect of increased prey capture costs. This reduced optimum velocity by 0 and 0.01 m∙s−1, respectively. Habitat segregation among equal-sized coho and steelhead does not appear to be related to the effects of water velocity on their respective foraging abilities.  相似文献   

6.
Energy intake in breast fed infants is uncertain. The doubly labelled water method was used to measure, simultaneously and non-invasively, energy expenditure, energy intake, milk volume intake, energy deposition, and the energy content of breast milk in 12 "free living" breast fed babies at 5 and 11 weeks of age. The validity of this new approach was assessed in a parallel study in 12 formula fed infants. The babies who were exclusively breast fed expended 1.28 and 1.68 MJ/day at five and 11 weeks and had intakes of 1.81 and 2.22 MJ/day; these intakes were associated with normal growth but were well below those recommended previously. At five and 11 weeks the calculated energy content of breast milk was 0.24 and 0.25 MJ/100 ml, which is substantially lower than that commonly reported in milk obtained unphysiologically by expression of the breast. These data cast doubt on the widely used published standards for infant feeding.  相似文献   

7.
Natural reproduction of pallid sturgeon Scaphirhynchus albus has been limited for decades and a recruitment bottleneck is hypothesized to occur during the larval stage of development. In this study, we evaluated the effects of water velocity and temperature on the swimming activity, energy use, settling behaviour and mortality of endogenously feeding larvae. The swimming activity of drifting sturgeon larvae (i.e., fish exhibiting negative rheotaxis) increased at low water velocity. In subsequent experiments, we observed greater energy depletion and resultant mortality of larvae in no-flow environments (0 cm s−1) compared to tanks with water velocity ranging from 3.5 to 8.3 cm s−1. The growth rate of drifting larvae was positively related to water temperature (18.7–23.3°C), but reduced growth rate at low water temperature (18.7°C) resulted in protracted development that extended average drift duration by ~4 days compared to larvae reared at 23.3°C. This study provides evidence that cooler summer water temperatures, characteristic of present-day conditions in the upper Missouri River, can reduce larval development and extend both the drift duration and distance requirements of S. albus. Moreover, if dispersed into low velocity environments, such as in reservoir headwaters, larvae may experience increased mortality owing to a mismatch between early life stage drift requirements and habitat conditions in the river. Manipulation of water releases to increase seasonal water temperature below dams may aid survival of S. albus larvae by shortening the time and distance spent drifting.  相似文献   

8.

Background

Vitamin D insufficiency in children may have long-term skeletal consequences as vitamin D affects calcium absorption, bone mineralization and bone mass attainment.

Methodology/Principal Findings

This school-based study investigated vitamin D status and its association with vitamin D intake and bone health in 195 Finnish children and adolescents (age range 7–19 years). Clinical characteristics, physical activity and dietary vitamin D intake were evaluated. Blood and urine samples were collected for serum 25-hydroxyvitamin D (25-OHD) and other parameters of calcium homeostasis. Bone mineral density (BMD) and body composition were measured with dual-energy X-ray absorptiometry (DXA). Altogether 71% of the subjects were vitamin D insufficient (25-OHD <50 nmol/L). The median 25-OHD was 41 nmol/L for girls and 45 nmol/L for boys, and the respective median vitamin D intakes 9.1 µg/day and 10 µg/day. In regression analysis, after adjusting for relevant factors, 25-OHD concentration explained 5.6% of the variance in lumbar BMD; 25-OHD and exercise together explained 7.6% of the variance in total hip BMD and 17% of the variance in whole body BMD. S-25-OHD was an independent determinant of lumbar spine and whole body BMD and in magnitude surpassed the effects of physical activity.

Conclusions/Significance

Vitamin D insufficiency was common even when vitamin D intake exceeded the recommended daily intake. Vitamin D status was a key determinant of BMD. The findings suggest urgent need to increase vitamin D intake to optimize bone health in children.  相似文献   

9.

Background

Previous research has shown that oral processing characteristics like bite size and oral residence duration are related to the satiating efficiency of foods. Oral processing characteristics are influenced by food texture. Very little research has been done on the effect of food texture within solid foods on energy intake.

Objectives

The first objective was to investigate the effect of hardness of food on energy intake at lunch, and to link this effect to differences in food oral processing characteristics. The second objective was to investigate whether the reduction in energy intake at lunch will be compensated for in the subsequent dinner.

Design

Fifty subjects (11 male, BMI: 21±2 kg/m2, age: 24±2 y) participated in a cross-over study in which they consumed ad libitum from a lunch with soft foods or hard foods on two separate days. Oral processing characteristics at lunch were assessed by coding video records. Later on the same days, subjects consumed dinner ad libitum.

Results

Hard foods led to a ∼13% lower energy intake at lunch compared to soft foods (P<0.001). Hard foods were consumed with smaller bites, longer oral duration per gram food, and more chewing per gram food compared to the soft foods (P<0.05). Energy intake at dinner did not differ after both lunches (P = 0.16).

Conclusions

Hard foods led to reduced energy intake compared to soft foods, and this reduction in energy intake was sustained over the next meal. We argue that the differences in oral processing characteristics produced by the hardness of the foods explain the effect on intake. The sustained reduction in energy intake suggests that changes in food texture can be a helpful tool in reducing the overall daily energy intake.  相似文献   

10.
Background: Increased intake of sugar‐sweetened beverages and fruit juice has been associated with overweight in children. Objective: This study prospectively assessed beverage consumption patterns and their relationship with weight status in a cohort of children born at different risk for obesity. Methods and Procedures: Participants were children born at low risk (n = 27) or high risk (n = 22) for obesity based on maternal prepregnancy BMI (kg/m2). Daily beverage consumption was generated from 3‐day food records from children aged 3–6 years and coded into seven beverage categories (milk, fruit juice, fruit drinks, caloric and noncaloric soda, soft drinks including and excluding fruit juice). Child anthropometric measures were assessed yearly. Results: High‐risk children consumed a greater percentage of daily calories from beverages at age 3, more fruit juice at ages 3 and 4, more soft drinks (including fruit juice) at ages 3–5, and more soda at age 6 compared to low‐risk children. Longitudinal analyses showed that a greater 3‐year increase in soda intake was associated with an increased change in waist circumference, whereas a greater increase in milk intake was associated with a reduced change in waist circumference. There was no significant association between change in intake from any of the beverage categories and change in BMI z‐score across analyses. Discussion: Children's familial predisposition to obesity may differentially affect their beverage consumption patterns. Future research should examine the extent to which dietary factors may play a role in pediatric body fat deposition over time.  相似文献   

11.
《Endocrine practice》2014,20(6):589-596
ObjectiveVarious physiological changes occur in maternal thyroid economy during pregnancy. This review focuses on the events taking place during gestation that together strongly influence maternal thyroid function.MethodsScientific reports on maternal thyroid physiology in pregnancy.ResultsDuring the 1st trimester, human chorionic gonadotropin (hCG) induces a transient increase in free thyroxine (FT4) levels, which is mirrored by a lowering of thyroid-stimulating hormone (TSH) concentrations. Following this period, serum FT4 concentrations decrease of approximately 10 to 15%, and serum TSH values steadily return to normal. Also starting in early gestation, there is a marked increase in serum thyroxine-binding globulin (TBG) concentrations, which peak around midgestation and are maintained thereafter. This event, in turn, is responsible for a significant rise in total T4 and triiodothyronine (T3). Finally, significant modifications in the peripheral metabolism of maternal thyroid hormones occur, due to the expression and activity of placental types 2 and 3 iodothyronine deiodinases (D2 and D3, respectively).ConclusionIn line with these variations, both free thyroid hormone and TSH reference intervals change throughout pregnancy, and most scientific societies now recommend that method-and gestation-specific reference ranges be used for interpreting results in pregnancy.The maternal iodide pool reduces during pregnancy because of increased renal clearance of iodine and transfer of iodine to the feto-placental unit. This results in an additional requirement of iodine during pregnancy of ~ 100% as compared to nonpregnant adults. In accordance, the recommended iodine intake in pregnancy is 250 μg/day. A daily iodine intake below this threshold poses risks of various degrees of thyroid insufficiency for both the mother and the fetus. (Endocr Pract. 2014;20:589-596)  相似文献   

12.
Abstract Reproduction has been shown to be costly in viviparous skinks, both in terms of survival and in terms of growth and future reproductive output. One possible source of such costs could be a reduction in food intake, with an associated reduction in energy available for maintenance and future reproduction. Therefore, I compared food intake in male and female southern water skinks (Eulamprus tympanum), to determine whether food intake was reduced during reproduction in either sex. In addition, I measured the relationship between reduction in food intake and the total volume of offspring or testis. A reduction in food intake proportional to the volume of offspring suggests that costs associated with reduced energy intake may be fecundity dependent. Food intake was estimated using the total volume of stomach contents of individuals. Females ate significantly less (mean volume of stomach contents = 0.13mL) than males (mean = 0.36mL) just before parturition in January, when embryos were largest. After parturition, females ate significantly more than males. Otherwise, there were no significant differences between the food intake of males and females. Females reduced food intake by eating smaller food items. Females with relatively large numbers of ova or embryos ate relatively less, and therefore decreased food intake in females may be a fecundity-dependent cost of reproduction in these lizards. Males did not reduce food intake during periods when testes were enlarged and mating occurred. Decreased food intake during reproduction is probably an important source of reproductive costs to females of these viviparous lizards, but does not appear to be important in males.  相似文献   

13.
OBJECTIVE--To determine whether the inhaled glucocorticosteroid budesonide has any adverse effect on short term linear growth in children with mild asthma. SETTING--Outpatient clinic in secondary referral centre. PATIENTS--15 children aged 6-13 years with normal statural growth velocity during the previous year, no signs of puberty, and no use of systemic or topical steroids in the two months before the study. DESIGN OF INTERVENTIONS--Double blind, randomised crossover trial with two active periods in which budesonide was given in divided daily doses of 200 micrograms and 800 micrograms. During run in and two washout periods placebo was given. After the second washout period the children received open treatment with 400 micrograms budesonide daily. All periods were of 18 days'' duration. MAIN OUTCOME MEASURE--Growth of the lower leg as measured twice a week by knemometry. RESULTS--Mean growth velocity of the lower leg was 0.63 mm/week during run in and during washout 0.64 mm/week. Budesonide treatment was associated with a significant dose related reduction of growth velocity: the mean reduction in growth velocity during treatment was 0.11 (95% confidence interval -0.15 0.36 (0.13 to 0.59) mm/week with 800 micrograms budesonide (p less than 0.05; Page''s test). During treatment with 400 micrograms budesonide a reduction of 0.17 (-0.10 to 0.45) mm/week was found. CONCLUSIONS--Treatment with inhaled budesonide is associated with a dose related suppression of short term linear growth in children with mild asthma.  相似文献   

14.
Growth failure (GF) is one of the major complications affecting children with inflammatory bowel disease. The faltering is temporary in 40-50% of cases and prolonged in 10-20% in Crohn's disease (CD). Such failure is rare in children with ulcerative colitis (5%). This complication is often associated with retarded bone development and delayed onset of sexual maturation. The delayed linear growth has a variety of causes including insufficient intake due to anorexia and the inflammatory process with increased energy and protein expenditure. Other factors are increased intestinal loss, secondary hypopituitarism and treatment with steroids. Therapeutic strategies of CD in children have changed this last decade by introducing new therapeutic agents such as topic steroids, immunosuppressors, anti-TNF (antibody and notably in children enteral nutrition which has shown its efficacy in inducing remissions of active CD, restoring nutritional status and stimulation of linear growth. The results of a recent prospective multicentric study over 2 years in 82 CD show that severe GF (-2 SD) is initially present in 15% (n = 12), among them 11 remain < -2SD after 2 years of follow-up. Six patients who were on the normal range initially increased their GF during the follow-up (< -2SD) (total 21% < -2SD (n = 17) at 2 years). At inclusion in this group there was no difference in growth velocity, used of steroids, enteral nutrition or severity of CD as compared to the group with no GF. It suggests that new treatment strategy should be developed in the future for this specific complication of paediatric CD.  相似文献   

15.
Individuals with a later preference for the daily activities (evening types) tend to have unhealthier behaviors, which could increase their risk for obesity when compared those with an earlier preference (morning types). Furthermore, later food intake timing, another behavior more characteristic of evening types, has been associated with obesity. However, chronotype differences in the long-term weight change and the role of chronotype in the association between energy intake timing and obesity risk are not clear. To study this we first examined the independent associations of chronotype and energy intake timing with anthropometric changes and then whether chronotype modified the association between energy intake timing and obesity risk. Our data included 1097 Finns from DILGOM (DIetary Lifestyle and Genetic Determinants of Obesity and Metabolic syndrome) 2007 (baseline) and 2014 (follow-up) and from Findiet 2007. Chronotype was assessed with a shortened version of Horne and Östberg’s morningness–eveningness questionnaire. Energy intake timing (as percentages of the total energy intake in the morning/evening) was assessed with 48-h dietary recalls. Weight, body mass index (BMI), and waist circumference were based on measured and self-reported values. Analysis of co-variance and multivariable logistic regression models were used for statistical analyses. Evening typed women had greater weight gain (+ 2.3 kg vs. + 0.3 kg, = 0.016) and increase in BMI (0.7 kg/m2 vs. ?0.1 kg/m2, = 0.024) than morning typed women. After excluding participants with depression, these associations attenuated to non-significant. Compared to participants whose energy intake was proportionally lowest during evening, those with proportionally highest energy intake during evening were more likely with obesity (BMI≥ 30 kg/m2) after follow-up (OR 1.97, 95% CI 1.21–3.21, Ptrend = 0.042). Participants’ chronotype did not modify this association (Pinteract = 0.95). In conclusion, our findings indicated that evening energy intake may play a role in obesity regardless of the chronotype. Furthermore, evening typed women were more prone to increases in their anthropometrics, which seem to be at least partly explained by depression. Further studies of this topic are warranted.  相似文献   

16.
With farmed British Columbia (BC) oysters containing higher cadmium concentrations than wild oysters, long-term exposure to cadmium through consumption of oysters has the potential to cause health risks. This study reports on a risk assessment for cadmium intake resulting from the consumption of BC-cultured oyster. The study concludes that Health Canada's current recommended BC-cultured oyster consumption rate for Canadians of 12 oysters per month exceeds the Agency for Toxic Substances and Disease Registry chronic oral minimal risk levels (MRL) of 0.2 μ g·kg? 1·day? 1 by approximately 4-to 5-fold and reaches the Food and Agriculture Organization/World Health Organization (FAP/WHO) reference dose of 1 μg·kg?1·day?1 for cadmium consumption for Canadians. This suggests that although the current recommended maximum oyster consumption rates is consistent with the FAO/WHO and U.S. Environmental Protection Agency limits for acceptable risk, it leaves little or no room for error or uncertainty. This is noteworthy as recent studies demonstrate toxicological effects at cadmium intakes of 0.43 to 0.71 μ gCd·kg?1·day?1. This study indicates that a lower maximum BC-cultured oyster rate should be considered, particularly for high risk groups, including women with low iron stores, people with renal impairment, smokers, children, and indigenous people who consume organ meats of games and wildlife other than shellfish.  相似文献   

17.
Midlife women tend to gain weight with age, thus increasing risk of chronic disease. The purpose of this study was to examine associations between overweight/obesity and behavioral factors, including eating frequency, in a cross‐sectional national sample of midlife women (n = 1,099) (mean age = 49.7 years, and BMI = 27.7 kg/m2). Eating behaviors and food and nutrient intakes were based on a mailed 1‐day food record. BMI was calculated from self‐reported height and weight, and level of physical activity was assessed by self‐reported questionnaire. After exclusion of low‐energy reporters (32% of sample), eating frequency was not associated with overweight/obesity (P > 0.05) and was not different between BMI groups (normal, 5.21 ± 1.79; overweight, 5.16 ± 1.74; obese, 5.12 ± 1.68, P = 0.769). Adjusted logistic regression showed that eating frequency, snacking frequency, breakfast consumption, eating after 10 pm and consuming meals with children or other adults were not significantly associated with overweight/obesity. Total energy intake increased as eating frequency increased in all BMI groups, however, obese women had greater energy intake compared to normal weight women who consumed the same number of meals and snacks. Intake of fruit and vegetables, whole grains, dietary fiber, dairy, and added sugars also increased as eating frequency increased. While eating frequency was not associated with overweight/obesity, it was associated with energy intake. Thus, addressing total energy intake rather than eating frequency may be more appropriate to prevent weight gain among midlife women.  相似文献   

18.
N-terminal pro-brain natriuretic peptide (NT-proBNP) is a routinely used prognostic parameter in patients with pre-capillary pulmonary hypertension (PH). As it accumulates in the presence of impaired renal function, the clinical utility of NT-proBNP in PH patients with concomitant renal insufficiency remains unclear. In a retrospective approach, patients with pre-capillary PH (group I or IV) and concomitant renal insufficiency at time of right heart catheterization (glomerular filtration rate (GFR) ≤60 ml/min/1.73 m2) were identified out of all prevalent pre-capillary PH patients treated at a single center. Forty patients with renal insufficiency (25.8%) were identified and matched regarding hemodynamic parameters with a control group of 56 PH patients with normal renal function (GFR >60 ml/min/1.73 m2). Correlations of NT-proBNP levels with hemodynamic and prognostic parameters (time to clinical worsening and overall survival) were assessed. Overall, GFR correlated inversely with NT-proBNP and had the strongest influence on NT-proBNP levels in a stepwise multiple linear regression model including hemodynamic parameters and age (r2 = 0.167). PH patients with renal insufficiency had significant higher levels of NT-proBNP (median: 1935 ng/l vs. 573 ng/l, p = 0.001). Nevertheless, NT-proBNP correlated with invasive hemodynamic parameters in these patients. Using higher cut-off values than in patients with preserved renal function, NT-proBNP levels were significantly associated with time to clinical worsening (>1660 ng/l, p = 0.001) and survival (>2212 ng/l, p = 0.047) in patients with renal insufficiency. Multivariate Cox’s proportional hazards analysis including established prognostic parameters, age and GFR confirmed NT-proBNP as an independent risk factor for clinical worsening in PH patients with renal insufficiency (hazard ratio 4.8, p = 0.007). Thus, in a retrospective analysis we showed that NT-proBNP levels correlated with hemodynamic parameters and outcome regardless of renal function. By using higher cut-off values, NT-proBNP seems to represent a valid clinical marker even in PH patients with renal insufficiency.  相似文献   

19.
Trade-offs in Energy Allocation During Lactation   总被引:1,自引:0,他引:1  
SYNOPSIS. During lactation, mothers require energy to meet bothmaternal and offspring requirements. If a mother exports toomuch energy to dependent offspring (in milk), her weight lossmay be excessive and maternal risk may increase. Conversely,too little energy allocation to offspring may reduce the growthrate or induce mortality of dependent offspring. This paradigmwas evaluated in cotton rats (Sigmodon hispidus) supportingsmall (3 pup) and large (6 pup) litters from early to late lactation.Several types of evidence indicate that physiological constraintslimit the ability of mothers with large litters to provide resourcesto offspring. Mothers with large litters produced a dilute,energy-poor milk and their rates of food intake, weight lossand energy export per litter appeared to approach physiologicalmaxima. Whereas the energy exported to pups in small littersincreased from early to late lactation, the energy flow perpup in large litters was consistently low; consequently, offspringin large litters had low growth rates. An increase in eithermaternal food intake or weight loss (catabolism of maternaltissue) could have provided additional energy to offset thelow growth rate of pups in large litters. However, mothers withlarge litters did not substantially increase their food intakeor weight loss compared with mothers supporting small litters.These results indicate that the maternal support of offspringin large litters is limited. The pattern of energy allocationshown by cotton rats with large litters likely reflects a compromisebetween meeting maternal and offspring energy requirements (cf.,Parker and Macnair, 1979). The energy flow is greater than optimalfor the parent but less than optimal for the offspring. Lessmaternal-offspring conflict occurs in small than large littersbecause offspring in small litters maintain a high growth rateat a relatively low maternal cost. Yet, under favorable environmentalconditions, the reduction in maternal-offspring conflict hasno apparent fitness benefit.  相似文献   

20.
Objective: Eating in the absence of hunger (EAH) may be a genetically influenced phenotype of overweight children, but evidence is limited. This research evaluated the heritability (h2) of EAH and its association with overweight among Hispanic children 5 to 18 years old. Genetic and environmental associations of EAH with overweight, fat mass, and key hormonal regulators of food intake were also evaluated. Research Methods and Procedures: A family design was used to study 801 children from 300 Hispanic families. Weighed food intakes were used to measure EAH after an ad libitum dinner providing 50% of estimated energy needs. Fasting ghrelin, amylin, insulin, and leptin were measured by immunoassays. Measured heights, weights, and fat mass (using DXA) were obtained. Total energy expenditure (TEE) was measured by room respiration calorimetry. Results: On average, children consumed 41% of TEE at the dinner meal, followed by an additional 19% of TEE in the absence of hunger. Overweight children consumed 6.5% more energy at dinner (p < 0.001) and 14% more energy in the absence of hunger (p < 0.001) than non‐overweight children. Significant heritabilities were seen for EAH (h2 = 0.51) and dinner intake (h2 = 0.52) and for fasting levels of ghrelin (h2 = 0.67), amylin (h2 = 0.37), insulin (h2 = 0.37), and leptin (h2 = 0.34). Genetic correlations were seen between eating behavior and fasting hormones, suggesting common underlying genes affecting their expression. Discussion: This research provides new evidence that overweight Hispanic children exhibit elevated levels of hyperphagic eating behaviors that are influenced by genetic endowment.  相似文献   

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