Energy balance and obesity

Metabolic Profiles of Obesity in American Indians: The Strong Heart Family Study

Obesity is a typical metabolic disorder resulting from the imbalance between energy intake and expenditure. American Indians suffer disproportionately high rates of obesity and diabetes. The goal of this study is to identify metabolic profiles of obesity in 431 normoglycemic American Indians participating in the Strong Heart Family Study. Using an untargeted liquid chromatography-mass spectrometry, we detected 1,364 distinct m/z features matched to known compounds in the current metabolomics databases. We conducted multivariate analysis to identify metabolic profiles for obesity, adjusting for standard obesity indicators. After adjusting for covariates and multiple testing, five metabolites were associated with body mass index and seven were associated with waist circumference. Of them, three were associated with both. Majority of the obesity-related metabolites belongs to lipids, e.g., fatty amides, sphingolipids, prenol lipids, and steroid derivatives. Other identified metabolites are amino acids or peptides. Of the nine identified metabolites, five metabolites (oleoylethanolamide, mannosyl-diinositol-phosphorylceramide, pristanic acid, glutamate, and kynurenine) have been previously implicated in obesity or its related pathways. Future studies are warranted to replicate these findings in larger populations or other ethnic groups.

Obstructive sleep apnea and energy balance regulation: A systematic review

Obesity and obstructive sleep apnea (OSA) have a reciprocal relationship. Sleep disruptions characteristic of OSA may promote behavioral, metabolic, and/or hormonal changes favoring weight gain and/or difficulty losing weight. The regulation of energy balance (EB), i.e., the relationship between energy intake (EI) and energy expenditure (EE), is complex and multi-factorial, involving food intake, hormonal regulation of hunger/satiety/appetite, and EE via metabolism and physical activity (PA). The current systematic review describes the literature on how OSA affects EB-related parameters. OSA is associated with a hormonal profile characterized by abnormally high leptin and ghrelin levels, which may encourage excess EI. Data on actual measures of food intake are lacking, and not sufficient to make conclusions. Resting metabolic rate appears elevated in OSA vs.

CONTROLS

Findings on PA are inconsistent, but may indicate a negative relationship with OSA severity that is modulated by daytime sleepiness and body weight. A speculative explanation for the positive EB in OSA is that the increased EE via metabolism induces an overcompensation in the drive for hunger/food intake, which is larger in magnitude than the rise in EI required to re-establish EB. Understanding how OSA affects EB-related parameters can help improve weight loss efforts in these patients.

Glucose modulates food-related salience coding of midbrain neurons in humans

Although early rat studies demonstrated that administration of glucose diminishes dopaminergic midbrain activity, evidence in humans has been lacking so far. In the present functional magnetic resonance imaging study, glucose was intravenously infused in healthy human male participants while seeing images depicting low-caloric food (LC), high-caloric food (HC), and non-food (NF) during a food/NF discrimination task. Analysis of brain activation focused on the ventral tegmental area (VTA) as the origin of the mesolimbic system involved in salience coding. Under unmodulated fasting baseline conditions, VTA activation was greater during HC compared with LC food cues. Subsequent to infusion of glucose, this difference in VTA activation as a function of caloric load leveled off and even reversed. In a control group not receiving glucose, VTA activation during HC relative to LC cues remained stable throughout the course of the experiment. Similar treatment-specific patterns of brain activation were observed for the hypothalamus. The present findings show for the first time in humans that glucose infusion modulates salience coding mediated by the VTA. Hum Brain Mapp 37:4376-4384, 2016. © 2016 Wiley Periodicals, Inc.

Browning of White Fat: Novel Insight Into Factors, Mechanisms, and Therapeutics

What is more interesting about brown adipose tissue (BAT) is its ability to provide thermogenesis, protection against obesity by clearing triglycerides, releasing batokines, and mitigating insulin resistance. White adipose tissue (WAT) on the other hand stores excess energy and secretes some endocrine factors like leptin for regulating satiety. For the last decade there has been an increasing interest in the browning of fat keeping in view its beneficial effects on metabolic disorders and protection in the form of perivascular fat. Obesity is one such metabolic disorder that leads to significant morbidity and mortality from obesity-related disorders such as type 2 diabetes mellitus (T2D) and cardiovascular disease risk. Browning of white fat paves the way to restrict obesity and obesity related disorders. Although exercise has been the most common factor for fat browning; however, there are other factors that involve: (1) beta aminoisobutyric acid (BAIBA); (2) gamma amino butyric acid (GABA); (3) PPARɣ agonists; (4) JAK inhibition; and (5) IRISIN. In this review, we propose two novel factors musclin and TFAM for fat browning. Musclin a myokine released from muscles during exercise activates PPARɣ which induces browning of WAT that has beneficial metabolic and cardiac effects. TFAM is a transcription factor that induces mitochondrial biogenesis. Since BAT is rich in mitochondria, higher expression of TFAM in WAT or TFAM treatment in WAT cells can induce browning of WAT. We propose that fat browning can be used as a therapeutic tool for metabolic disorders and cardiovascular diseases. J. Cell. Physiol. 232: 61-68, 2017. © 2016 Wiley Periodicals, Inc.

The role of physical activity and exercise in obesity and weight management: Time for critical appraisal

The prevalence of overweight and obesity has increased dramatically during last 3 decades with devastating consequences to public health. Recommended strategies to reduce obesity have focused on healthier diet and physical activity (PA). Clearly, these approaches have not been successful, but whether this is due to failure to restrict energy intake or to maintain high levels of energy expenditure has been the subject of great controversy. Consequently, there has been a great deal of confusion about the role of PA and exercise in obesity and weight management. In this article, the theoretical basis for considering reduced PA and energy expenditure as the cause of obesity is appraised. Further, the role of PA in food intake and weight control is examined. The idea that obesity is caused by consistent decline in daily energy expenditure is not supported either by objective measures of energy expenditure or physiological theory of weight gain alone. However, since voluntary exercise is the most important discretionary component of total daily energy expenditure, it can affect energy balance. Therefore, PA and exercise hold potential as part of the solution for the ongoing obesity epidemic.

Long-term Effects of Physical Activity Level on Changes in Healthy Body Mass Index Over 12 Years in Young Adult Women

OBJECTIVES

To examine the effects of overall level and timing of physical activity (PA) on changes from a healthy body mass index (BMI) category over 12 years in young adult women.

PATIENTS AND METHODS

Participants in the Australian Longitudinal Study on Women's Health (younger cohort, born 1973-1978) completed surveys between 2000 (age 22-27 years) and 2012 (age 34-39 years). Physical activity was measured in 2000, 2003, 2006, and 2009 and was categorized as very low, low, active, or very active at each survey, and a cumulative PA score for this 9-year period was created. Logistic regression was used to examine relationships between PA accumulated across all surveys (cumulative PA model) and PA at each survey (critical periods PA model), with change in BMI category (from healthy to overweight or healthy to obese) from 2000 to 2012.

RESULTS

In women with a healthy BMI in 2000, there were clear dose-response relationships between accumulated PA and transition to overweight (P=.03) and obesity (P<.01) between 2000 and 2012. The critical periods analysis indicated that very active levels of PA at the 2006 survey (when the women were 28-33 years old) and active or very active PA at the 2009 survey (age 31-36 years) were most protective against transitioning to overweight and obesity.

CONCLUSION

These findings confirm that maintenance of very high PA levels throughout young adulthood will significantly reduce the risk of becoming overweight or obese. There seems to be a critical period for maintaining high levels of activity at the life stage when many women face competing demands of caring for infants and young children.

Ptp1b deletion in pro-opiomelanocortin neurons increases energy expenditure and impairs endothelial function via TNF-α dependent mechanisms

Protein tyrosine phosphatase 1b (Ptp1b) is a negative regulator of leptin and insulin-signalling pathways. Its targeted deletion in proopiomelanocortin (POMC) neurons protects mice from obesity and diabetes by increasing energy expenditure. Inflammation accompanies increased energy expenditure. Therefore, the present study aimed to determine whether POMC-Ptp1b deletion increases energy expenditure via an inflammatory process, which would impair endothelial function. We characterized the metabolic and cardiovascular phenotypes of Ptp1b+/+ and POMC-Ptp1b−/− mice. Clamp studies revealed that POMC-Ptp1b deletion reduced body fat and increased energy expenditure as evidenced by a decrease in feed efficiency and an increase in oxygen consumption and respiratory exchange ratio. POMC-Ptp1b deletion induced a 2.5-fold increase in plasma tumour necrosis factor α (TNF-α) levels and elevated body temperature. Vascular studies revealed an endothelial dysfunction in POMC-Ptp1b−/− mice. Nitric oxide synthase inhibition [N-nitro-L-arginine methyl ester (L-NAME)] reduced relaxation to a similar extent in Ptp1b+/+ and POMC-Ptp1b−/− mice. POMC-Ptp1b deletion decreased ROS-scavenging enzymes [superoxide dismutases (SODs)] whereas it increased ROS-generating enzymes [NADPH oxidases (NOXs)] and cyclooxygenase-2 (COX-1) expression, in aorta. ROS scavenging or NADPH oxidase inhibition only partially improved relaxation whereas COX-2 inhibition and thromboxane-A2 (TXA2) antagonism fully restored relaxation in POMC-Ptp1b−/− mice. Chronic treatment with the soluble TNF-α receptor etanercept decreased body temperature, restored endothelial function and reestablished aortic COX-2, NOXs and SOD expression to their baseline levels in POMC-Ptp1b−/− mice. However, etanercept promoted body weight gain and decreased energy expenditure in POMC-Ptp1b−/− mice. POMC-Ptp1b deletion increases plasma TNF-α levels, which contribute to body weight regulation via increased energy expenditure and impair endothelial function via COX-2 and ROS-dependent mechanisms.

Is Obesity Associated with Altered Energy Expenditure?

Historically, obese individuals were believed to have lower energy expenditure (EE) rates than nonobese individuals (normal and overweight), which, in the long term, would contribute to a positive energy balance and subsequent weight gain. The aim of this review was to critically appraise studies that compared measures of EE and its components, resting EE (REE), activity EE (AEE), and diet-induced thermogenesis (DIT), in obese and nonobese adults to elucidate whether obesity is associated with altered EE. Contrary to popular belief, research has shown that obese individuals have higher absolute REE and total EE. When body composition (namely the metabolically active component, fat-free mass) is taken into account, these differences between obese and nonobese individuals disappear, suggesting that EE in obese individuals is not altered. However, an important question is whether AEE is lower in obese individuals because of a decrease in overall physical activity or because of less energy expended while performing physical activity. AEE and DIT could be reduced in obese individuals, mostly because of unhealthy behavior (low physical activity, higher intake of fat). However, the current evidence does not support the hypothesis that obesity is sustained by lower daily EE or REE. Future studies, comparing EE between obese and nonobese and assessing potential physiologic abnormalities in obese individuals, should be able to better answer the question of whether these individuals have altered energy metabolism.

Comparing Prices for Food and Diet Research: The Metric Matters

An important issue in research into access to healthy food is how best to compare the price of foods. The appropriate metric for comparison has been debated at length, with proponents variously stating that food prices should be compared in terms of their energy content, their edible mass, or their typical portion size. In this article we assessed the impact of using different food price metrics on the observed difference in price between food groups and categories of healthiness, using United Kingdom consumer price index data for 148 foods and beverages in 2012. We found that the choice of metric had a marked effect on the findings and conclude that this must be decided in advance to suit the reason for comparing food prices.

Recruitment, screening, and baseline participant characteristics in the WALK 2.0 study: A randomized controlled trial using web 2.0 applications to promote physical activity

OBJECTIVE

To describe in detail the recruitment methods and enrollment rates, the screening methods, and the baseline characteristics of a sample of adults participating in the Walk 2.0 Study, an 18 month, 3-arm randomized controlled trial of a Web 2.0 based physical activity intervention.

METHODS

A two-fold recruitment plan was developed and implemented, including a direct mail-out to an extract from the Australian Electoral Commission electoral roll, and other supplementary methods including email and telephone. Physical activity screening involved two steps: a validated single-item self-report instrument and the follow-up Active Australia Questionnaire. Readiness for physical activity participation was also based on a two-step process of administering the Physical Activity Readiness Questionnaire and, where needed, further clearance from a medical practitioner.

RESULTS

Across all recruitment methods, a total of 1244 participants expressed interest in participating, of which 656 were deemed eligible. Of these, 504 were later enrolled in the Walk 2.0 trial (77% enrollment rate) and randomized to the Walk 1.0 group (n = 165), the Walk 2.0 group (n = 168), or the Logbook group (n = 171). Mean age of the total sample was 50.8 years, with 65.2% female and 79.1% born in Australia.

CONCLUSION

The results of this recruitment process demonstrate the successful use of multiple strategies to obtain a diverse sample of adults eligible to take part in a web-based physical activity promotion intervention. The use of dual screening processes ensured safe participation in the intervention. This approach to recruitment and physical activity screening can be used as a model for further trials in this area.

The Obesities: Various Paradigms Addressing a Single Problem

This article provides a commentary on the article titled "The Obesities: An Overview of Convergent and Divergent Paradigms" by Karasu. Addressing the concept of obesity from various viewpoints, the article reflects the multicausal nature of a problem many societies are facing. Despite the ongoing controversy on who is to blame for the obesity epidemic, the underlying concept of obesity remains an imbalance between energy intake and energy expenditure. These 2 components, therefore, need to be considered in synchrony rather than being separated. Similarly, the complex interaction between individual, environmental, and physiological constraints warrants a multidisciplinary approach to enhance the understanding of the regulation of energy balance rather than a separation into several different areas of "obesities."

Influence of polymorphisms of the beta-2 adrenergic receptor on the presence of exercise-induced bronchospasm in adolescents

Objective:

To determine the influence of polymorphisms of the beta-2 adrenergic receptor (ADRB2) in triggering exercise-induced bronchospasm (EIB) in adolescents.

Methods:

The subjects were divided into two groups: present EIB (EIB+) (n=45) and absent EIB (EIB−) (n=115). The bronchial provocation test with exercise was performed with a protocol that consisted of walking/running for at least eight minutes at high intensity, i.e., >85% of maximum heart rate, considering EIB+ as a 10% decrease in forced expiratory volume in one second (FEV₁). The genotyping of the ADRB2 gene was performed by the Taqman method, using the Step One Plus system. Independent t-test, Mann–Whitney and Chi-square tests, as well as Spearman's correlation coefficient were used for the statistical analysis.

Results:

Age, body weight, height, FEV₁, FVC and FEV₁/FVC ratio were lower in the EIB+ group when compared to EIB− (p<0.05). There were no significant differences in the proportion of the allele at position 27 and Arg16Gly and Gln27Glu genotypes between the EIB+ and EIB− groups (p=0.26; p=0.97 and p=0.43, respectively). However, there was a trend toward statistical significance regarding the greater proportion of the Gly16 allele for the EIB+ when compared to the EIB− group (p=0.08).

Conclusions:

The presence of polymorphisms associated with the Glu27 allele and Arg16Gly and Gln27Glu genotypes had no influence on EIB. However, the statistical trend toward greater frequency of the Gly16 allele in individuals with EIB+ can be considered evidence of the influence of polymorphisms of the ADBR2 gene on EIB in adolescents.

Are physical activity, sedentary behaviors and sleep duration associated with body mass index-for-age and health-related quality of life among high school boys and girls?

BACKGROUND

Previous studies reported lower health-related quality of life (HRQOL) scores in overweight and obese adolescents compared to their normal weight counterparts; however, few studies investigated the association between obesity-related behaviors including physical activity and sedentary behaviors and HRQOL in adolescents. This study aimed at investigating the relationship between physical activity, sedentary behaviors, sleep duration and body mass index-for-age (BMI-for-age) and HRQOL among high school Tehranian students.

METHODS

A total of 465 high school students (48.8 % girls) were recruited from three different socio-economic zones in Tehran. The BMI-for-age was determined and physical activity and HRQOL were assessed using validated questionnaires including Quantification de l'Activite Physique en Altitude Chez les Enfants (QAPACE) and Pediatric Quality of Life Inventory (PedsQL) respectively.

RESULTS

Over one third of students (38.5 %) were either overweight or obese. The means of all self- and parent-reported HRQOL scores were significantly lower in girls, compared to boys, except for the parent-reported social functioning subscale. Mean hours of daily sleeping were significantly higher in girls, compared to boys (8.16 ± 1.27 vs. 7.73 ± 1.22 respectively; p < 0.05). Both girls and boys spent more time on sedentary activities than engaging in sport activities. During school and vacation periods, boys had significantly higher daily energy expenditure (DEE) compared to girls (p < 0.05). Only DEE during school period had a significant inverse correlation with BMI-for-age in boys but not girls (r = -0.14, p < 0.05). In addition, self-reported HRQOL scores were significantly associated with weekly hours adolescents spent on videogames/internet, listening to music and reading, watching TV, sports as well as DEE through sex-specific patterns. However according to parents' perspective only weekly hours spent on listening to music and readings and sport activities were significantly associated with their children HRQOL scores.

CONCLUSION

In summary, time spent on physical and sedentary activities were not associated with BMI-for-age, although both of these were associated with the HRQOL of high school students. The potential role of sedentary activities and physical activity should be considered in future interventions aimed at improving HRQOL in adolescents.

Histone Deacetylase 1 (HDAC1) Negatively Regulates Thermogenic Program in Brown Adipocytes via Coordinated Regulation of Histone H3 Lysine 27 (H3K27) Deacetylation and Methylation

Inhibiting class I histone deacetylases (HDACs) increases energy expenditure, reduces adiposity, and improves insulin sensitivity in obese mice. However, the precise mechanism is poorly understood. Here, we demonstrate that HDAC1 is a negative regulator of the brown adipocyte thermogenic program. The Hdac1 level is lower in mouse brown fat (BAT) than white fat, is suppressed in mouse BAT during cold exposure or β3-adrenergic stimulation, and is down-regulated during brown adipocyte differentiation. Remarkably, overexpressing Hdac1 profoundly blocks, whereas deleting Hdac1 significantly enhances, β-adrenergic activation-induced BAT-specific gene expression in brown adipocytes. β-Adrenergic activation in brown adipocytes results in a dissociation of HDAC1 from promoters of BAT-specific genes, including uncoupling protein 1 (Ucp1) and peroxisome proliferator-activated receptor γ co-activator 1α (Pgc1α), leading to increased acetylation of histone H3 lysine 27 (H3K27), an epigenetic mark of gene activation. This is followed by dissociation of the polycomb repressive complexes, including the H3K27 methyltransferase enhancer of zeste homologue (EZH2), suppressor of zeste 12 (SUZ12), and ring finger protein 2 (RNF2) from (and concomitant recruitment of H3K27 demethylase ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX) to) Ucp1 and Pgc1α promoters, leading to decreased H3K27 trimethylation, a histone transcriptional repression mark. Thus, HDAC1 negatively regulates the brown adipocyte thermogenic program, and inhibiting Hdac1 promotes BAT-specific gene expression through a coordinated control of increased acetylation and decreased methylation of H3K27, thereby switching the transcriptional repressive state to the active state at the promoters of Ucp1 and Pgc1α. Targeting HDAC1 may be beneficial in prevention and treatment of obesity by enhancing BAT thermogenesis.

Increasing energy flux to decrease the biological drive toward weight regain after weight loss - A proof-of-concept pilot study

OBJECTIVE

Weight loss induces compensatory biological adjustments that increase hunger and decrease resting metabolic rate (RMR), which increase propensity for weight regain. In non-obese adults high levels of physical activity coupled with high energy intake (high energy flux) are associated with higher RMR and reduced hunger. We tested the possibility that a high flux state attenuates the increase in hunger and the decrease in RMR characteristic of diet-induced weight loss.

METHODS

Six obese adults [age (mean ± SE) = 42 ± 12 y; body mass index (BMI) = 35.7 ± 3.7 kg/m²] underwent measures of RMR, the thermic effect of a meal (TEM), and fasting and postprandial measures of hunger and fullness as well as plasma glucose and insulin. Following weight loss, subjects completed two 5-day conditions of energy balance in random order-Low Flux (LF): sedentary with energy intake (EI) = RMR (kcal/d) × 1.35; and High Flux (HF): net exercise energy cost of ∼500 kcal/d and EI = RMR (kcal/d) × 1.7. RMR was measured daily for each flux condition. The morning following each of the respective experimentally controlled HF and LF conditions (flux day 5), they underwent the same pre-weight loss tests and also reported their perceptions of hunger and fullness during the previous four days of HF and LF, respectively.

RESULTS

Average daily RMR was higher during HF (1926 ± 138 kcal/day) compared to LF (1847 ± 126 kcal/day; P < 0.05). Perceived hunger at the end of day was lower (p < 0.03) and fullness throughout the day was higher (p < 0.02) in HF compared to LF conditions. On day 5 of each flux condition, the thermic effect of a meal and circulating glucose and insulin after the meal did not differ between HF and LF.

CONCLUSION

Following weight loss, compared to a sedentary LF state of energy balance, a short-term HF energy balance state is associated with higher RMR, lower perceived hunger, and greater perceived fullness, all of which could help attenuate the biologic drive to regain weight. Given the pilot nature of this study and the relatively short period of time spent in the high and low flux states, future research is needed to address this research question in a larger sample over a longer time period.

Web-Based and Mobile Delivery of an Episodic Future Thinking Intervention for Overweight and Obese Families: A Feasibility Study

Background

The bias toward immediate gratification is associated with maladaptive eating behaviors and has been cross-sectionally and prospectively related to obesity. Engaging in episodic future thinking, which involves mental self-projection to pre-experience future events, reduces this bias and energy intake in overweight/obese adults and children. To examine how episodic future thinking can be incorporated into clinical interventions, a Web-based system was created to provide training for adults and children in their everyday lives.

Objective

Our study examined the technical feasibility, usability, and acceptability of a Web-based system that is accessible by mobile devices and adapts episodic future thinking for delivery in family-based obesity interventions.

Methods

We recruited 20 parent-child dyads (N=40) from the surrounding community and randomized to episodic future thinking versus a nutritional information thinking control to test the feasibility of a 4-week Web-based intervention. Parents were 44.1 (SD 7.8) years of age with BMI of 34.2 (SD 6.8) kg/m². Children were 11.0 (SD 1.3) years of age with BMI percentile of 96.0 (SD 1.8). Families met weekly with a case manager for 4 weeks and used the system daily. Adherence was collected through the Web-based system, and perceived acceptance of the Web-based system was assessed postintervention. Measurements of body composition and dietary intake were collected at baseline and after the 4 weeks of intervention.

Results

All 20 families completed the intervention and attended all sessions. Results showed parents and children had high adherence to the Web-based system and perceived it to be easy to use, useful, and helpful. No differences between conditions were found in adherence for parents (P=.65) or children (P=.27). In addition, results suggest that basic nutrition information along with episodic future thinking delivered through our Web-based system may reduce energy intake and weight.

Conclusions

We showed that our Web-based system is an accepted technology and a feasible utility. Furthermore, results provide initial evidence that our system can be incorporated into family-based treatments targeting behaviors related to weight control. These results show promising utility in using our Web-based system in interventions.

A talk between fat tissue, gut, pancreas and brain to control body weight

The incidence of obesity and its related disorders are increasing at a rate of pandemic proportions. Understanding the mechanisms behind the maintenance of energy balance is fundamental in developing treatments for clinical syndromes including obesity and diabetes. A neural network located in the nucleus of the solitary tract-area postrema complex in the hindbrain and the hypothalamus in the forebrain has long been implicated in the control of energy balance. In the hypothalamus this central neuronal network consists of small populations of nuclei with distinct functions such as the arcuate nucleus (ARH), the paraventricular nuclei of the hypothalamus (PVH), the dorsomedial (DMH), the ventromedial (VMH) and the lateral hypothalamus (LH). These hypothalamic areas form interconnected neuronal circuits that respond to fluctuations in energy status by altering the expression of neuropeptides, leading to changes in energy intake and expenditure. Regulation of these hypothalamic nuclei involves the actions of orexigenic peptides (ie ghrelin), which act to stimulate energy intake and decrease energy expenditure, and anorexigenic peptides (ie. leptin and insulin), which act to reduce energy intake and stimulate energy expenditure. Here we review the role of the ARH, DMH and PVH in the control of energy homeostasis and how recent advances in research technologies (Cre-loxP technology, optogenetics and pharmacogenetics) have shed light on the role of these hypothalamic nuclei in the control of energy balance. Such novel findings include the implication of ARH POMC and AgRP neurons in the browning of white adipose tissue to regulate energy expenditure as well as the likely existence of divergent hypothalamic pathways in the DMH and PVH in the control of food intake and energy expenditure.

Inability to match energy intake with energy expenditure at sustained near-maximal rates of energy expenditure in older men during a 14-d cycling expedition

BACKGROUND

The upper rates of energy expenditure (EE) and the corresponding regulation of energy intake (EI), as described in younger trained subjects, are not well elucidated in older subjects.

OBJECTIVES

The aim was to investigate EE in older men during prolonged cycling and determine whether it is sufficiently matched by EI to maintain energy balance. In addition, we investigated appetite ratings and concentrations of appetite-regulating hormones.

DESIGN

Six men (mean ± SE age: 61 ± 3 y) completed 2706 km of cycling, from Copenhagen to Nordkapp, in 14 d. EE was measured by using doubly labeled water, and food and drink intake was recorded by the accompanying scientific staff. Energy balance was calculated as the discrepancy between EI and EE and from changes in body energy stores as derived from deuterium dilution. Fasting hormones were measured before and after cycling, and appetite ratings were recorded twice daily.

RESULTS

EE (±SE) increased from 17 ± 1 MJ/d before to 30 ± 2 MJ/d during the cycling trip (P < 0.001), which is equivalent to 4.0 ± 0.1 times the basal metabolic rate. Although body weight remained stable during the 14 d of cycling, body fat decreased (-2.2 ± 0.7 kg; P = 0.02) and fat-free mass increased (2.5 ± 0.6 kg; P = 0.01). EI was 25 ± 1 MJ/d during cycling, resulting in a negative energy balance calculated by the EE - EI gap (-5.2 ± 1.2 MJ/d). Calculated from changes in body energy stores, energy balance was also negative (-4.8 ± 2.0 MJ/d) during the first week. In the morning and evening, hunger ratings increased (both P = 0.02), whereas ratings of fullness decreased in the evening (P = 0.04). Fasting plasma concentrations of insulin increased by 120% ± 15% (P = 0.02), glucagon-like peptide 1 (GLP-1) by 60% ± 20% (P < 0.01), and Polypeptide YY(3-36) by 80% ± 30% (P < 0.02) after cycling.

CONCLUSIONS

Older male cyclists sustained near-maximal rates of EE during prolonged cycling but were unable to upregulate EI to maintain energy balance. Despite the presence of increased motivation to eat, a more profound counteracting physiologic stimulus inhibiting increases in EI was present. This trial was registered at clinicaltrials.gov as NCT02353624.

Placement of a take-out container during meal influences energy intake

A growing body of research suggests that increased portion sizes are contributing to the rising rates of obesity. However, studies that focus on environmental cues to promote portion control are relatively limited. Thus, a randomized study was conducted in a controlled laboratory setting to determine if the presence of a take-out container, given at the start of a meal, would prompt experimental group participants to decrease the portion of food consumed and reduce energy intake. Outcomes were analyzed using descriptive statistics, independent t-tests, and analysis of covariance. Results showed that placing a take-out container with the test meal led to a significant difference in energy intake (p=0.000) when compared to the control group. Participants (n=25) who were given a take-out container with their test meal consumed an average of 90 kcal less than participants (n=25) who were not given the condition. These findings suggest that a to-go container may be utilized as an effective environmental cue for guiding consumers to control serving size when faced with over-sized portions at restaurants or other food outlets.

Health burden and costs of obesity and overweight in Germany: an update

In 2011, Konnopka et al. (Eur J Health Econ 12:345-352, 2011) published a top-down cost of illness study on the health burden, and direct and indirect costs of morbidity and mortality attributable to excess weight (BMI ≥25 kg/m(2)) in Germany in 2002. The objective of the current study was to update the 2002 estimates to the year 2008. To simplify comparisons, we closely followed the methods and assumptions of the original study, using 2008 data for most input parameters (e.g. prevalence, mortality, resource use, costs). Excess weight related deaths increased by 31% (from 36,653 to 47,964) and associated years of potential life lost (from 428,093 to 588,237) and quality adjusted life years lost (from 367,722 to 505,748) by about 37%, respectively. Excess weight caused €16,797 million in total costs in 2008 (+70%), of which €8,647 million were direct costs (corresponding to 3.27% of total German health care expenditures in 2008). About 73% (€12,235 million) of total excess weight related costs were attributable to obesity (BMI ≥30 kg/m(2)). The main drivers of direct costs were endocrinological (44%) and cardiovascular (38%) diseases. Indirect costs amounted to €8,150 million in 2008 (+62%), of which about two-thirds were indirect costs from unpaid work. The great majority of indirect costs were due to premature mortality (€5,669 million). The variation of input parameters (univariate sensitivity analyses) resulted in attributable costs between €8,978 million (-47% compared to base case) and €25,060 million (+49%). The marked increase in excess weight related costs can largely be explained by increases in the prevalence of overweight and obesity, and to a lesser extent from increases in resource consumption, as well as increases in (unit) costs and wages (comprising 5.5% inflation).

Energy flux: staying in energy balance at a high level is necessary to prevent weight gain for most people

Energy flux, the rate of energy conversion from absorption to expenditure or storage, is a critical component of understanding weight management. Individuals who maintain body weight over time have common characteristics including a relatively high level of physical activity and minimal changes in body composition, muscle mass and metabolic rate. A higher state of energy flux resulting from high energy expenditure may provide for a greater 'sensitivity' between energy intake and expenditure. This sensitivity stabilizes body weight by enhancing reciprocal compensation among these components with changes in eating or activity. The energy balance framework suggests that a higher level of energy expenditure requires higher energy intake to maintain body mass. Maintaining energy balance at a higher caloric intake and expenditure should be a more successful long-term strategy for weight maintenance than reduced consumption or extreme caloric restriction at a low level of energy expenditure (a low energy flux) and improve intervention effectiveness for sustainable methods for body weight stability.

Childhood obesity: a (re) programming disease?

The aim of our article was to review the current literature on the effects of metabolic (re) programming on childhood obesity. PubMed/MEDLINE was the data source used to track the studies. Descriptors applied: children obesity, epigenetic, metabolic programming, exercise and nutrition. The focus was to analyze and discuss the international findings on the theme. The gathering of the papers was performed between June and August 2014. The search of articles with the descriptors used found 33.054 studies. In all, 5.709 studies were selected by crossing chosen keywords. Among these, after careful reading of the titles, 712 papers were considered potential as references. After applying inclusion/exclusion criteria, 50 studies were selected from 132 eligible abstracts. Most studies linked the development and treatment of obesity from epigenetically stimulated metabolic programming during the early stages of pregnancy and life. This review provides theoretical basis to the understanding that the programmed development of childhood obesity may be linked to early exposure to environmental factors, such as (nutrition and regular practice of exercise) and stimulus can epigenetically alter the modulation of the obesogenic metabolic behavior during pregnancy and the developmental stages of children and/or postpone the pathophysiologic disease stage to adulthood.

Effects of black adzuki bean (Vigna angularis, Geomguseul) extract on body composition and hypothalamic neuropeptide expression in rats fed a high-fat diet

Background

Obesity is often considered to result from either excessive food intake or insufficient physical activity. Adzuki beans have been evaluated as potential remedies for various health conditions, and recent studies have reported their effects on the regulation of lipid metabolism, but it remains to be determined whether they may be effective in overcoming obesity by regulating appetite and satiety.

Objective

This study investigated the effect of black adzuki bean (BAB) extract on body composition and hypothalamic neuropeptide expression in Sprague Dawley rats (Rattus norvegicus) fed a high-fat diet.

Design

The rats were fed for 8 weeks with a control diet containing 10 kcal% from fat (CD), a high-fat diet containing 60 kcal% from fat (HD), or a high-fat diet with 1% or 2% freeze-dried ethanolic extract powder of BAB (BAB-1 and BAB-2).

Results

The body weights and epididymal fat weights were significantly reduced and the serum lipid profiles were improved in the group fed the diet containing BAB compared to the HD group. The expression of AGRP mRNA significantly decreased in the BAB groups, and treatment with BAB-2 resulted in a marked induction of the mRNA expression of POMC and CART, which are anorexigenic neuropeptides that suppress food intake. Furthermore, mRNA expression levels of ObRb, a gene related to leptin sensitivity in the hypothalamus, were significantly higher in the BAB groups than in the HD group.

Conclusions

These results suggest that supplementation with BAB has a significant effect on body weight via regulation of hypothalamic neuropeptides.

[Influence of polymorphisms of the beta-2 adrenergic receptor on the presence of exercise-induced bronchospasm in adolescents]

OBJECTIVE

To determine the influence of polymorphisms of the beta-2 adrenergic receptor (ADRB2) in triggering exercise-induced bronchospasm (EIB) in adolescents.

METHODS

The subjects were divided into two groups: present EIB (EIB+) (n=45) and absent EIB (EIB-) (n=115). The bronchial provocation test with exercise was performed with a protocol that consisted of walking/running for at least eight minutes at high intensity, i.e., >85% of maximum heart rate, considering EIB+ as a 10% decrease in forced expiratory volume in one second (FEV1). The genotyping of the ADRB2 gene was performed by the Taqman method, using the Step One Plus system. Independent t-test, Mann-Whitney and Chi-square tests, as well as Spearman's correlation coefficient were used for the statistical analysis.

RESULTS

Age, body weight, height, FEV1, FVC and FEV1/FVC ratio were lower in the EIB+ group when compared to EIB- (p<0.05). There were no significant differences in the proportion of the allele at position 27 and Arg16Gly and Gln27Glu genotypes between the EIB+ and EIB- groups (p=0.26; p=0.97 and p=0.43, respectively). However, there was a trend towards statistical significance regarding the greater proportion of the Gly16 allele for the EIB+ when compared to the EIB- group (p=0.08).

CONCLUSIONS

The presence of polymorphisms associated with the Glu27 allele and Arg16Gly and Gln27Glu genotypes had no influence on EIB. However, the statistical trend towards greater frequency of the Gly16 allele in individuals with EIB+ can be considered evidence of the influence of polymorphisms of the ADBR2 gene on EIB in adolescents.

Macro fat and micro fat: insulin sensitivity and gender dependent response of adipose tissue to isocaloric diet change

The adipose cell-size distribution is a quantitative characterization of adipose tissue morphology. At a population level, the adipose cell-size distribution is insulin-sensitivity dependent, and the observed correlation between obesity and insulin resistance is believed to play a key role in the metabolic syndrome. Changes in fat mass can be induced by altered energy intake or even diet composition. These macroscopic changes must manifest themselves as dynamic adipose cell-size distribution alterations at the microscopic level. The dynamic relationship between these 2 independent measurements of body fat is unknown. In this study, we investigate adipose tissue dynamics in response to various isocaloric diet compositions, comparing gender- and insulin sensitivity-dependent differences. A body composition model is used to predict fat mass changes in response to changes in diet composition for 28 individuals, separated into 4 subgroups according to gender and insulin sensitivity/resistance. Adipose cell-size distribution changes in each individual are simulated with a dynamic model and parameters corresponding to lipid turnover and cell growth rates are determined for each subgroup to match the relative change of fat mass for each diet composition, respectively. We find that adipose cell-size dynamics are associated with different modulations dependent on gender and insulin resistance. Larger turnover and growth/shrinkage rates in insulin resistant individuals suggest they may be more sensitive to changes in energy intake and diet composition than insulin sensitive subjects. The different cell-size distribution changes of adipose cells of various sizes in different subject groups further suggest distinct modulations of adipose cell dynamics.

Can prokineticin prevent obesity and insulin resistance?

PURPOSE OF REVIEW

Because of its increasing prevalence and morbi-mortality, obesity is a major health problem. Obesity etiology includes a combination of excess dietary calories and decreased physical activity, coupled with either predisposing genetic factors or metabolic disorders such as insulin resistance. Adipose tissue secretes several metabolically important proteins known as 'adipokines' that play a major role in obesity and insulin resistance. High levels of a newly identified group of adipokines, called prokineticins, have been found in obese adipose tissues. Prokineticins are peptide hormones released principally from macrophages and reproductive organs. They act on the G protein-coupled receptors PKR1 and PKR2. This review aims to provide an overview of current knowledge of the role of prokineticins and their receptors in the development of obesity and insulin resistance.

RECENT FINDINGS

The principal biological effect of prokineticins in the central nervous system is the control of food intake. Nevertheless, peripheral biological effects of prokineticin are associated with increasing insulin sensitivity and suppressing the adipose tissue expansion.

SUMMARY

We outline the biological significance of the central and peripheral effects of prokineticins, and the potential of their receptors as targets for the treatment of obesity and insulin resistance.

Reciprocal Compensation to Changes in Dietary Intake and Energy Expenditure within the Concept of Energy Balance

An imbalance between energy intake and energy expenditure is the primary etiology for excess weight gain. Increased energy expenditure via exercise and energy restriction via diet are commonly used approaches to induce weight loss. Such behavioral interventions, however, have generally resulted in a smaller than expected weight loss, which in part has been attributed to compensatory adaptations in other components contributing to energy balance. Current research points to a loose coupling between energy intake and energy expenditure on a daily basis, and evidence for long-term adaptations has been inconsistent. The lack of conclusive evidence on compensatory adaptations in response to alterations in energy balance can be attributed to differences in intervention type and study population. Physical activity (PA) levels may be reduced in response to aerobic exercise but not in response to resistance exercise. Furthermore, athletic and lean adults have been shown to increase their energy intake in response to exercise, whereas no such response was observed in obese adults. There is also evidence that caloric restriction is associated with a decline in PA. Generally, humans seem to be better equipped to defend against weight loss than avoid weight gain, but results also show a large individual variability. Therefore, individual differences rather than group means should be explored to identify specific characteristics of "compensators" and "noncompensators." This review emphasizes the need for more research with simultaneous measurements of all major components contributing to energy balance to enhance the understanding of the regulation of energy balance, which is crucial to address the current obesity epidemic.

An economy of scales: A selective review of obesity's economic causes, consequences, and solutions

This paper reviews the economic research on obesity, covering topics such as the measurement of, and trends in, obesity, the economic causes of obesity (e.g. the monetary price and time cost of food, food assistance programs, income, education, macroeconomic conditions, and peer effects), and the economic consequences of obesity (e.g. lower wages, a lower probability of employment, and higher medical care costs). It also examines the extent to which obesity imposes negative externalities, and economic interventions that could potentially internalize such externalities, such as food taxes, subsidies for school-based physical activity programs, and financial rewards for weight loss. It discusses other economic rationales for government intervention with respect to obesity, such as imperfect information, time inconsistent preferences, and irrational behavior. It concludes by proposing a research agenda for the field. Overall, the evidence suggests that there is no single dominant economic cause of obesity; a wide variety of factors may contribute a modest amount to the risk. There is consistent evidence regarding the economic consequences of obesity, which are lower wages and higher medical care costs that impose negative externalities through health insurance. Studies of economic approaches to preventing obesity, such as menu labeling, taxes on energy-dense foods, and financial rewards for weight loss find only modest effects on weight and thus a range of policies may be necessary to have a substantial effect on the prevalence of obesity.

Cross-sectional and prospective associations between moderate to vigorous physical activity and sedentary time with adiposity in children

BACKGROUND

Physical activity (PA) and sedentary time (SED) have both been suggested as potential risk factors for adiposity in children. However, there is paucity of data examining the temporal associations between these variables.

OBJECTIVE

This study aimed to analyze the cross-sectional and prospective associations between PA, SED and body composition in children.

METHODS

A total of 510 children (age at baseline 10.1±0.8, age at follow-up 11.8±0.9) from six Portuguese schools from the Oeiras Municipality participated in this study. PA and SED were measured by accelerometry and trunk fat mass (TFM) and body fat mass (BFM) were measured by dual energy X-ray absorptiometry. Fat mass index (FMI) was calculated as BFM divided by height squared. Several regression models adjusted for age, sex, maturity status, follow-up duration, baseline levels of the outcome variable and SED or moderate to vigorous PA (MVPA) were performed.

RESULTS

MVPA (min per day) was cross-sectionally inversely associated with adiposity indexes (FMI, TFM and BFM). Adiposity indexes were inversely associated with time in MVPA. In prospective analyses, MVPA was associated with a lower levels of FMI (β=-0.37, 95% confidence interval (CI): -0.49 to -0.26, P<0.001), TFM (β=-0.20, 95% CI: -0.29 to -0.10, P<0.001) and BFM (β=-0.37, 95% CI: -0.49 to -0.26, P<0.001). When the model was adjusted for age, sex, maturity status and for baseline levels of the outcome variables MVPA remained a significant predictor of lower adiposity indexes (FMI: β=-0.09, 95% CI: -0.16 to -0.01, P<0.05; TFM: β=-0.08, 95% CI: -0.15 to -0.01, P<0.05; BFM: β=-0.07, 95% CI: -0.15 to 0.00, P<0.05). Adiposity was not associated with MVPA when modeled as the exposure in prospective analyses. SED was not related with adiposity indexes, except for the relationship with FMI.

CONCLUSIONS

In cross-sectional and prospective analyses, MVPA is associated with lower adiposity independent of covariates and SED. Results suggest that promoting MVPA is important for preventing gain in adiposity in healthy children.

The Histone Demethylase UTX Promotes Brown Adipocyte Thermogenic Program Via Coordinated Regulation of H3K27 Demethylation and Acetylation

Brown adipocytes function to dissipate energy as heat through adaptive thermogenesis. Understanding the molecular mechanisms underlying the brown fat thermogenic program may provide insights for the development of therapeutic approaches in the treatment of obesity. Most studies investigating the mechanisms underlying brown fat development focus on genetic mechanisms; little is known about the epigenetic mechanisms in this process. We have discovered that ubiquitously transcribed tetratricopeptide repeat on chromosome X (UTX), a histone demethylase for di- or tri-methylated histone 3 lysine 27 (H3K27me2/3), plays a potential role in regulating brown adipocyte thermogenic program. We found that UTX is up-regulated during brown adipocyte differentiation and by cold exposure in both brown adipose tissue (BAT) and white adipose tissue (WAT) of mice, suggesting a potential role in thermogenesis. Inactivation of UTX down-regulates brown fat specific gene expression, while overexpression of UTX does the opposite. Notably, activation of β adrenergic signaling recruits UTX to the UCP1 and PGC1α promoters, leading to decreased H3K27me3, a histone transcriptional repressive mark. UTX demethylates H3K27me3 and subsequently interacts with the histone acetyltransferase (HAT) protein CBP, resulting in increased H3K27 acetylation (H3K27ac), a histone transcriptional active mark. UTX positively regulate brown adipocyte thermogenic program through coordinated control of demethylating H3K27me3 and acetylating H3K27, switching the transcriptional repressive state to the transcriptional active state at the promoters of UCP1 and PGC1α. We conclude that UTX may play a potential role in regulation of brown adipocyte gene expression and may mediate β adrenergic activation of brown fat function.

Regulation of brown fat by AMP-activated protein kinase

Novel strategies are needed to reduce the obesity epidemic. One promising strategy is activation of brown adipose tissue (BAT), either via the brain or directly, which increases energy expenditure by combustion of fatty acids (FAs) into heat. The enzyme complex AMP-activated protein kinase (AMPK) is crucially involved in energy metabolism and is highly expressed in both brain and BAT, regulating thermogenesis. As a general rule, BAT activity and energy expenditure are increased either by suppression of AMPK activity in the brain, resulting in enhanced sympathetic outflow towards BAT, or by activation of AMPK in BAT. Targeting AMPK may thus hold therapeutic potential for the treatment of obesity and related disorders.

Serum N(1)-Methylnicotinamide Is Associated With Obesity and Diabetes in Chinese

CONTEXT

Nicotinamide N-methyltransferase (NNMT) is a novel histone methylation modulator that regulates energy metabolism, and NNMT knockdown prevents diet-induced obesity in mice. However, whether NNMT plays a role in human obesity and type 2 diabetes (T2DM) remains to be elucidated.

OBJECTIVE

NNMT catalyzes methylation of nicotinamide to generate N(1)-methylnicotinamide (me-NAM). We aimed to investigate the associations of serum me-NAM with obesity and T2DM in Chinese.

DESIGN, SETTING, AND PARTICIPANTS

The study subjects (n = 1160) were recruited from Dali, a city of Yunnan Province, in southwest China. Anthropometric phenotypes, fasting glucose, and serum lipids were measured. Serum me-NAM was measured by liquid chromatography-mass spectrometry.

RESULTS

Serum me-NAM was positively correlated with body mass index and waist circumference and negatively with high-density lipoprotein (P ≤ .03). The correlations remained highly significant in the multivariate adjusted correlation analyses. In men (n = 691), positive correlations between me-NAM and fasting glucose, low-density lipoprotein, liver function, and serum creatinine levels were also observed in both simple and multivariate adjusted correlation analyses. In multiple logistic regression analyses, elevated serum me-NAM was associated with higher risks for overweight/obesity (odds ratios, 2.36 and 5.78; 95% confidence intervals, 1.10-5.08 and 1.78-18.76 for men and women, respectively; P ≤ .03) and diabetes (odds ratios, 1.56 and 1.86; 95% confidence intervals, 1.10-2.22 and 1.05-3.31 for men and women, respectively; P ≤ .03).

CONCLUSIONS

This first large-scale population study shows that me-NAM, as an indicator of NNMT activity, is strongly associated with obesity and diabetes, supporting NNMT as a potential target for treating obesity and diabetes in humans.

Epidermal Fatty Acid binding protein promotes skin inflammation induced by high-fat diet

Defining specific cellular and molecular mechanisms in most obesity-related diseases remains an important challenge. Here we report a serendipitous finding that consumption of a high-fat diet (HFD) greatly increased the occurrence of skin lesions in C57BL/6 mice. We demonstrated that HFD induced the accumulation of a specific type of CD11c(+) macrophages in skin preceding detectable lesions. These cells primed skin to induce IL-1β and IL-18 signaling, which further promoted the cytokines IFN-γ- and IL-17-mediated skin inflammation. Mechanistically, epidermal fatty acid binding protein (E-FABP) was significantly upregulated in skin of obese mice, which coupled lipid droplet formation and NLRP3 inflammasome activation. Deficiency of E-FABP in obese mice decreased recruitment of CD11c(+) macrophages in skin tissues, reduced production of IL-1β and IL-18, and consequently dampened activation of effector T cells. Furthermore, E-FABP-deficient mice are completely resistant to HFD-induced skin lesions. Collectively, E-FABP represents a molecular sensor triggering HFD-induced skin inflammation.

Short sleep duration as a risk factor for childhood overweight/obesity: a large multicentric epidemiologic study in China

OBJECTIVES AND SETTING

The present study was designed to examine the association of sleep duration with obesity/overweight in a multicentric urban sample of Chinese children.

PARTICIPANTS AND DESIGN

A random sample of 17,696 children aged 7.00-11.99 years participated in a cross-sectional multicentric survey.

MEASUREMENTS

The Chinese version of the Children's Sleep Habits Questionnaire was used to collect information on children's sleep behaviors. Body mass index (BMI) was calculated as weight (kilograms)/height squared (square meters). Sex, age, and BMI were used to define overweight and obesity based on the definition recommended by the Working Group on Obesity in China.

RESULTS

The prevalence of obesity and overweight in Chinese school-aged children was 10.7% and 10.3%, respectively. Hierarchical multiple linear regression models revealed a significant association between shorter sleep duration (hours/day) and increased BMI (β = -0.120; P = .019). Multivariate logistic regression models demonstrated that, compared with sleep duration ≥10 hours/d, mean sleep duration <9 hours/d experienced increased likelihood of overweight/obesity (odds ratio = 1.21; P = .005). Moreover, sleep-schedule variability, independent of sleep duration, was found to be associated with overweight/obesity (odds ratio = 1.11; P = .016).

CONCLUSIONS

Sleep duration and sleep-schedule variability, along with television viewing, homework schedule, and snack eating, were linked to overweight/obesity among elementary school children in this population-based sample.

Black ginseng extract ameliorates hypercholesterolemia in rats

Background

Ginseng (Panax ginseng Meyer) is a well-characterized medicinal herb listed in the classic oriental herbal dictionary as “Shin-nong-bon-cho-kyung.” Ginseng has diverse pharmacologic and therapeutic properties. Black ginseng (BG, Ginseng Radix nigra) is produced by repeatedly steaming fresh ginseng nine times. Studies of BG have shown that prolonged heat treatment enhances the antioxidant activity with increased radical scavenging activity. Several recent studies have showed the effects of BG on increased lipid profiles in mice. In this study report the effects of water and ethanol extracts of BG on hypercholesterolemia in rats. To our knowledge, this is the first time such an effect has been reported.

Methods

Experiments were conducted on male Sprague Dawley rats fed with a high-cholesterol diet supplemented with the water and ethanol extracts of BG (200 mg/kg). Their blood cholesterol levels, serum white blood cell levels, and cholesterol-metabolizing marker genes messenger RNA (mRNA) expression were determined. Liver and adipose tissues were histologically analyzed.

Results

We found that BG extracts efficiently reduced the total serum cholesterol levels, low-density lipoprotein (LDL) levels with increased food efficiency ratio and increased number of neutrophil cells. It also attenuated the key genes responsible for lipogenesis, that is, acetyl-coenzyme A (CoA) acetyltransferase 2, 3-hydroxy-3-methyl-glutaryl-CoA reductase, and sterol regulatory element-binding protein 2, at the mRNA level inside liver cells. Furthermore, the BG extract also reduced the accumulation of fat in adipose tissues, and inhibited the neutral fat content in liver cells stained with hematoxylin and eosin and oil red O.

Conclusion

Administration of BG extracts to Sprague Dawley rats fed with high-cholesterol diet ameliorated hypercholesterolemia, which was mediated via modulation of cholesterol-metabolizing marker genes. This data throw a light on BG's cardioprotective effects.

The Epidemiology of Obesity: A Big Picture

The epidemic of overweight and obesity presents a major challenge to chronic disease prevention and health across the life course around the world. Fueled by economic growth, industrialization, mechanized transport, urbanization, an increasingly sedentary lifestyle, and a nutritional transition to processed foods and high-calorie diets over the last 30 years, many countries have witnessed the prevalence of obesity in its citizens double and even quadruple. A rising prevalence of childhood obesity, in particular, forebodes a staggering burden of disease in individuals and healthcare systems in the decades to come. A complex, multifactorial disease, with genetic, behavioral, socioeconomic, and environmental origins, obesity raises the risk of debilitating morbidity and mortality. Relying primarily on epidemiologic evidence published within the last decade, this non-exhaustive review discusses the extent of the obesity epidemic, its risk factors-known and novel-, sequelae, and economic impact across the globe.

Energy Intake, Profile, and Dietary Sources in the Spanish Population: Findings of the ANIBES Study

Energy intake, and the foods and beverages contributing to that, are considered key to understanding the high obesity prevalence worldwide. The relative contributions of energy intake and expenditure to the obesity epidemic, however, remain poorly defined in Spain. The purpose of this study was to contribute to updating data of dietary energy intake and its main sources from food and beverages, according to gender and age. These data were derived from the ANIBES ("Anthropometry, Intake, and Energy Balance in Spain") study, a cross-sectional study of a nationally representative sample of the Spanish population (from 9-75 years old). A three-day dietary record, collected by means of a tablet device, was used to obtain information about food and beverage consumption and leftovers. The final sample comprised 2009 individuals (1,013 men, 996 women). The observed mean dietary energy intake was 7.6 ± 2.11 MJ/day (8.2 ± 2.22 MJ/day for men and 6.9 ± 1.79 MJ/day for women). The highest intakes were observed among adolescents aged 13-17 years (8.4 MJ/day), followed by children 9-12 years (8.2 ± 1.80 MJ/day), adults aged 18-64 (7.6 ± 2.14 MJ/day) and older adults aged 65-75 years (6.8 ± 1.88 MJ/day). Cereals or grains (27.4%), meats and derivatives (15.2%), oils and fats (12.3%), and milk and dairy products (11.8%) contributed most to daily energy intake. Energy contributions from non-alcoholic beverages (3.9%), fish and shellfish (3.6%), sugars and sweets (3.3%) and alcoholic beverages (2.6%) were moderate to minor. Contributions to caloric profile were 16.8%E from proteins; 41.1%E from carbohydrates, including 1.4%E from fiber; 38.5%E from fats; and 1.9%E from alcohol intake. We can conclude that energy intake is decreasing in the Spanish population. A variety of food and beverage groups contribute to energy intake; however, it is necessary to reinforce efforts for better adherence to the traditional Mediterranean diet.

The intake of high-fat diets induces the acquisition of brown adipocyte gene expression features in white adipose tissue

BACKGROUND/OBJECTIVE

White-to-brown adipose tissue remodeling (browning) in response to different stimuli constitutes an active research area for obesity treatment. The emergence in traditional white adipose tissue (WAT) depots of multilocular adipocytes that express uncoupling protein 1 (UCP1) and resemble brown adipocytes, the so called 'brite' adipocytes, could contribute to increased energy expenditure. In rodents, obesogenic stimuli such as the intake of hyperlipidic diets can increase brown adipose tissue (BAT) thermogenic capacity and contribute to maintaining body weight. The aim of this study was to investigate the potential of two different hyperlipidic diets, a commercial high-fat (HF) diet and a highly palatable cafeteria (CAF) diet, to induce WAT browning.

METHODS

We analyzed gene expression of a wide number of brown/brite adipocyte markers in different WAT depots, in BAT and in peripheral blood mononuclear cells (PBMCs) increasingly being used in nutrition studies as a potential source of biomarkers of physiological effects. We also performed morphological analysis of adipose tissue.

RESULTS

Both HF diets studied were able to increase the expression of the markers studied in WAT in a depot-specific manner, as well as in BAT; some of these changes were also reflected in PBMCs. This increased browning capacity was translated into the appearance of UCP1- and CIDE-A (cell death-inducing DFFA-like effector A)-positive brite adipocytes in retroperitoneal WAT. Administration of the CAF diet, associated with higher adiposity, produced the strongest impact on the parameters studied while its withdrawal restored basal conditions.

CONCLUSIONS

Acquisition of brown adipocyte features in WAT could evidence an adaptation to try to counteract increased adiposity due to the intake of HF diets. Additionally, PBMCs could constitute an interesting easily obtainable material to assess the effect of nutritional interventions on browning capacity.

Early leptin intervention reverses perturbed energy balance regulating hypothalamic neuropeptides in the pre- and postnatal calorie-restricted female rat offspring

Pre- and postnatal calorie restriction is associated with postnatal growth restriction, reduced circulating leptin concentrations, and perturbed energy balance. Hypothalamic regulation of energy balance demonstrates enhanced orexigenic (NPY, AgRP) and diminished anorexigenic (POMC, CART) neuropeptide expression (PN21), setting the stage for subsequent development of obesity in female Sprague-Dawley rats. Leptin replenishment during the early postnatal period (PN2-PN8) led to reversal of the hypothalamic orexigenic:anorexigenic neuropeptide ratio at PN21 by reducing only the orexigenic (NPY, AgRP), without affecting the anorexigenic (POMC, CART) neuropeptide expression. This hypothalamic effect was mediated via enhanced leptin receptor (ObRb) signaling that involved increased pSTAT3/STAT3 but reduced PTP1B. This was further confirmed by an increase in body weight at PN21 in response to intracerebroventricular administration of antisense ObRb oligonucleotides (PN2-PN8). The change in the hypothalamic neuropeptide balance in response to leptin administration was associated with increased oxygen consumption, carbon dioxide production, and physical activity, which resulted in increased milk intake (PN14) with no change in body weight. This is in contrast to the reduction in milk intake with no effect on energy expenditure and physical activity observed in controls. We conclude that pre- and postnatal calorie restriction perturbs hypothalamic neuropeptide regulation of energy balance, setting the stage for hyperphagia and reduced energy expenditure, hallmarks of obesity. Leptin in turn reverses this phenotype by increasing hypothalamic ObRb signaling (sensitivity) and affecting only the orexigenic arm of the neuropeptide balance.

Brown adipose tissue and thermogenesis

The growing understanding of adipose tissue as an important endocrine organ with multiple metabolic functions has directed the attention to the (patho)physiology of distinct fat depots. Brown adipose tissue (BAT), in contrast to bona fide white fat, can dissipate significant amounts of chemical energy through uncoupled respiration and heat production (thermogenesis). This process is mediated by the major thermogenic factor uncoupling protein-1 and can be activated by certain stimuli, such as cold exposure, adrenergic compounds or genetic alterations. White adipose tissue (WAT) depots, however, also possess the capacity to acquire brown fat characteristics in response to thermogenic stimuli. The induction of a BAT-like cellular and molecular program in WAT has recently been termed "browning" or "beiging". Promotion of BAT activity or the browning of WAT is associated with in vivo cold tolerance, increased energy expenditure, and protection against obesity and type 2 diabetes. These preclinical observations have gained additional significance with the recent discovery that active BAT is present in adult humans and can be detected by 18fluor-deoxy-glucose positron emission tomography coupled with computed tomography. As in rodents, human BAT can be activated by cold exposure and is associated with increased energy turnover and lower body fat mass. Despite the tremendous progress in brown fat research in recent years, pharmacological concepts to harness BAT function therapeutically are currently still lacking.

Predictors of Energy Compensation during Exercise Interventions: A Systematic Review

Weight loss from exercise-induced energy deficits is usually less than expected. The objective of this systematic review was to investigate predictors of energy compensation, which is defined as body energy changes (fat mass and fat-free mass) over the total amount of exercise energy expenditure. A search was conducted in multiple databases without date limits. Of 4745 studies found, 61 were included in this systematic review with a total of 928 subjects. The overall mean energy compensation was 18% ± 93%. The analyses indicated that 48% of the variance of energy compensation is explained by the interaction between initial fat mass, age and duration of exercise interventions. Sex, frequency, intensity and dose of exercise energy expenditure were not significant predictors of energy compensation. The fitted model suggested that for a shorter study duration, lower energy compensation was observed in younger individuals with higher initial fat mass (FM). In contrast, higher energy compensation was noted for younger individuals with lower initial FM. From 25 weeks onward, energy compensation was no longer different for these predictors. For studies of longer duration (about 80 weeks), the energy compensation approached 84%. Lower energy compensation occurs with short-term exercise, and a much higher level of energy compensation accompanies long-term exercise interventions.

Food and physical activity environments: an energy balance approach for research and practice

Increases in the prevalence of overweight and obesity are a function of chronic, population-level energy imbalance, whereby energy intakes exceed energy expenditures. Although sometimes viewed in isolation, energy intakes and expenditures in fact exist in a dynamic interplay: energy intakes may influence energy expenditures and vice versa. Obesogenic environments that promote positive energy balance play a central role in the obesity epidemic, and reducing obesity prevalence will require re-engineering environments to promote both healthy eating and physical activity. There may be untapped synergies in addressing both sides of the energy balance equation in environmentally focused obesity interventions, yet food/beverage and physical activity environments are often addressed separately. The field needs design, evaluation, and analytic methods that support this approach. This paper provides a rationale for an energy balance approach and reviews and describes research and practitioner work that has taken this approach to obesity prevention at the environmental and policy levels. Future directions in research, practice, and policy include moving obesity prevention toward a systems approach that brings both nutrition and physical activity into interdisciplinary training, funding mechanisms, and clinical and policy recommendations/guidelines.

Cognitive and typing outcomes measured simultaneously with slow treadmill walking or sitting: implications for treadmill desks

Purpose

This study compared cognitive (attention, learning, and memory) and typing outcomes during slow treadmill walking or sitting. Seventy-five healthy individuals were randomly assigned to a treadmill walking group (n=37; 23 female) or sitting group (n=38; 17 female).

Methods

The treadmill walking group completed a series of tests while walking at 1.5 mph. The sitting group performed the same tests while sitting at a standard desk. Tests performed by both groups included: the Rey Auditory Verbal Learning Test and a modified version of the Paced Auditory Serial Attention Test. In addition, typing performance was evaluated.

Results

Participants in the treadmill walking group performed worse on the Rey Auditory Verbal Learning Test for total learning than the sitting group; the main effect was significant (F(1,73)=4.75, p=0.03, η_p²=0.06); however, short- and long-delay recall performance did not differ between groups (p>0.05). For the Paced Auditory Serial Attention Test, total number of correct responses was lower in the treadmill walking group relative to the sitting group; the main effect was significant (F(1,73)=4.97, p=0.03, η_p²=0.06). The performance of both groups followed the same learning slope (Group x Trial interactions were not significant) for the Rey Auditory Verbal Learning Test and Paced Auditory Serial Attention Test. Individuals in the treadmill walking group performed significantly worse for all measures of typing (p<0.05).

Conclusion

Walking on a treadmill desk may result in a modest difference in total learning and typing outcomes relative to sitting, but those declines may not outweigh the benefit of the physical activity gains from walking on a treadmill.

JTP-103237, a novel monoacylglycerol acyltransferase inhibitor, modulates fat absorption and prevents diet-induced obesity

Monoacylglycerol acyltransferase 2 (MGAT2) plays an important role in intestinal fat absorption. We discovered the novel MGAT2 inhibitor, JTP-103237, and evaluated its pharmacological profile. JTP-103237 selectively inhibited MGAT2 without remarkable species differences and reduced absorbed lipids in circulation. After lipid administration, JTP-103237 slightly but significantly decreased triglyceride content in proximal small intestine and significantly increased the lipids content in the distal small intestine. In addition, JTP-103237 significantly increased MGAT substrate (monoacylglycerol and fatty acid) content in the small intestine. JTP-103237 increased plasma peptide YY levels after lipid loading and reduced food intake in a dietary fat-dependent manner. After chronic treatment, JTP-103237 significantly decreased body weight and increased O2 consumption in the early dark phase in high fat diet induced obese (DIO) mice. Moreover, JTP-103237 improved glucose tolerance and decreased fat weight and hepatic triglyceride content in DIO mice. Our findings indicate that JTP-103237 prevents diet-induced obesity by inhibiting intestinal MGAT2 and has unique properties as a drug for the treatment of obesity.