The impact of disease-related immobilization on thigh muscle mass and strength in older hospitalized patients.

BACKGROUND: We assessed the quantitative changes in muscle mass and strength during 2 weeks of hospitalization in immobile and mobile acutely ill hospitalized older adults. METHODS: Forty-one patients (82.4 ± 6.6 years, 73.0% females) participated in this prospective longitudinal observational study. Mobility status was defined according to walking ability as described in the Barthel-Index. Functional status, including handgrip strength and isometric knee-extension strength, and mid-thigh magnetic resonance imaging (MRI) measurements of cross-sectional area (CSA) were conducted on admission and at discharge. RESULTS: Twenty-two participants (54%) were immobile and 19 (46%) mobile. In all, 54.0 and 12.0% were at risk of malnutrition and malnourished, respectively. The median time between baseline and follow-up for MRI scans were 13 days in mobile and immobile participants (P = 0.072). Mid-thigh muscle and subcutaneous fat CSA significantly decreased by 3.9cm2 (5.0%, P = 0.002) and 5.3cm2 (5.7%, P = 0.036) during hospitalization whereas intermuscular fat remained unchanged in immobile subjects. No significant changes were observed in mobile patients. In a regression analysis, mobility was the major independent risk factor for changes in mid-thigh muscle CSA as a percentage of initial muscle area (P = 0.022) whereas other variables such as age (P = 0.584), BMI (P = 0.879), nutritional status (P = 0.835) and inflammation (P = 0.291) were not associated with muscle mass changes. There was a significant decrease in isometric knee extension strength (P = 0.002) and no change in handgrip strength (P = 0.167) in immobile patients whereas both parameters increased significantly over time in mobile patients (P = 0.048 and P = 0.012, respectively). CONCLUSIONS: Two weeks of disease-related immobilization result in a significant loss of thigh muscle mass and muscle strength in older patients with impaired mobility. Concomitantly, there was a significant reduction of subcutaneous adipose tissue in immobile older hospitalized patients whereas no changes were observed in intermuscular fat among these patients. These data highlight the importance of mobility support in maintaining muscle mass and function in older hospitalized patients.

Effect of Over- and Underfeeding on Body Composition and Related Metabolic Functions in Humans.

PURPOSE OF REVIEW: Methodological limitations of body composition methods limit the validity of changes in body composition that are used to interpret metabolic outcome parameters of weight loss and weight gain. RECENT FINDINGS: Direct assessment of energy balance is necessary for the assessment of early weight changes (i.e., within the 1st week of weight change), whereas body composition analysis with a high accuracy and a low minimal detectable change is recommended to assess ongoing changes. The sequence of underfeeding and overfeeding impacts the method inherent assumptions, and the considerable day-to-day and inter-individual variance in body composition changes is a challenge to the precision of methods. Weight loss-associated changes in body composition do not resemble their changes with subsequent hypercaloric re-feeding. Individual body components are related to specific metabolic functions where the structure-function relationships change with changes in energy balance. Analysis of structure-function relationships in response to weight changes needs to address (a) the validity, precision, and different outcome parameters of body composition methods and (b) the variance of results taking into account study protocols and the dynamics of weight changes. As for future studies, repeated measurements of body weight, body composition, and metabolic functions are needed before, during, and after weight changes focusing on the intra- and interindividual variances of weight change rather than on mean data only.

Relationship between submaximal oxygen uptake, detailed body composition, and resting energy expenditure in overweight subjects.

OBJECTIVE: We investigated the impact of detailed body composition on aerobic fitness to determine whether regional components of fat mass have independent effects on VO2submax , and whether VO2submax and detailed body composition independently explain variation in REE. METHODS: 71 healthy adults (80% female, 20% male, BMI 28.2-43.8 kg/m(2) ) were investigated. Body composition was measured by the four-compartment model together with whole body magnetic resonance imaging (MRI) to assess high and low metabolic rate organs and regional fat depots. VO2submax was estimated at 75% of predicted maximum heart rate. RESULTS: There was a strong association between VO2submax and FFM and all organ masses except for heart. Skeletal muscle mass accounted for 34.8% of the variance in VO2submax . In addition, subcutaneous adipose tissue (SAT) of extremities explained additional 14.4%. FFM and FM explained 71.3% of the variance in REE. Including the components of FFM and FM, the explained variance in REE increased by about 5.8%; skeletal muscle mass explained 70.0% of the variance in REE and kidney and liver masses explained additional 7.1%. VO2submax correlated with REE. Taking into account body composition, VO2submax did not add to the variance in REE. CONCLUSION: FFM is a determinant of both VO2submax and REE. Modeling either REE or VO2submax from individual components of FFM, about 77.1% of variance in REE (by muscle, liver and kidneys mass) and 34.8% of variance in VO2submax (by skeletal muscle mass) could be explained. FM explained additional variance in REE, whereas SAT of extremities added to the variance in VO2submax only.

Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from green tea in humans.

PURPOSE: To investigate the influence of dietary proteins (casein, soy protein) and skimmed milk on the plasma kinetics of green tea (GT) catechins. METHODS: In a randomized cross-over design with one-week intervals, 24 healthy normal-weight women consumed a test drink containing 1.75 g GT extract with or without the addition of different proteins. Treatments were GT (control), GT with skimmed milk (GT + M), GT with caseinate (GT + CS), or GT with soy protein (GT + S). Venous blood samples were taken before and several times during a period of 4.5 h after consumption of the test drink. Plasma concentrations of catechins were analyzed by HPLC with electrochemical detection. RESULTS: Compared to control, consumption of GT with milk, caseinate, or soy protein significantly reduced the bioavailability (mean area under the plasma concentration-time curve) of total catechins (means ± SEM; GT + M, 87 ± 5%; GT + CS, 79 ± 5%; GT + S, 88 ± 4%), epigallocatechin gallate (GT + M, 68 ± 4%; GT + CS, 63 ± 5%; GT + S, 76 ± 5%), and epicatechin gallate (GT + M, 68 ± 5%; GT + CS, 66 ± 6%; GT + S, 77 ± 6%), while the bioavailability of non-galloylated catechins such as epigallocatechin (GT + M, 134 ± 9%; GT + CS, 118 ± 9 %; GT + S, 123 ± 8%) and epicatechin (GT + M, 125 ± 10%; GT + CS, 114 ± 11%; GT + S, 110 ± 8%) significantly increased. No significant differences in bioavailability of GT catechins were observed between the treatments GT + M, GT + CS, or GT + S. CONCLUSION: Simultaneous ingestion of dietary proteins reduces the bioavailability of galloylated catechins from GT in humans.

Energy allocation between brain and body during ontogenetic development.

OBJECTIVE: We here studied how energy is allocated between brain and body both during the ontogenetic development from a child to an adult and during weight loss. METHODS: We investigated 180 normal weight female and male children and adolescents (aged 6.1-19.9 years) as well as 35 overweight adolescents undergoing weight reduction intervention. 52 normal weight and 42 obese adult women were used for comparison. We assessed brain mass by magnetic-resonance-imaging and body metabolism by indirect calorimetry. To study how energy is allocated between brain and body, we measured plasma insulin, since insulin fulfils the functions of a glucose allocating hormone, i.e., peripheral glucose uptake depends on insulin, central uptake does not. We used reference data obtained in the field of comparative biology. In a brain-body-plot, we calculated the distance between each subject and a reference mammal of comparable size and named the distance "encephalic measure." With higher encephalic measures, more energy is allocated to the brain. RESULTS: We found that ontogenetic development from a child to an adult was indicated by decreasing encephalic measures in females (r = -0.729, P < 0.001) and increasing plasma insulin concentrations (F = 6.6, P = 0.002 in females and F = 8.6, P < 0.001 in males). Weight loss of about 5 kg in females and about 9 kg in males resulted in reduced insulin concentrations and increased encephalic measures. CONCLUSION: Our results indicate that the share of energy allocated to the brain increased with weight loss, but decreased during the ontogenetic development from childhood to adolescence. These developmental changes in brain-to-body energy allocation appear to be driven by increasing plasma insulin concentrations.

APOE ε4 is associated with higher vitamin D levels in targeted replacement mice and humans.

The allele ε4 of apolipoprotein E (APOE), which is a key regulator of lipid metabolism, represents a risk factor for cardiovascular diseases and Alzheimer's disease. Despite its adverse effects, the allele is common and shows a nonrandom global distribution that is thought to be the result of evolutionary adaptation. One hypothesis proposes that the APOE ε4 allele protects against vitamin D deficiency. Here we present, for the first time, experimental and epidemiological evidence that the APOE ε4 allele is indeed associated with higher serum vitamin D [25(OH)D] levels. In APOE4 targeted replacement mice, significantly higher 25(OH)D levels were found compared with those in APOE2 and APOE3 mice (70.9 vs. 41.8 and 27.8 nM, P<0.05). Furthermore, multivariate adjusted models show a positive association of the APOE ε4 allele with 25(OH)D levels in a small collective of human subjects (n=93; P=0.072) and a general population sample (n=699; P=0.003). The novel link suggests ε4 as a modulator of vitamin D status. Although this result agrees well with evolutionary aspects, it appears contradictory with regard to chronic diseases, especially cardiovascular disease. Large prospective cohort studies are now needed to investigate the potential implications of this finding for chronic disease risks.

Enriched cereal bars are more effective in increasing plasma quercetin compared with quercetin from powder-filled hard capsules.

The flavonol quercetin, is one of the major flavonoids found in edible plants. The bioavailability of quercetin in humans may be influenced by the food matrix in which it is consumed as well as by its chemical and physical form. The objective of the present study was to investigate the biokinetics of quercetin from quercetin-enriched cereal bars and quercetin powder-filled hard capsules. In a randomised, single-blinded, diet-controlled cross-over study, six healthy women aged 22-28 years took a single oral dose of approximately 130 mg quercetin equivalents from either quercetin-enriched cereal bars (containing 93·3 % quercetin aglycone plus 6·7 % quercetin-4'-glucoside) or quercetin powder-filled hard capsules (100 % quercetin aglycone). Blood samples were drawn before and after quercetin administration over a 24 h period. The concentrations of quercetin and its monomethylated derivatives, isorhamnetin (3'-O-methyl quercetin) and tamarixetin (4'-O-methyl quercetin), were measured by HPLC with fluorescence detection after plasma enzymatic treatment. The systemic availability as determined by comparing the plasma concentration-time curves of quercetin was found to be five times and the cmax values six times higher after ingestion of 130 mg quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In contrast, tmax did not differ significantly between the two treatments. The cmax values for isorhamnetin and tamarixetin were four and nine times higher after ingestion of quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In conclusion, quercetin from quercetin-enriched cereal bars is significantly more bioavailable than from quercetin powder-filled hard capsules.

Relationship between Birth Weight, Early Growth Rate, and Body Composition in 5- to 7-Year-Old Children.

BACKGROUND: Programing of body composition during intrauterine growth may contribute to the higher risk for cardio-metabolic disease in individuals born small or large for gestational age (SGA, LGA). Compensations of intrauterine growth by catch-up or catch-down postnatal growth may lead to adverse consequences like a thin-fat phenotype. METHODS: The impact of (i) birth weight as well as (ii) the interaction between birth weight and catch-up or catch-down growth during the first 2 years of life on fat-free mass index (FFMI) and fat mass index (FMI) in 3,204 5-7-year-old children were investigated using Hattori's body composition chart. Body composition results were compared to appropriate for gestational age (AGA) birth weight with the same body mass index (BMI). RESULTS: In total, 299 children at age 5-7 years were categorized as SGA, 2,583 as AGA, and 322 as LGA. When compared to AGA-children, BMI at 5-7 years of age was higher in LGA-children (15.5 vs. 16.2 kg/m2; p < 0.001) but not different in SGA-children. Compared to AGA with the same BMI, LGA was associated with higher FMI and a lower FFMI in 5-7-year-old girls. This phenotype was also seen for both sexes with catch-down growth during the first 2 years of life whereas catch-up growth prevented the higher FMI and lower FFMI per BMI. By contrast, SGA was associated with a higher FFMI and lower FMI in 5-7-year-old boys compared to AGA boys with the same BMI. This phenotype was also seen with catch-down growth in both genders whereas catch-up growth in girls led to more gain in FMI per BMI. CONCLUSION: LGA with a compensatory catch-down postnatal growth may be a risk factor for the development of disproportionate gain in fat over lean mass whereas SGA with a catch-down postnatal growth seems to favor the subsequent accretion of lean over fat mass. A higher propensity of lean mass accretion during postnatal growth in boys compared to girls explains sex differences in these phenotypes.

No evidence for a thermic effect of the dietary flavonol quercetin: a pilot study in healthy normal-weight women.

Our objective was to investigate the effect of quercetin supplementation on fasting resting energy expenditure (REE) and respiratory quotient (RQ) in humans. Six healthy, normal-weight women (mean age 25.5 ± 1.6 years, body mass index 21.4 ± 1.5 kg/m(2)) participated in a randomized, placebo-controlled, double-blinded crossover study. Treatments were administered as capsules of 150 mg quercetin (aglycone) or placebo. The acute response was measured by indirect calorimetry for 3 h following ingestion. Blood pressure and pulse rate were assessed in 30-min intervals. On the following day, 24 h after capsule intake, a follow-up measurement was performed. Baseline (t (0)) REE adjusted for fat-free mass was 4.7 ± 0.26 kJ/min (quercetin) and 4.8 ± 0.35 kJ/min (placebo) and did not significantly change between baseline and end (t (180)) in either group (P = 0.992 for time effect in repeated measures analysis of variance; P = 0.581 for time × treatment interaction). Mean RQ was 0.78 ± 0.04 (quercetin) and 0.77 ± 0.04 (placebo). RQ values decreased slowly and to a similar extent during both treatments (P < 0.001 for time; quercetin, -0.09 ± 0.05; placebo, -0.08 ± 0.03; P = 0.877 for time × treatment interaction). Resting systolic and diastolic blood pressure, pulse pressure as well as resting pulse rate did not significantly change between baseline and end in either treatment group. No significant differences were found between the results of the baseline measurement and 24 h after treatment. In conclusion, the present pilot study provides no evidence for a thermic effect of quercetin in humans.

Body Composition Characteristics of a Load-Capacity Model: Age-Dependent and Sex-Specific Percentiles in 5- to 17-Year-Old Children.

INTRODUCTION: Body composition assessment is superior to the use of body mass index (BMI) to characterize the nutritional status in pediatric populations. For data interpretation, suitable reference data are needed; hence, we aimed to generate age-dependent and sex-specific body composition reference data in a larger population of children and adolescents in Germany. METHODS: This is a cross-sectional study on a representative group of 15,392 5- to 17-year-old children and adolescents. Body composition was assessed by bioelectrical impedance analysis using a population-specific algorithm validated against air displacement plethysmography. Age- and sex-specific percentiles for BMI, fat mass index (FMI), fat-free mass index (FFMI), and a "load-capacity model" (characterized by the ratios of fat mass [FM]/ fatt-free mass [FFM] and FM/FFM2) were modeled using the LMS method. RESULTS: BMI, FMI, FFMI, FM/FFM, and FM/FFM2 curves showed similar shapes between boys and girls with steady increases in BMI, FMI, and FFMI, while FM/FFM2-centiles decreased during early childhood and adolescence. Sex differences were observed in FMI and FM/FFM percentiles with increases in FMI up to age 9 years followed by a steady decrease in FM/FFM during and after puberty with a fast-growing FFMI up to age 17 in boys. The prevalence of low FFM relative to FM reached more than 60% in overweight children and adolescents. CONCLUSION: These pediatric body composition reference data enable physicians and public health scientists to monitor body composition during growth and development and to interpret individual data. The data point out to an early risk of sarcopenia in overweight children and adolescents.

Clustering of lifestyle factors and association with overweight in adolescents of the Kiel Obesity Prevention Study.

OBJECTIVE: To identify lifestyle clusters in adolescents and to characterize their association with overweight and obesity. DESIGN: Cross-sectional and longitudinal data of the Kiel Obesity Prevention Study. SETTING: Schools in Kiel, Germany. SUBJECTS AND METHODS: Cross-sectional data of 1894 adolescents aged 14 years and 4-year longitudinal data of a subsample of 389 children aged 10 and 14 years. Self-reported data of physical activity, modes of commuting to school, media time, nutrition, alcohol consumption and smoking were used to identify lifestyle clusters with two-step cluster analysis. Obesity indices (height, weight, waist circumference and fat mass (FM)) were measured. RESULTS: Three lifestyle clusters were identified: a 'low activity and low-risk behaviour' cluster (cluster 1: n 740, 39·1 %); a 'high media time and high-risk behaviour' cluster (cluster 2: n 498, 26·3 %); and a 'high activity and medium-risk behaviour' cluster (cluster 3: n 656, 34·6 %). Strictly speaking, none of these clusters was considered to be markedly healthy. The prevalence of overweight and obesity tended to be lower in cluster 3 (15·9 %) than in clusters 1 (20·4 %) and 2 (20·5 %; P = 0·053). Longitudinally, 4-year changes in FM were found to be lowest in cluster 2, but the 4-year incidence rate of obesity was lowest in cluster 3. CONCLUSIONS: Explicit healthy lifestyles do not exist, but an active lifestyle reduces the incidence of obesity. In adolescents, health promotion should take into account the diversity of lifestyles and address specific lifestyle clusters.

Determinants of the prevalence and incidence of overweight in children and adolescents.

OBJECTIVE: To systematically analyse determinants of overweight prevalence and incidence in children and adolescents, as a basis of treatment and prevention. DESIGN: Cross-sectional and longitudinal data of the Kiel Obesity Prevention Study (KOPS). SETTING: Schools in Kiel, Germany. SUBJECTS: Cross-sectional data from 6249 students aged 5-16 years and 4-year longitudinal data from 1087 children aged 5-11 years. Weight status of students was assessed and familial factors (weight status of parents and siblings, smoking habits), social factors (socio-economic status, nationality, single parenting), birth weight as well as lifestyle variables (physical activity, media time, nutrition) were considered as independent variables in multivariate logistic regression analyses to predict the likelihood of the student being overweight. RESULTS: The cross-sectional data revealed the prevalence of overweight as 18·3 % in boys and 19·2 % in girls. In both sexes determinants of overweight prevalence were overweight and obese parents, overweight siblings, parental smoking, single parenthood and non-German nationality. High birth weight and low physical activity additionally increased the risk in boys. High media time and low parental education were significant determinants in girls. Effect of media time was mediated by maternal weight status in boys as well as by socio-economic status and age in girls. From the longitudinal data, the 4-year cumulative incidence of overweight was 10·0 % in boys and 8·2 % in girls. Parental obesity, parental smoking and low physical activity were determinants of overweight incidence in boys, whereas paternal obesity increased the risk in girls. CONCLUSIONS: Treatment and prevention should address family and social determinants with a focus on physical activity and media use.

Hypophosphatemia as a sign of malnutrition in older hospitalized patients.

The relationship between hypophosphatemia (HP) and malnutrition in older hospitalized patients has received little attention. We sought to investigate this association among this population. The study participants were consecutively admitted to a geriatric acute care ward in six hospitals. Malnutrition screening was conducted by Mini Nutritional Assessment-Short Form. Patients were divided into two groups according to serum phosphate: HP (<0.68 mmol/l) and non-HP groups (>0.68 mmol/l). Of 335 participants, 7% of subjects had HP. Malnutrition or nutritional risk was present in 86 and 56% of participants with and without HP, respectively (P = 0.003). The analysis indicated 9.8, 86.4, 97.9 and 44.0% sensitivity, positive predictive value, specificity and negative predictive value of HP with regard to malnutrition, respectively. This study demonstrated that HP in older hospitalized patients is associated with malnutrition and may be used as an indicator of nutritional risk. Contrary, normal serum phosphate does not exclude being at nutritional risk.

Correction: Impact of energy turnover on the regulation of glucose homeostasis in healthy subjects.

Since publication of this article the authors noted that the legend for Table 1 was incomplete, as the subtitle was missing. The complete table should appear as given below. This has been corrected in both the PDF and HTML versions of the Article.

Impact of energy turnover on the regulation of glucose homeostasis in healthy subjects.

OBJECTIVE: Sedentary lifestyle increases the risk of type 2 diabetes. The aim of this study was to investigate the impact of different levels of energy turnover (ET; low, medium, and high level of physical activity and the corresponding energy intake) on glucose metabolism at zero energy balance, caloric restriction, and overfeeding. METHODS: Sixteen healthy individuals (13 men, 3 women, 25.1 ± 3.9 years, BMI 24.0 ± 3.2 kg/m2) participated in a randomized crossover intervention under metabolic ward conditions. Subjects passed 3 × 3 intervention days. Three levels of physical activity (PAL: low 1.3, medium 1.6, and high 1.8 achieved by walking at 4 km/h for 0, 3 × 55, or 3 × 110 min) were compared under three levels of energy balance (zero energy balance (EB): 100% of energy requirement (Ereq); caloric restriction (CR): 75% Ereq, and overfeeding (OF): 125% Ereq). Continuous interstitial glucose monitoring, C-peptide excretion, and HOMA-IR, as well as postprandial glucose and insulin were measured. RESULTS: Daylong glycemia and insulin secretion did not increase with higher ET at all conditions of energy balance (EB, CR, and OF), despite a correspondingly higher CHO intake (Δ low vs. high ET: +86 to 135 g of CHO/d). At CR, daylong glycemia (p = 0.02) and insulin secretion (p = 0.04) were even reduced with high compared with low ET. HOMA-IR was impaired with OF and improved with CR, whereas ET had no effect on fasting insulin sensitivity. A higher ET led to lower postprandial glucose and insulin levels under conditions of CR and OF. CONCLUSION: Low-intensity physical activity can significantly improve postprandial glycemic response of healthy individuals, independent of energy balance.

Association of different obesity indices with blood pressure and blood lipids in children and adolescents.

The aim of the present study was to compare individual associations of BMI, triceps skinfold (TSF), waist circumference (WC) and percentage fat mass (%FM) with blood pressure (BP) and blood lipids in children and adolescents. Cross-sectional data on BMI, TSF, WC, %FM as well as on BP, TAG and HDL were analysed in 4220 (BP) and 729 (lipids) 9-11-year-old children and 3174 (BP) and 536 (lipids) 13-16-year-old adolescents as part of the Kiel Obesity Prevention Study. All obesity indices were similarly associated with BP and blood lipids. In girls, WC had closer correlations to BP than BMI (systolic BP: 0.27 and 0.24 for BMI, 0.34 and 0.28 for WC in 9-11- and 13-16-year-olds). Subjects with an obesity index > or = 90th percentile had higher prevalences of elevated BP and blood lipids than subjects with a normal index. In children with normal BMI or WC, an additionally elevated second obesity index was associated with a 2.5-7.4-fold higher prevalence of high BP when compared with children with normal indices. In adolescents, an elevated WC plus an elevated second obesity index was associated with a 2.6-8.2-fold higher prevalence of high BP when compared with adolescents with an elevated WC plus a normal second index. We conclude that (i) both BMI and WC are appropriate to estimate CVD risk, (ii) the use of a second obesity index is recommended in children with normal BMI or normal WC as well as in adolescents with elevated WC and (iii) all obesity indices seemed to be appropriate for risk assessment.

Functional correlates of detailed body composition in healthy elderly subjects.

Methods of body composition analysis are now widely used to characterize health status, i.e., nutritional status, metabolic rates, and cardiometabolic risk factors. However, the functional correlates of individual body components have not been systematically analyzed. In this study, we have used a two-compartment model, which was assessed by air displacement plethysmography. Detailed body composition was measured by whole body magnetic resonance imaging in a healthy population of 40 Caucasians, aged 65-81 yr (20 men; body mass index range: 18.6-37.2 kg/m2). Physical, metabolic, as well as endocrine functions included pulmonary function, handgrip strength, gait speed, sit-to-stand test, physical activity, blood pressure, body temperature, resting energy expenditure (REE), liver and kidney functions (glomerular filtration rate), insulin sensitivity [homeostasis model assessment (HOMA)], plasma lipids, plasma leptin, testosterone, dehydroepiandrosterone, insulin-like growth factor I levels, thyroid status, vitamins, and inflammation. Individual body compartments were intercorrelated, e.g., skeletal muscle mass (SM) correlated with visceral adipose tissue ( r = 0.53) and kidneys ( r = 0.62). For the functional correlates, SM ( r = 0.58) and liver volume ( r = 0.63) were associated with REE, SM correlated with handgrip strength ( r = 0.57), and kidneys with glomerular filtration rate ( r = 0.57). While visceral adipose tissue correlated with HOMA ( r = 0.59), subcutaneous adipose tissue was related to plasma leptin levels ( r = 0.84). The subcutaneous adipose tissue-to-leptin relationship was moderated by inflammation increasing the explained variance of leptin levels by 4.0%. In linear regression analysis, detailed body composition explained variances in REE (75.0%), HOMA (41.0%), and leptin (78.0%) compared with a body mass index-based model (REE 16.0%, HOMA 31.0%, leptin 45.0%). In addition, detailed body composition explained 39.0% of the variance in kidney function. NEW & NOTEWORTHY BCA should be used to address specific body functions only. In clinical practice, there is need of a clear focus on the specific research question related to physical, metabolic, or endocrine functions.

Current Guidelines for Obesity Prevention in Childhood and Adolescence.

OBJECTIVE: Current guidelines for prevention of obesity in childhood and adolescence are discussed. METHODS: A literature search was performed in Medline via PubMed, and appropriate studies were analyzed. RESULTS: Programs to prevent childhood obesity have so far remained mainly school-based and effects have been limited. Analyses by age group show that prevention programs have the best results in younger children (<12 years). Evidence-based recommendations for pre-school- and early school-aged children indicate the need for interventions that address parents and teachers alike. During adolescence, school-based interventions proved most effective when adolescents were addressed directly. To date, obesity prevention programs have mainly focused on behavior-oriented prevention. Recommendations for community- or environment-based prevention have been suggested by the German Alliance of Noncommunicable Diseases and include a minimum of 1 h of physical activity at school, promotion of healthy food choices by taxing unhealthy foods, mandatory standards for meals at kindergartens and schools as well as a ban on unhealthy food advertisement aimed at children. CONCLUSION: Behavior-oriented prevention programs showed only limited long-term effects. Certain groups at risk for the development of obesity are not reached effectively by current programs. Although universally valid conclusions cannot be drawn given the heterogeneity of available studies, clearly combining behavior-based programs with community-based prevention to counteract an 'obesogenic environment' is crucial for sustainable success of future obesity prevention programs.

Beyond BMI: Conceptual Issues Related to Overweight and Obese Patients.

BMI is widely used as a measure of weight status and disease risks; it defines overweight and obesity based on statistical criteria. BMI is a score; neither is it biologically sound nor does it reflect a suitable phenotype worthwhile to study. Because of its limited value, BMI cannot provide profound insight into obesity biology and its co-morbidity. Alternative assessments of weight status include detailed phenotyping by body composition analysis (BCA). However, predicting disease risks, fat mass, and fat-free mass as assessed by validated techniques (i.e., densitometry, dual energy X ray absorptiometry, and bioelectrical impedance analysis) does not exceed the value of BMI. Going beyond BMI and descriptive BCA, the concept of functional body composition (FBC) integrates body components into regulatory systems. FBC refers to the masses of body components, organs, and tissues as well as to their inter-relationships within the context of endocrine, metabolic and immune functions. FBC can be used to define specific phenotypes of obesity, e.g. the sarcopenic-obese patient. Well-characterized obesity phenotypes are a precondition for targeted research (e.g., on the genomics of obesity) and patient-centered care (e.g., adequate treatment of individual obese phenotypes such as the sarcopenic-obese patient). FBC contributes to a future definition of overweight and obesity based on physiological criteria rather than on body weight alone.

Metabolic adaptation to caloric restriction and subsequent refeeding: the Minnesota Starvation Experiment revisited.

BACKGROUND: Adaptive thermogenesis (AT) is the fat-free mass (FFM)-independent reduction of resting energy expenditure (REE) to caloric restriction (CR). AT attenuates weight loss and favors weight regain. Its variance, dynamics, and control remain obscure. OBJECTIVES: Our aims were to address the variance and kinetics of AT, its associations with body composition in the context of endocrine determinants, and its effect on weight regain. DESIGN: Thirty-two nonobese men underwent sequential overfeeding (1 wk at +50% of energy needs), CR (3 wk at -50% of energy needs), and refeeding (2 wk at +50% of energy needs). AT and its determinants were measured together with body composition as assessed with the use of quantitative magnetic resonance, whole-body MRI, isotope dilution, and nitrogen and fluid balances. RESULTS: Changes in body weight were +1.8 kg (overfeeding), -6.0 kg (CR), and +3.5 kg (refeeding). CR reduced fat mass and FFM by 114 and 159 g/d, respectively. Within FFM, skeletal muscle (-5%), liver (-13%), and kidneys (-8%) decreased. CR also led to reductions in REE (-266 kcal/d), respiratory quotient (-15%), heart rate (-14%), blood pressure (-7%), creatinine clearance (-12%), energy cost of walking (-22%), activity of the sympathetic nervous system (SNS) (-38%), and plasma leptin (-44%), insulin (-54%), adiponectin (-49%), 3,5,3'-tri-iodo-thyronine (T3) (-39%), and testosterone (-11%). AT was 108 kcal/d or 48% of the decrease in REE. Changes in FFM composition explained 36 kcal, which left 72 kcal/d for true AT. The decrease in AT became significant at ≤3 d of CR and was related to decreases in insulin secretion (r = 0.92, P < 0.001), heart rate (r = 0.60, P < 0.05), creatinine clearance (r = 0.79, P < 0.05), negative fluid balance (r = 0.51, P < 0.01), and the free water clearance rate (r = -0.90, P < 0.002). SNS activity and plasma leptin, ghrelin, and T3 and their changes with CR were not related to AT. CONCLUSION: During early weight loss, AT is associated with a fall in insulin secretion and body fluid balance. This trial was registered at clinicaltrials.gov as NCT01737034.