Publications by authors named "Anja Bosy-Westphal"

132 Publications

Are metabolic adaptations to weight changes an artefact?

Am J Clin Nutr 2021 Jun 16. Epub 2021 Jun 16.

Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.

Background: Adaptive thermogenesis (AT) is currently defined as the fat-free mass (FFM)-independent change in resting energy expenditure (REE) in response to caloric restriction (CR) or overfeeding (OF). So far, the impact of changes in the anatomical and molecular composition of FFM on AT has not been addressed.

Objectives: To assess the impact of changes in FFM composition on AT.

Methods: FFM was assessed in 32 healthy young men during controlled 21-d CR and 14 d of subsequent OF. Anatomical (i.e., the organ/tissue level) and molecular (i.e., water, mineral, and protein content and thus body density) composition of FFM were characterized. REE was measured by indirect calorimetry.

Results: With CR, body weight and REE decreased by 4.2 ± 0.9 kg and 173 ± 107 kcal/d, respectively, with corresponding increases of 3.5 ± 1.2 kg and 194 ± 110 kcal/d during OF (P < 0.001 for all changes). Changes in FFM explained 56.7% and 66.7% of weight loss and weight gain, respectively. Weight changes were associated with changes in various anatomical (i.e., masses of skeletal muscle, liver, kidneys, and brain) and molecular components (total body water, protein, and bone minerals) of FFM. After adjustments for changes in FFM only, AT was 116 ± 127 (P < 0.001) and 27 ± 115 kcal/d (NS) with CR and OF, respectively. Adjustments for FFM and its anatomical and molecular composition reduced AT in response to CR to 83 ± 116 and 122 ± 123 kcal/d (P < 0.05 and P < 0.001) whereas during OF, AT became significant at 87 ± 146 kcal/d (anatomical; P < 0.05) and 86 ± 118 kcal/d (molecular; P < 0.001).

Conclusions: Adjusting changes in REE with under- and overfeeding for the corresponding changes in the anatomical and molecular composition of FFM decreased AT after CR and increased AT after OF, but overall adjusted AT was likely not large enough in magnitude to be able to prevent weight loss or resist weight gain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ajcn/nqab184DOI Listing
June 2021

Postprandial dynamics and response of fibroblast growth factor 21 in older adults.

Clin Nutr 2021 Jun 27;40(6):3765-3771. Epub 2021 Apr 27.

German Institute of Human Nutrition, Potsdam-Rehbrücke, Department of Nutrition and Gerontology, Nuthetal, Germany; University of Potsdam, Institute of Nutritional Science, Potsdam, Germany; Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Department of Geriatrics, Berlin, Germany. Electronic address:

Background & Aims: Fibroblast growth factor 21 (FGF21) plays a pivotal role in glucose and lipid metabolism and has been proposed as a longevity hormone. However, elevated plasma FGF21 concentrations are paradoxically associated with mortality in higher age and little is known about the postprandial regulation of FGF21 in older adults. In this parallel group study, we investigated postprandial FGF21 dynamics and response in older (65-85 years) compared to younger (18-35 years) adults following test meals with varying macronutrient composition.

Methods: Participants (n = 60 older; n = 60 younger) were randomized to one of four test meals: dextrose, high carbohydrate (HC), high fat (HF) or high protein (HP). Blood was drawn before and 15, 30, 60, 120, 240 min after meal ingestion. Postprandial dynamics were evaluated using repeated measures ANCOVA. FGF21 response was assessed by incremental area under the curve.

Results: Fasting FGF21 concentrations were significantly higher in older adults. FGF21 dynamics were affected by test meal (p < 0.001) and age (p = 0.013), when adjusted for BMI and fasting FGF21. Postprandial FGF21 concentrations steadily declined over 240 min in both age groups after HF and HP, but not after dextrose or HC ingestion. At 240 min, FGF21 concentrations were significantly higher in older than in younger adults following dextrose (133 pg/mL, 95%CI: 103, 172 versus 91.2 pg/mL, 95%CI: 70.4, 118; p = 0.044), HC (109 pg/mL, 95%CI: 85.1, 141 versus 70.3 pg/mL, 95%CI: 55.2, 89.6; p = 0.014) and HP ingestion (45.4 pg/mL, 95%CI: 34.4, 59.9 versus 27.9 pg/mL 95%CI: 20.9, 37.1; p = 0.018). FGF21 dynamics and response to HF were similar for both age groups.

Conclusions: The age-specific differences in postprandial FGF21 dynamics and response in healthy adults, potentially explain higher FGF21 concentrations in older age. Furthermore, there appears to be a significant impact of acute and recent protein intake on FGF21 secretion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clnu.2021.04.037DOI Listing
June 2021

Boron Contents of German Mineral and Medicinal Waters and Their Bioavailability in Drosophila melanogaster and Humans.

Mol Nutr Food Res 2021 Jun 1:e2100345. Epub 2021 Jun 1.

Institute of Human Nutrition and Food Science, University of Kiel, Kiel, Germany.

Scope: Boron is a trace element that naturally occurs in soil, making mineral and medicinal water important contributors to overall intake. Thus, in a systematic screening, the mean boron concentrations of 381 German mineral and medicinal waters are determined.

Methods And Results: Boron concentrations in mineral and medicinal waters are analyzed by inductively coupled mass spectrometry (ICP-MS). Highest boron values find in waters from the southwest of Germany. The boron content of the waters is positively correlated with the concentration of most other analyzed bulk elements, including calcium, potassium, magnesium, and sodium. Mineral waters with either low (7.9 µg L ), medium (113.9 µg L ), or high (2193.3 µg L ) boron content are chosen for boron exposure experiments in fruit flies (Drosophila melanogaster) and humans. In flies, boron-rich mineral water significantly increases boron accumulation, with the accumulation predominantly occurring in the exoskeleton. In humans, serum boron and 24-h urinary boron excretion significantly increase only in response to the intake of boron-rich mineral water.

Conclusion: Overall, the current data demonstrate that mineral and medicinal waters vary substantially in the content of boron and that boron-rich mineral water can be used to elevate the boron status, both in flies and humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mnfr.202100345DOI Listing
June 2021

Impact of Energy Turnover on the Regulation of Energy and Macronutrient Balance.

Obesity (Silver Spring) 2021 Jul 17;29(7):1114-1119. Epub 2021 May 17.

Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Christian-Albrechts University, Kiel, Germany.

Energy turnover, defined as the average daily total metabolic rate, can be normalized for basal metabolic rate in order to compare physical activity level between individuals, whereas normalization of energy turnover for energy intake (energy flux) allows investigation of its impact on regulation of energy partitioning independent of energy balance. Appetite sensations better correspond to energy requirements at a high compared with a low energy turnover. Adaptation of energy intake to habitual energy turnover may, however, contribute to the risk of weight gain associated with accelerated growth, pregnancy, detraining in athletes, or after weight loss in people with obesity. The dose-response relationship between energy turnover and energy intake as well as the metabolic effects of energy turnover varies with the habitual level of physical activity and the etiology of energy turnover (e.g., cold-induced thermogenesis, growth, or lactation; aerobic vs. anaerobic exercise). Whether a high energy turnover due to physical activity or exercise may compensate for adverse effects of overfeeding or an unhealthy diet needs to be further investigated using the concept of energy flux. In summary, the beneficial effects of a high energy turnover on regulation of energy and macronutrient balance facilitate the prevention and treatment of obesity and associated metabolic risk.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/oby.23133DOI Listing
July 2021

Impact of Protein Intake during Weight Loss on Preservation of Fat-Free Mass, Resting Energy Expenditure, and Physical Function in Overweight Postmenopausal Women: A Randomized Controlled Trial.

Obes Facts 2021 11;14(3):259-270. Epub 2021 May 11.

Fulda University of Applied Sciences, Fulda, Germany.

Introduction: Weight loss in old age increases the risk of sarcopenia caused by the age-related reduction of fat-free mass (FFM). Due to the strong correlation between FFM and resting energy expenditure (REE), the maintenance of this must also be considered. Besides, the physical function (PF) must be maintained.

Objective: The impact of protein intake on changes in FFM, REE, and PF during weight loss in overweight postmenopausal women was investigated.

Methods: Fifty-four postmenopausal women (BMI 30.9 ± 3.4; age 59 ± 7 years) were randomized into 2 groups receiving energy-restricted diets with either 0.8 g (normal protein; NP) or 1.5 g protein/kg body weight (high protein; HP) for 12 weeks, followed by a 6-month follow-up phase with an ad libitum food intake. FFM, REE, and PF (strength, endurance, and balance) were measured at baseline, after weight loss, and after follow-up.

Results: Forty-six women completed the weight loss intervention and 29 were followed up. The weight loss was -4.6 ± 3.6 kg (HP) and -5.2 ± 3.4 kg (NP; both p < 0.001) and the weight regain during follow-up was 1.3 ± 2.8 kg (HP; p = 0.03) and 0.4 ± 2.5 kg (NP; p = 0.39), with no differences between groups. Similar decreases in FFM (-0.9 ± 1.1 [HP] vs. -1.0 ± 1.3 kg [NP]) and REE (-862 ± 569 [HP] vs. -1,000 ± 561 kJ [NP]; both p < 0.001) were observed in both groups. During follow-up, no changes in FFM were detected in either group, whereas in the NP group the REE increased again (+138 ± 296; p = 0.02). The main determinants of FFM loss were the energy deficit and the speed of weight loss. In the NP group, the Short Physical Performance Battery score improved with weight loss (+0.6 ± 0.8; p < 0.001) and handgrip strength decreased (-1.7 ± 3.4 kg; p < 0.001), whereas no changes were observed in the HP group.

Conclusions: An HP weight-loss diet without exercise had no impact on preservation of FFM and REE but may help to maintain muscle strength in postmenopausal women.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000514427DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8255642PMC
May 2021

Does adaptive thermogenesis occur after weight loss in adults? A systematic review.

Br J Nutr 2021 Mar 25:1-19. Epub 2021 Mar 25.

Exercise and Health Laboratory, CIPER, Faculdade Motricidade Humana, Universidade de Lisboa, Estrada da Costa, Cruz-Quebrada 1499-002, Portugal.

Adaptive thermogenesis (AT) has been proposed to be a compensatory response that may resist weight loss (WL) and promote weight regain. This systematic review examined the existence of AT in adults after a period of negative energy balance (EB) with or without a weight stabilisation phase. Studies published until 15 May 2020 were identified from PubMed, Cochrane Library, EMBASE, MEDLINE, SCOPUS and Web of Science. Inclusion criteria included statistically significant WL, observational with follow-up or experimental studies, age > 18y, sample size ≥10 participants, intervention period ≥ 1week, published in English, objective measures of total daily energy expenditure (EE) (TDEE), resting EE (REE) and sleeping EE(SEE). The systematic review was registered at PROSPERO (2020 CRD42020165348). A total of thirty-three studies comprising 2528 participants were included. AT was observed in twenty-seven studies. Twenty-three studies showed significant values for AT for REE (82·8 %), four for TDEE (80·0 %) and two for SEE (100 %). A large heterogeneity in the methods used to quantify AT and between subjects and among studies regarding the magnitude of WL and/or of AT was reported. Well-designed studies reported lower or non-significant values for AT. These findings suggest that although WL may lead to AT in some of the EE components, these values may be small or non-statistically significant when higher-quality methodological designs are used. Furthermore, AT seems to be attenuated, or non-existent, after periods of weight stabilisation/neutral EB. More high-quality studies are warranted not only to disclose the existence of AT but also to understand its clinical implications on weight management outcomes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0007114521001094DOI Listing
March 2021

[Diet and Nutrition in the Prevention of Non-Communicable Diseases (NCD)].

Dtsch Med Wochenschr 2021 Mar 18;146(6):389-397. Epub 2021 Mar 18.

Today, more than 50 % of adults in Germany are overweight, 20 million people are obese and 10 to 30 % suffer from non-communicable diseases (NCD). Unhealthy dietary patterns contribute to NCD, thus, NCD are at least partly avoidable. During the last decades nutrition research has changed from nutrients to foods identifying healthy food patterns characterizing healthy diets, e. g., Mediterranean diet, DASH diet and/or the New Nordic Diet. Scientifically, these diets have been shown to be effective strategies of primary and secondary prevention of NCD. Based on this evidence prevention of NCD is now urgently needed at the population level. However, effective public health strategies of prevention and health promotion go beyond daily medical practice and require re-thinking of our food system within a greater context of our environment and climate. To become sustainable, strategies and measures of behavior prevention addressing individuals have to be extended to measures against the obesogenic environment and its systemic drivers within our food system. Thus, social and political changes are needed for a better future health of the nation. Physicians may take the leadership to be prepared to add to a whole of society approach of prevention and health promotion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1248-5539DOI Listing
March 2021

Resting Energy Expenditure: From Cellular to Whole-Body Level, a Mechanistic Historical Perspective.

Obesity (Silver Spring) 2021 03;29(3):500-511

Department of Human Nutrition and Food Science, Christian-Albrecht University of Kiel, Kiel, Germany.

The basis of heat generated by the human body has been a source of speculation and research for more than 2,000 years. Basal heat production, now usually referred to as resting energy expenditure (REE), is currently recognized as deriving from biochemical reactions at subcellular and cellular levels that are expressed in the energy expended by the body's 78 organs and tissues. These organs and tissues, and the 11 systems to which they belong, influence body size and shape. Connecting these subcellular-/cellular-level reactions to organs and tissues, and then on to body size and shape, provides a comprehensive understanding of individual differences in REE, a contemporary topic of interest in obesity research and clinical practice. This review critically examines these linkages, their association with widely used statistical and physiological REE prediction formulas, and often-unappreciated aspects of measuring basal heat production in humans.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/oby.23090DOI Listing
March 2021

Diagnosis of obesity based on body composition-associated health risks-Time for a change in paradigm.

Obes Rev 2021 03 21;22 Suppl 2:e13190. Epub 2021 Jan 21.

Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.

Traditional diagnosis and understanding of the pathophysiology of obesity are based on excessive fat storage due to a chronically positive energy balance characterized by body mass index (BMI). Quantitative and qualitative analysis of lean and adipose tissue compartments by body composition analysis reveals that characterization of obesity as "overfat" does not facilitate a comprehensive understanding of obesity-associated health risk. Instead of being related to fat mass, body composition characteristics underlying BMI-associated prognosis may depend (i) on accelerated growth by a gain in lean mass or fat-free mass (FFM) in children with early BMI rebound or adolescents with early puberty; (ii) on a low muscle mass in aging, associated chronic disease, or severe illness; and (iii) on impaired adipose tissue expandability with respect to cardiometabolic risk. It is therefore time to call the adipocentric paradigm of obesity into question and to avoid the use of BMI and body fat percentage. By contrast, obesity should be seen in face of a limited FFM/muscle mass together with a limited capacity of fat storage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/obr.13190DOI Listing
March 2021

Nutritional Recommendations for People with Type 1 Diabetes Mellitus.

Exp Clin Endocrinol Diabetes 2020 Dec 29. Epub 2020 Dec 29.

ZIEL - Institute for Food & Health, Technical University Munich, Munich, Germany.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1284-6036DOI Listing
December 2020

Family and Lifestyle Factors Mediate the Relationship between Socioeconomic Status and Fat Mass in Children and Adolescents.

Obes Facts 2020 Dec 15;13(6):596-607. Epub 2020 Dec 15.

Human Nutrition, Institute of Human Nutrition and Food Science, Christian-Albrechts University, Kiel, Germany,

Socioeconomic status (SES) is strongly associated with childhood overweight. The underlying mechanism and the role of family and lifestyle factors as potential mediators of this relationship remain, however, unclear. Cross-sectional data of 4,772 girls and boys aged 5-16 years from the Kiel Obesity Prevention Study were considered in mediation analyses. Fat mass (FM) was assessed by bioelectrical impedance analysis and converted into a percent FM SD score (FM%-SDS). SES was defined by the parental educational level, classified as low, middle, or high. Characteristics of family and lifestyle factors were obtained via validated questionnaires and considered as mediators. In 3 different age groups, the product-of-coefficients method was used to examine age-specific mediator effects on the relationship between SES and FM%-SDS (c = total effects) and their ratio to total effects, adjusted for age, sex, puberty, and nationality. The prevalence of overweight was 6.9%. In all age groups, SES was inversely associated with FM%-SDS as follows: 5-7 years, c1 = -0.11 (95% CI -0.19 to -0.03); 9-11 years, c2 = -0.21 (95% CI -0.27 to -0.14); and 13-16 years, c3 = -0.23 (95% CI -0.28 to -0.17). The relationship between SES and FM%-SDS was fully (5-7 and 9-11 years) and partly (13-16 years) mediated by similar and age-specific mediators, including parental BMI, parental smoking habits, media consumption, physical activity, and shared meals. Overall, these variables resulted in a total mediating effect of 77.8% (5-7 years), 82.4% (9-11 years), and 70.6% (13-16 years). Consistent for both sexes, the relationship between SES and FM%-SDS was therefore mediated by parental weight status, risk-related behavior within families, and children's and adolescents' lifestyle factors. Strategies for obesity prevention, which are predominantly targeted at socially disadvantaged groups, should therefore address the family environment and lifestyle factors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000511927DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7802469PMC
December 2020

From a "Metabolomics fashion" to a sound application of metabolomics in research on human nutrition.

Eur J Clin Nutr 2020 12 21;74(12):1619-1629. Epub 2020 Oct 21.

Institute of Human Nutrition and Food Science, Faculty of Agriculture and Food Sciences, Christian-Albrecht-University Kiel, Kiel, Germany.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41430-020-00781-6DOI Listing
December 2020

Circulating sDPP-4 is Increased in Obesity and Insulin Resistance but Is Not Related to Systemic Metabolic Inflammation.

J Clin Endocrinol Metab 2021 Jan;106(2):e592-e601

Division of Endocrinology, Diabetes and Clinical Nutrition, Department of Medicine 1, University of Kiel, Kiel, Germany.

Context: Dipeptidylpeptidase (DPP)-4 is a key regulator of the incretin system. It exists in a membrane-bound form and a soluble form (sDPP-4). Initial human studies suggested sDPP-4 to be an adipokine involved in metabolic inflammation. However, recent mechanistic data in genetically modified mice has questioned these findings.

Objectives: We examined circulating sDPP-4 in a cohort of n = 451 humans with different metabolic phenotypes and during 3 different weight loss interventions (n = 101) to further clarify its role in human physiology and metabolic diseases.

Design: sDPP-4 serum concentrations were measured by enzyme-linked immunosorbent assay and related to several phenotyping data including gut microbiome analysis.

Results: sDPP-4 increased with age and body weight and was positively associated with insulin resistance and hypertriglyceridemia but was reduced in manifest type 2 diabetes. In addition, we found reduced serum concentrations of sDPP-4 in subjects with arterial hypertension. In contrast to earlier reports, we did not identify an association with systemic markers of inflammation. Impaired kidney and liver functions significantly altered sDPP-4 concentrations while no relation to biomarkers for heart failure was observed. Having found increased levels of sDPP-4 in obesity, we studied surgical (gastric bypass and sleeve gastrectomy) and nonsurgical interventions, revealing a significant association of sDPP-4 with improvement of liver function tests but not with changes in body weight.

Conclusions: Our data suggest that sDPP-4 is related to hepatic abnormalities in obesity rather than primarily functioning as an adipokine and that sDPP-4 is implicated both in glucose and in lipid metabolism, but not fundamentally in systemic inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/clinem/dgaa758DOI Listing
January 2021

Configuration of bioelectrical impedance measurements affects results for phase angle.

Med Eng Phys 2020 10 30;84:10-15. Epub 2020 Jul 30.

Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität Kiel, Düsternbrooker Weg 17, 24105 Kiel, Germany.

Objective: Phase angle (PhA) obtained by bioelectrical impedance analysis is a well-established predictor of malnutrition that reflects the amount and quality of soft tissue. However, PhA results may depend on configurations of the measurement that differ between devices. The aim was to analyze differences between devices for supine and standing measurements.

Approach: In a cross-sectional study, differences in PhA were analyzed comparing supine vs. standing positions, metal vs. adhesive electrodes and the right vs. left side of the body in 302 multi-ethnic adults (18-65y) and 1298 Mexican children and adolescents (4-20y).

Main Results: PhA was higher in supine than in standing position (from 0.71°±0.22° in children to 0.97°±0.25° in adults; all p < 0.001) with approximately fifty percent of observed differences explained by electrode placement. PhA differences increased with increasing PhA (r = 0.419) and decreased with age (r = -0.346) in adults, but increased with PhA (r = 0.677), age (r = 0.752) and height (r = 0.737) in children (all p <0.001). In adults, PhA was higher on the right side of the body (standing 0.18°±0.17°; supine 0.36°±0.33°; p <0.001).

Significance: Phase angle results are influenced by posture and electrode placement. Measurement configuration must be considered when phase angle values are compared between different devices or with literature values.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.medengphy.2020.07.021DOI Listing
October 2020

Reference Values for Skeletal Muscle Mass - Current Concepts and Methodological Considerations.

Nutrients 2020 Mar 12;12(3). Epub 2020 Mar 12.

Institute for Human Nutrition and Food Science, Christian-Albrechts-University Kiel, 24105 Kiel, Germany.

Assessment of a low skeletal muscle mass (SM) is important for diagnosis of ageing and disease-associated sarcopenia and is hindered by heterogeneous methods and terminologies that lead to differences in diagnostic criteria among studies and even among consensus definitions. The aim of this review was to analyze and summarize previously published cut-offs for SM applied in clinical and research settings and to facilitate comparison of results between studies. Multiple published reference values for discrepant parameters of SM were identified from 64 studies and the underlying methodological assumptions and limitations are compared including different concepts for normalization of SM for body size and fat mass (FM). Single computed tomography or magnetic resonance imaging images and appendicular lean soft tissue by dual X-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA) are taken as a valid substitute of total SM because they show a high correlation with results from whole body imaging in cross-sectional and longitudinal analyses. However, the random error of these methods limits the applicability of these substitutes in the assessment of individual cases and together with the systematic error limits the accurate detection of changes in SM. Adverse effects of obesity on muscle quality and function may lead to an underestimation of sarcopenia in obesity and may justify normalization of SM for FM. In conclusion, results for SM can only be compared with reference values using the same method, BIA- or DXA-device and an appropriate reference population. Limitations of proxies for total SM as well as normalization of SM for FM are important content-related issues that need to be considered in longitudinal studies, populations with obesity or older subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu12030755DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146130PMC
March 2020

Postpartum Weight Retention in Women With Obesity.

J Clin Endocrinol Metab 2020 06;105(6)

Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/clinem/dgaa119DOI Listing
June 2020

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

Curr Diab Rep 2019 11 4;19(11):108. Epub 2019 Nov 4.

Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität zu Kiel, Düsternbrooker Weg 17-19, D-24105, Kiel, Germany.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11892-019-1221-7DOI Listing
November 2019

Impact of energy turnover on fat balance in healthy young men during energy balance, caloric restriction and overfeeding.

Br J Nutr 2019 Oct 11:1-27. Epub 2019 Oct 11.

Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Kiel, Germany.

Body weight control is thought to be improved when physical activity and energy intake are both high (high energy turnover). The aim of this study was to investigate the short-term impact of energy turnover (ET) on fat balance during zero energy balance, caloric restriction and overfeeding. In a randomized crossover study, 9 healthy men (BMI: 23.0 ±2.1 kg/m2, 26.6 ±3.5 y) passed 3x3 days in a metabolic chamber: 3 levels of ET (low, medium and high; physical activity level = 1.3-1.4, 1.5-1.6 and 1.7-1.8) were performed at zero energy balance (EB), caloric restriction (CR), and overfeeding (OF) (100%, 75%, 125% of individual energy requirement). Different levels of ET were obtained by walking (4 km/h) on a treadmill (0, 165, 330 min). 24-h macronutrient oxidation and relative macronutrient balance (oxidation relative to intake) were calculated and free fatty acids, 24-h insulin and catecholamine secretion were analyzed as determinants of fat oxidation. During EB and OF, 24-h fat oxidation increased with higher ET. This resulted in a higher relative fat balance at medium ET (EB: +17%, OF: +14%) and high ET (EB: +23%, OF: +17%) compared to low ET (all p<0.05). In contrast, CR led to a stimulation of 24-h fat oxidation irrespective of ET (no differences in relative fat balance between ET levels, p>0.05). In conclusion, under highly controlled conditions a higher energy turnover improved relative fat balance in young healthy men during overfeeding and energy balance compared to a sedentary state.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0007114519002551DOI Listing
October 2019

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

Nutr Diabetes 2019 Oct 7;9(1):27. Epub 2019 Oct 7.

Institute of Human Nutrition and Food Science, Christian-Albrechts University of Kiel, Kiel, Germany.

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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41387-019-0094-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6779747PMC
October 2019

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

Nutr Diabetes 2019 08 8;9(1):22. Epub 2019 Aug 8.

Institute of Human Nutrition and Food Science, Christian-Albrechts University of Kiel, Kiel, Germany.

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/m) 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.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41387-019-0089-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6687696PMC
August 2019

Obesity Tissue: Composition, Energy Expenditure, and Energy Content in Adult Humans.

Obesity (Silver Spring) 2019 09 19;27(9):1472-1481. Epub 2019 Jul 19.

Pennington Biomedical Research Center, LSU System, Baton Rouge, Louisiana, USA.

Objective: Chronic positive energy balance leads to obesity, and the "excess" weight is usually described as consisting solely of adipose tissue (AT) or its two components, fat and fat-free mass (nonfat cell mass, extracellular fluid). This study aimed to clarify the nature of "obesity" tissue.

Methods: A total of 333 adults had AT, skin, skeletal muscle, bone, heart, liver, kidney, spleen, brain, and residual mass measured or derived using magnetic resonance imaging and dual-energy x-ray absorptiometry. First, associations between these components and AT were examined by developing multiple regression models. Next, obesity-tissue composition was developed by deriving mean component mass differences between participant groups with normal weight (BMI < 25 kg/m ) and those with obesity (BMI > 29.9 kg/m ); respective resting energy expenditures and metabolizable energy and protein contents were calculated.

Results: AT significantly predicted organ-tissue mass in 17 of 18 multiple regression models. In addition to AT and skeletal muscle, the following associations were found: skin, liver, and bone were main contributors to obesity-tissue composition; liver, kidneys, and heart to resting energy expenditure; and skin, liver, and bone to metabolizable energy and protein contents. A pronounced sexual dimorphism was present in all three models.

Conclusions: Obesity is characterized not only by excess AT but by increases in the masses of other "companion" organs and tissues and their related metabolic properties.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/oby.22557DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6707863PMC
September 2019

Appetite Control Is Improved by Acute Increases in Energy Turnover at Different Levels of Energy Balance.

J Clin Endocrinol Metab 2019 10;104(10):4481-4491

Department of Human Nutrition, Institute of Human Nutrition and Food Sciences, Christian-Albrechts University, Kiel, Germany.

Background: Weight control is hypothesized to be improved when physical activity and energy intake are both high [high energy turnover (ET)].

Objective: The impact of three levels of ET on short-term appetite control is therefore investigated at fixed levels of energy balance.

Design: In a randomized crossover trial, 16 healthy adults (25.1 ± 3.9 y of age; body mass index, 24.0 ± 3.2 kg/m2) spent three daylong protocols for four times in a metabolic chamber. Four conditions of energy balance (ad libitum energy intake, zero energy balance, -25% caloric restriction, and +25% overfeeding) were each performed at three levels of ET (PAL 1.3 low, 1.6 medium, and 1.8 high ET; by walking on a treadmill). Levels of appetite hormones ghrelin, GLP-1, and insulin (total area under the curve) were measured during 14 hours. Subjective appetite ratings were assessed by visual analog scales.

Results: Compared with high ET, low ET led to decreased GLP-1 (at all energy balance conditions: P < 0.001) and increased ghrelin concentrations (caloric restriction and overfeeding: P < 0.001), which was consistent with higher feelings of hunger (zero energy balance: P < 0.001) and desire to eat (all energy balance conditions: P < 0.05) and a positive energy balance during ad libitum intake (+17.5%; P < 0.001).

Conclusion: Appetite is regulated more effectively at a high level of ET, whereas overeating and consequently weight gain are likely to occur at low levels of ET. In contrast to the prevailing concept of body weight control, the positive impact of physical activity is independent from burning up more calories and is explained by improved appetite sensations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2019-01164DOI Listing
October 2019

Limitations of Fat-Free Mass for the Assessment of Muscle Mass in Obesity.

Obes Facts 2019 27;12(3):307-315. Epub 2019 May 27.

Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität Kiel, Kiel, Germany,

Background: A high amount of adipose tissue limits the accuracy of methods for body composition analysis in obesity.

Objectives: The aim was to quantify and explain differences in fat-free mass (FFM) (as an index of skeletal muscle mass, SMM) measured with bioelectrical impedance analysis (BIA), dual energy X-ray absorptiometry (DXA), air displacement plethysmography (ADP), and deuterium dilution in comparison to multicompartment models, and to improve the results of BIA for obese subjects.

Methods: In 175 healthy subjects (87 men and 88 women, BMI 20-43.3 kg/m2, 18-65 years), FFM measured by these methods was compared with results from a 3- (3C) and a 4-compartment (4C) model. FFM4C was compared with SMM measured by magnetic resonance imaging.

Results: BIA and DXA overestimated and ADP underestimated FFM in comparison to 3C and 4C models with increasing BMI (all p < 0.001). -Differences were largest for DXA. In obesity, BIA results were improved: valuecorrected = -valueuncorrected - a(BMI - 30 kg/m2), a = 0.256 for FFM and a = 0.298 for SMM. SMM accounts for 45% of FFM in women and 49% in men.

Conclusions: In obesity, the use of FFM is limited by a systematic error of reference methods. In addition, SMM accounts for about 50% of FFM only. Corrected measurement of SMM by BIA can overcome these drawbacks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1159/000499607DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6696776PMC
February 2020

Lithium-Rich Mineral Water is a Highly Bioavailable Lithium Source for Human Consumption.

Mol Nutr Food Res 2019 May 3:e1900039. Epub 2019 May 3.

Kiel University, Institute of Human Nutrition and Food Science, Devision of Food Science, 24118, Kiel, Germany.

Scope: Lithium is an important trace element in human nutrition and medicine. Mineral and medicinal waters may represent a significant source of dietary lithium intake.

Methods And Results: The lithium concentration of 360 German mineral and 21 medicinal waters is determined. Based on a systematic screening, three different mineral waters exhibiting low (1.7 µg L ), medium (171 µg L ), and high lithium (1724 µg L ) concentrations are chosen for an acute bioavailability study in male healthy volunteers. In Germany, a north-east to south-west gradient of analyzed lithium concentrations is observed in the 381 tested waters. The lithium concentration in the water is significantly correlated with its sodium (r = 0. 810), potassium (r = 0.716), and magnesium (r = 0.361), but not with its calcium concentration. In a randomized cross-over trial, volunteers (n = 3×10 each) drink 1.5 L of the respective mineral waters, and lithium concentrations in serum and urine are monitored over 24 h. Consumption of the mineral waters with a medium and high lithium content results in a dose-dependent response in serum lithium concentrations and total urinary lithium excretion.

Conclusion: Lithium-rich mineral and medicinal waters may be an important and highly bioavailable lithium source for human consumption.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mnfr.201900039DOI Listing
May 2019

Representative body composition percentiles from bioelectrical impedance analyses among children and adolescents. The MoMo study.

Clin Nutr 2019 12 4;38(6):2712-2720. Epub 2018 Dec 4.

Institute of Sports and Sports Science, Karlsruhe Institute of Technology, Karlsruhe, Germany.

Background & Aims: With high prevalence of overweight and obesity in developed countries, the assessment of body composition in children and adolescents is of growing interest. The aim of this study was (i) to provide up-to-date population wide percentiles for meaningful diagnostic bioelectrical impedance outcome parameters and (ii) to specify reference values for these measures in a normal weight subpopulation.

Methods: A representative nationwide sample of 4 to 24-year-old children and adolescents (n = 3593) was drawn out of 167 primary sample points across Germany from 2009 to 2012 (Motorik-Modul study wave 1). Fat free mass index (FFMI), fat mass index (FMI), body cell mass index (BCMI) and phase angle (PA) were derived from four electrodes 50 kHz bioelectrical impedance analyses. Sex-specific percentiles were calculated using the LMS-method for the total study population and a normal weight subsample (defined according to the international BMI-standard by Cole).

Results: Percentile curves for body composition parameters are similar between boys and girls until puberty. Subsequently, girls show a higher FMI than boys, and boys increase their FFM, BCM, and PA time-shifted, in that order. Differences in FMI between the overall and the normal weight sample increase with age, showing an age-dependent prevalence for overweight and obesity among the representative German sample.

Conclusions: Results from the normal weight sample can be used as reference values to define a healthy body composition. Differences in body composition between the representative German sample and the normal weight subsample reveal a high prevalence of elevated fat mass in the population of children and adolescents living in Germany.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.clnu.2018.11.026DOI Listing
December 2019

Thanks for opening an overdue discussion on GWAS of BMI: a reply to Prof. Speakman et al.

Int J Obes (Lond) 2019 01 27;43(1):217-218. Epub 2018 Nov 27.

Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41366-018-0264-1DOI Listing
January 2019

Ethnic differences in fat and muscle mass and their implication for interpretation of bioelectrical impedance vector analysis.

Appl Physiol Nutr Metab 2019 Jun 24;44(6):619-626. Epub 2018 Oct 24.

h Institut für Humanernährung und Lebensmittelkunde, Christian-Albrechts-Universität, Kiel, Germany, 24105.

According to the World Health Organization Expert Consultation, current body mass index (BMI) cut-offs should be retained as an international classification. However, there are ethnic differences in BMI-associated health risks that may be caused by differences in body fat or skeletal muscle mass and these may affect the interpretation of phase angle and bioelectrical impedance vector analysis (BIVA). Therefore, the aim of this study was to compare body composition measured by bioelectrical impedance analysis among 1048 German, 1026 Mexican, and 995 Japanese adults encompassing a wide range of ages and BMIs (18-78 years; BMI, 13.9-44.3 kg/m). Regression analyses between body composition parameters and BMI were used to predict ethnic-specific reference values at the standard BMI cut-offs of 18.5, 25, and 30 kg/m. German men and women had a higher fat-free mass per fat mass compared with Mexicans. Normal-weight Japanese were similar to Mexicans but approached the German phenotype with increasing BMI. The skeletal muscle index (SMI, kg/m) was highest in Germans, whereas in BIVA, the Mexican group had the longest vector, and the Japanese group had the lowest phase angle and the highest extracellular/total body water ratio. Ethnic differences in regional partitioning of fat and muscle mass at the trunk and the extremities contribute to differences in BIVA and phase angle. In conclusion, not only the relationship between BMI and adiposity is ethnic specific; in addition, fat distribution, SMI, and muscle mass distribution vary at the same BMI. These results emphasize the need for ethnic-specific normal values in the diagnosis of obesity and sarcopenia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1139/apnm-2018-0276DOI Listing
June 2019

Determinants of ectopic liver fat in metabolic disease.

Eur J Clin Nutr 2019 02 15;73(2):209-214. Epub 2018 Oct 15.

Institute for Human Nutrition and Food Science, Christian-Albrechts-University Kiel, Kiel, Germany.

Common obesity-associated hepatic steatosis (nonalcoholic fatty liver disease (NAFLD)) and insulin resistance are mainly caused by dysfunctional adipose tissue. This adipose tissue dysfunction leads to increased delivery of NEFA and glycerol to the liver that (i) drives hepatic gluconeogenesis and (ii) facilitates the accumulation of lipids and insulin signaling inhibiting lipid intermediates. Dysfunctional adipose tissue can be caused by impaired lipid storage (overflow hypothesis, characterized by large visceral adipocytes) or increased lipolysis (due to impaired postprandial suppression of lipolysis in inflamed, insulin-resistant adipocytes). In line with the adipose tissue expandability hypothesis the amount and distribution of adipose tissue correlate with its dysfunction and thus with liver fat. This relationship is however modified by endocrine effects on lipid storage and lipolysis as well as dietary effects on hepatic lipogenesis and lipid oxidation. The association between body composition characteristics like visceral obesity or fat cell size and ectopic liver fat is modified by these influences. Phenotyping obesity according to metabolic risk should integrate body composition characteristics, endocrine parameters and information on diet.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41430-018-0323-7DOI Listing
February 2019

Body composition-related functions: a problem-oriented approach to phenotyping.

Eur J Clin Nutr 2019 02 15;73(2):179-186. Epub 2018 Oct 15.

Institute of Human Nutrition and Food Science, Christian-Albrechts-Universität, Kiel, Germany.

Aim: The objective of this study is to generate metabolic phenotypes based on structure-function relationships.

Methods: In 459 healthy adults (54% females, 18 and 40 years old), we analyzed body composition by air-displacement densitometry (to assess fat mass, (FM) and fat-free mass (FFM)) and whole-body magnetic resonance imaging (to assess skeletal muscle mass (SMM) and masses of brain, heart, liver, kidneys, and subcutaneous (SAT) and visceral adipose tissue (VAT)), resting energy expenditure (REE) by indirect calorimetry, and plasma concentrations of insulin (Ins) and leptin (Lep).

Results: Three "functional body composition-derived phenotypes" (FBCPs) were derived: (1) REE on FFM-FBCP, (2) Lep on FM-FBCP, and (3) Ins on VAT-FBCP. Assuming that being within the ± 5% range of the respective regression lines reflects a "normal" structure-function relationship, three "normal" FBCPs were generated with prevalences of 9.0%, 5.1%, and 6.8%, respectively, of the study population. The three "FBCPs" did not overlap and were independent from each other. When compared with the two other FBCPs, the "Lep on FM-FBCP" was leanest, whereas the "REE on FFM-FBCP" had the highest BMI and SAT. Taking into account FFM composition, a hierarchical multi-level model is proposed with brain at level 1, the liver at level 2, and SMM and FM at level 3 with insulin coordinating the interplay between level 1 and 2, whereas variance in plasma insulin levels impacts energy and substrate metabolism in SMM and AT.

Conclusion: Structure-function relationships can be used to generate FBCPs. Different FBCPs reflect different dimensions of normality (or health). This is evidence for the idea that there is no across the board "normal" state.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41430-018-0340-6DOI Listing
February 2019

The anatomy of resting energy expenditure: body composition mechanisms.

Eur J Clin Nutr 2019 02 25;73(2):166-171. Epub 2018 Sep 25.

Department of Human Nutrition and Food Science, Christian-Albrecht's-University of Kiel, Kiel, Germany.

Body mass in humans and animals is strongly associated with the rate of heat production as defined by resting energy expenditure (REE). Beginning with the ancient Greeks up to the present time, philosophers and scientists have endeavored to understand the nature and sources of bodily heat. Today we recognize that body mass consists of organs and tissues, each of which produces a specified amount of heat at rest. An individual organ's REE can now be estimated in vivo as the product of its assumed mass-specific metabolic rate and its imaging-derived mass; whole-body REE reflects the sum of organ and tissue metabolic rates. The sizes of organs and total body mass in adults are governed by two main factors, a person's stature or height, and their level of adiposity. With greater body size, as represented by adult height independent of adiposity, organs remain stable or increase in mass according to distinct "scaling" patterns. Similarly, with greater relative adiposity organs adaptively accommodate to the increase in imposed mechanical and metabolic loading conditions. Through a detailed analysis of these stature and adiposity effects, we show how classical statistical REE prediction models can be mechanistically understood at the anatomic body composition level.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41430-018-0319-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410366PMC
February 2019
-->