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Steroid hormones are crucial regulators of life-stage transitions during development in animals. However, the molecular mechanisms by which developmental transition through these stages is coupled with optimal metabolic homeostasis remains poorly understood. Here, we demonstrate through mathematical modelling and experimental validation that ecdysteroid-induced metabolic remodelling from resource consumption to conservation can be a successful life-history strategy to maximize fitness in Drosophila larvae in a fluctuating environment. Specifically, the ecdysteroid-inducible protein ImpL2 protects against hydrolysis of circulating trehalose following pupal commitment in larvae. Stored glycogen and triglycerides in the fat body are also conserved, even under fasting conditions. Moreover, pupal commitment dictates reduced energy expenditure upon starvation to maintain available resources, thus negotiating trade-offs in resource allocation at the physiological and behavioural levels. The optimal stage-specific metabolic shift elucidated by our predictive and empirical approaches reveals that Drosophila has developed a highly controlled system for ensuring robust development that may be conserved among higher-order organisms in response to intrinsic and extrinsic cues.

The ability to control one's personal microclimate allows for customized comfort, reduced energy expenditure, and better human performance. Here we present the design of a multi-zone user-controllable heated jacket. The garment uses a multi-layer textile approach to provide e-textile heating and thermal insulation. Heating zones are controlled by the user through a sleeve-mounted multi-sensor e-textile interface. A custom textile-integrated 3D printed strain-relief support protects the interface and provides a counter-force for manual interaction. The garment is designed for everyday wearability in a physical and aesthetic form intended to blend in with everyday clothing.

Due to the COVID-19 pandemic, in December 2020, the Italian government established a second home confinement during the Christmas holidays. These restrictions offered the opportunity to utilize a well-defined model for observing the consequences of lifestyle changes of healthy individuals. This study aimed at estimating in healthy subjects from Southern Italy the physical activity (PA), the presence and the severity of gastrointestinal (GI) symptoms, and the association between the possible worsening of GI health status and the PA levels. An adapted version of the International PA Questionnaire-short form (IPAQ-SF) and the Gastrointestinal Symptom Rating Scale (GSRS) were proposed through Google’s online survey platform in three different periods via WhatsAppTM to 499 healthy subjects (62% females) from Apulia (25%), Calabria (37%), and Campania (38%). Our results showed statistically significant changes during the home confinement: reduced energy expenditure (EE) among overweight subjects (−239.82, 95%CI −405.74, −73.89) or those who had high GSRS total score (−1079.54, 95%CI −2027.43, −131.66). An increase in GSRS total score was observed in overweight subjects, reaching statistical significance in those from Campania. Our study supports the importance of PA to reduce health risks, including those related to the possible onset of GI tract diseases.

Weight regain after weight loss is a well-described phenomenon in both humans and animal models of obesity. Reduced energy expenditure and increased caloric intake are considered the main drivers of weight regain. We hypothesized that adipose tissue with obesity memory (OM) has a tissue-autonomous lipolytic defect, allowing for increased efficiency of lipid storage. We utilized a mouse model of diet-induced obesity, which was subjected to 60% caloric restriction to achieve lean body weight, followed by a short period of high-fat diet (HFD) rechallenge. Age-matched lean mice fed HFD for the first time were used as the control group. Upon rechallenge with HFD, mice with OM had higher respiratory exchange ratios than lean mice with no OM despite comparable body weight, suggesting higher utilization of glucose over fatty acid oxidation. White adipose tissue explants with OM had comparable lipolytic response after caloric restriction; however, reduced functional lipolytic response to norepinephrine was noted as early as 5 days after rechallenge with HFD and was accompanied by reduction in hormone-sensitive lipase serine phosphorylation. The relative lipolytic defect was associated with increased expression of inflammatory genes and a decrease in adrenergic receptor genes, most notably Adrb3. Taken together, white adipose tissue of lean mice with OM shows increased sensitization to HFD compared with white adipose tissue with no OM, rendering it resistant to catecholamine-induced lipolysis. This relative lipolytic defect is tissue-autonomous and could play a role in the rapid weight regain observed after weight loss.

The goal of this paper is to provide a review of recent work on the use of wearable devices for measuring physical activity (PA) in the elderly. In older adults, PA is related to independence in activities of daily living and maintaining a good quality of life. With aging, there is a reduction in PA, which may explain reduced energy expenditure (EE) during rest and PA. In addition, there is also a reduction in the spatial extent of mobility (life-space). Sensors used for measuring PA include pedometers, uni-axial, bi-axial and tri-axial accelerometers, heart rate monitors combined with accelerometers, and complex systems using multiple types of sensors. Wearable sensors are accurate at measuring step counts, PA intensity, and EE, but need to improve accuracy of measuring type of PA, spatial extent of PA, and measuring non-ambulatory PA. Clear standards for measurement, algorithms used for computing clinically relevant measures, need to be developed.

Obesity is an extremely resilient condition. Weight loss is most challenging, and weight recidivism is rampant. There is accumulating evidence highlighting that energy deficits meant to produce increased mobilization of energy stores trigger a number of somewhat persistent adaptations that together increase the drive to eat and decrease energy output. These adaptations ostensibly enable a context where the likelihood of energy compensation is heightened. In fact, energy compensation is present for both diet and exercise induced energy deficits although at different magnitudes. For the most part, the energy compensation in response to exercise induced energy deficits seems to be larger. Interestingly, energy compensation appears to be greater for longer interventions, an effect independent of whether the energy deficit is induced through diet or exercise. The latter suggests that the increased drive to eat and the reduced energy expenditure that accompany weight loss might be successfully fought off initially. However, with time there seems to be increasing erosion of the behaviours that initially opposed adaptations to weight loss and increased energy compensation progressively sets in. Under such conditions, it would seem prudent to propose weight loss targets that align with a level of behaviour modifications that can be sustained indefinitely.

Athlete participation in the Paralympic games is steadily increasing; prompting research focused on the unique needs of this population. While the Paralympic Games includes a diversity of athletes, athletes with a spinal cord injury (PARA-SCI) represent a subgroup that requires specialized recommendations. Nutritional guidelines designed to optimize performance, in the context of the neurological impairments, are required. This narrative review summarizes the current literature regarding the importance of dietary protein for optimal health and performance. Factors with the potential to affect protein needs in PARA-SCI including loss of active muscle mass, reduced energy expenditure, and secondary complications are examined in detail. Furthermore, we analyze protein intakes in PARA-SCI from the available research to provide context around current practices and trends. In conclusion, we make the case that protein recommendations for able-bodied athletes may not be directly transferable to PARA-SCI. Consequently, PARA-SCI need their own guidelines to maximize performance and ensure long-term health.

Homeothermy requires increased metabolic rates as temperatures decline below the thermoneutral zone, so homeotherms typically select microhabitats within or near their thermoneutral zones during periods of inactivity. However, many mammals and birds are heterotherms that relax internal controls on body temperature when maintaining a high, stable body temperature is energetically costly. Such heterotherms should be less tied to microhabitats near their thermoneutral zones, and because heterotherms spend more time in torpor and expend less energy at colder temperatures, heterotherms may even select microhabitats in which temperatures are well below their thermoneutral zones. We studied how temperature and daily torpor influence selection of diurnal roosts by a heterothermic bat (Myotis thysanodes). We (1) quantified the relationship between ambient temperature and daily duration of torpor, (2) simulated daily energy expenditure over a range of microhabitat (roost) temperatures, and (3) quantified the influence of roost temperature on roost selection. While warm roosts substantially reduced energy expenditure of simulated homeothermic bats, heterothermic bats modulated their use of torpor to maintain a constant level of energy expenditure over the course of a day. Daily torpor expanded the range of energetically economical microhabitats, such that roost selection was independent of roost temperature. Our work adds to a growing literature documenting functions of torpor beyond its historical conceptualization as a last-resort measure to save energy during extended or acute energetic stress.

Burst-and-coast swimming is an intermittent mode of locomotion used by various fish species. The intermittent gait has been associated with certain advantages such as stabilizing the visual field, improved sensing ability, and reduced energy expenditure. We investigate burst-coast swimming in rummy nose tetra fish (Hemigrammus bleheri) using a combination of experimental data and numerical simulations. The experiments were performed in a shallow water channel where the tetra fish swam against an imposed inflow. High speed video recordings of the fish were digitized to extract the undulatory kinematics at various swimming speeds. The kinematics data were then used in Navier–Stokes simulations to prescribe the undulatory motion for three-dimensional geometrical models of the fish. The resulting steady-state speeds of the simulated self-propelled swimmers agree well with the speeds observed experimentally. We examine the power requirements for various realistic swimming modes, which indicate that it is possible to use continuous swimming gaits that require considerably less mechanical energy than intermittent burst-coast modes at comparable speeds. The higher energetic cost of burst-coast swimming suggests that the primary purpose of intermittent swimming may not be to conserve energy, but it may instead be related to a combination of other functional aspects such as improved sensing and the likely existence of a minimum tail-beat frequency. Importantly, using sinusoidal traveling waves to generate intermittent and continuous kinematics, instead of using experiment-based kinematics, results in comparable power requirements for the two swimming modes.

Management practices matter for firm performance. As energy is one input in firm production, management practices may interact with energy use. Using a comprehensive firm-level database covering 31 countries, this study documents the link between structured management practices, energy use, and firm performance. The paper reports several findings. First, although management is negatively correlated with energy expenditure, it bears a positive (or null) relationship with physical energy use, suggesting that management effort is directed toward saving costs but not reducing environmental impact. These results are primarily driven by the manufacturing sector. Second, among the structured management practices examined, those relating to target-setting are associated with reduced energy expenditure intensity. Third, generic management practices are correlated with greater discipline around energy management. Finally, while generic practices are correlated with stronger firm performance in manufacturing and services, energy-centric practices show a positive association only in services. Vast heterogeneity in adoption and outcomes suggests that targeted approaches to encourage energy management practices in firms may be more effective than uniform ones.

Background In common with many other low- and middle-income countries (LMICs), rural to urban migrants in India are at increased risk of obesity, but it is unclear whether this is due to increased energy intake, reduced energy expenditure, or both. Knowing this and the relative contribution of specific dietary and physical activity behaviours to greater adiposity among urban migrants could inform policies for control of the obesity epidemic in India and other urbanising LMICs. In the Indian Migration Study, we previously found that urban migrants had greater prevalence of obesity and diabetes compared with their nonmigrant rural-dwelling siblings. In this study, we investigated the relative contribution of energy intake and expenditure and specific diet and activity behaviours to greater adiposity among urban migrants in India. Methods and findings The Indian Migration Study was conducted between 2005 and 2007. Factory workers and their spouses from four cities in north, central, and south of India, together with their rural-dwelling siblings, were surveyed. Self-reported data on diet and physical activity was collected using validated questionnaires, and adiposity was estimated from thickness of skinfolds. The association of differences in dietary intake, physical activity, and adiposity between siblings was examined using multivariable linear regression. Data on 2,464 participants (median age 43 years) comprised of 1,232 sibling pairs (urban migrant and their rural-dwelling sibling) of the same sex (31% female) were analysed. Compared with the rural siblings, urban migrants had 18% greater adiposity, 12% (360 calories/day) more energy intake, and 18% (11 kilojoules/kg/day) less energy expenditure (P < 0.001 for all). Energy intake and expenditure were independently associated with increased adiposity of urban siblings, accounting for 4% and 6.5% of adiposity difference between siblings, respectively. Difference in dietary fat/oil (10 g/day), time spent engaged in moderate or vigorous activity (69 minutes/day), and watching television (30 minutes/day) were associated with difference in adiposity between siblings, but no clear association was observed for intake of fruits and vegetables, sugary foods and sweets, cereals, animal and dairy products, and sedentary time. The limitations of this study include a cross-sectional design, systematic differences in premigration characteristics of migrants and nonmigrants, low response rate, and measurement error in estimating diet and activity from questionnaires. Conclusions We found that increased energy intake and reduced energy expenditure contributed equally to greater adiposity among urban migrants in India. Policies aimed at controlling the rising prevalence of obesity in India and potentially other urbanising LMICs need to be multicomponent, target both energy intake and expenditure, and focus particularly on behaviours such as dietary fat/oil intake, time spent on watching television, and time spent engaged in moderate or vigorous intensity physical activity., Sanjay Kinra and colleagues assess the link between urbanisation and increased obesity in India, Author summary Why was the study done? People who migrate from villages to towns and cities in India and many other developing countries have more body fat, but whether this is because of more energy intake or less expenditure or both is unclear. Knowing this, and the contribution of specific diet and activity behaviours, would help policy makers to develop programmes to control the rise in obesity in India and possibly other developing countries. In the Indian Migration Study, we previously found that urban migrants have more obesity and diabetes compared with their siblings who still live in villages. What did the researchers do and find? In the Indian Migration Study, conducted between 2005 and 2007, we collected data on urban factory workers and their spouses in four cities in India, together with their siblings who were still living in a rural area. Data on diet, activity, and obesity for 2,464 participants (1,232 sibling pairs of the same sex) at an average age of 43 years (30% females) were analysed. We found that energy intake and expenditure contributed equally to greater body fat in urban migrants; fat/oil intake, time spent watching television, and performing moderate or vigorous intensity physical activity were found to be the most important behaviours contributing to greater adiposity of urban migrants. What do these findings mean? Energy intake and expenditure contribute equally to the increased body fat of urban migrants in India; behaviours such as fat/oil intake, time spent on watching television and performing moderate or vigorous intensity physical activity contributed most to more body fat among urban migrants. Programs for controlling the rise of obesity in India and possibly other developing countries should be multicomponent and target these behaviours that we have identified.

‘Imperial Satiety Protocol’ (I-SatPro) is a new multifaceted approach to weight loss for people with obesity (PwO), encompassing dietary advice, time-restricted eating, physical activity and coaching to support behaviour change. Participants (n = 84) attended fortnightly I-SatPro group sessions for 30 weeks, with 70% of participants completing. On completion at 30 weeks, the mean weight loss was 15.2 ± 1.1 kg (13.2 ± 0.8% from baseline, P

Obesity became an epidemic public health problem and continuously increasing every year. For the longest time, the pathologic framework for obesity had been simple: caloric intake is greater than the energy output, which by far still true, however, the underlying reasons for increased energy intake and reduced energy expenditure remain largely unknown. Emerging data indicate that obesity can be oftentimes secondary to an underlying pathology, which can be due to genetics, inflammation, microbiome dysbiosis, metabolism, drugs and several other reasons. In this chapter, we described the pathology of obesity and underlying factors are linked or contributing in its progression.

Excessive energy intake and reduced energy expenditure drive the development of insulin resistance and metabolic diseases such as obesity and type 2 diabetes mellitus. Metabolic signals derived from dietary intake or secreted from adipose tissue, gut, and liver contribute to energy homeostasis. Recent metabolomic studies identified novel metabolites and enlarged our knowledge on classic metabolites. This review summarizes the evidence of their roles as mediators of interorgan crosstalk and regulators of insulin sensitivity and energy metabolism. Circulating lipids such as free fatty acids, acetate, and palmitoleate from adipose tissue and short-chain fatty acids from the gut effectively act on liver and skeletal muscle. Intracellular lipids such as diacylglycerols and sphingolipids can serve as lipotoxins by directly inhibiting insulin action in muscle and liver. In contrast, fatty acid esters of hydroxy fatty acids have been recently shown to exert a series of beneficial effects. Also, ketoacids are gaining interest as potent modulators of insulin action and mitochondrial function. Finally, branched-chain amino acids not only predict metabolic diseases, but also inhibit insulin signaling. Here, we focus on the metabolic crosstalk in humans, which regulates insulin sensitivity and energy homeostasis in the main insulin-sensitive tissues, skeletal muscle, liver, and adipose tissue.

Metabolism Measurements of total and basal energy in a large cohort of subjects at ages spanning from before birth to old age document distinct changes that occur during a human lifetime. Pontzer et al. report that energy expenditure (adjusted for weight) in neonates was like that of adults but increased substantially in the first year of life (see the Perspective by Rhoads and Anderson). It then gradually declined until young individuals reached adult characteristics, which were maintained from age 20 to 60 years. Older individuals showed reduced energy expenditure. Tissue metabolism thus appears not to be constant but rather to undergo transitions at critical junctures. Science , abe5017, this issue p. [808][1]; see also abl4537, p. [738][2] [1]: /lookup/doi/10.1126/science.abe5017 [2]: /lookup/doi/10.1126/science.abl4537

Objectives This systematic review and meta-analysis determined the effects of using an exoskeleton during occupational tasks on physical stress and strain compared to not using an exoskeleton. Methods Systematic electronic database searches were performed and the review was prepared according to the PRISMA guidelines. Treatment effects on the predefined outcomes were calculated using standardized mean differences for continuous outcomes in several meta-analyses using Review Manager 5.3. Registration: PROSPERO (CRD42020168701). Results 63 articles were included in qualitative syntheses and 52 in quantitative, but most of them did not extensively evaluate musculoskeletal stress and strain and the risk of bias was rated high for all included studies. Statistically significant effects of using back, upper-limb, or lower-limb exoskeletons have been observed in the supported body areas (e.g. reduced muscle activity, joint moments and perceived strain). Studies which did not exclusively focus on the supported body area also showed statistically significant effects in the non-supported areas (e.g. changed muscle activity and perceived strain) and in physiological outcomes (e.g. reduced energy expenditure). Conclusions Using an exoskeleton during occupational tasks seems to reduce user's acute physical stress and strain in the exoskeleton's target area. However, impact on workers' health is still unknown, primarily because of missing long-term evaluations under real working conditions. Furthermore , this systematic review highlights a lack of studies (1) following high quality methodological criteria, (2) evaluating various inter-related stress and strain parameters instead of only focusing on one specific, and (3) evaluating non-target body areas instead of only the directly supported body area.

The Paralympic movement is growing in popularity, resulting in increased numbers of athletes with a spinal cord injury (SCI) competing in various sport disciplines. Athletes with an SCI require specialized recommendations to promote health and to maximize performance, as evidenced by their metabolic and physiological adaptations. Nutrition is a key factor for optimal performance; however, scientifically supported nutritional recommendations are limited. This review summarizes the current knowledge regarding the importance of carbohydrates (CHO) for health and performance in athletes with an SCI. Factors possibly affecting CHO needs, such as muscle atrophy, reduced energy expenditure, and secondary complications are analyzed comprehensively. Furthermore, a model calculation for CHO requirements during an endurance event is provided. Along with assessing the effectiveness of CHO supplementation in the athletic population with SCI, the evaluation of their CHO intake from the available research supplies background to current practices. Finally, future directions are identified. In conclusion, the direct transfer of CHO guidelines from able‐bodied (AB) athletes to athletes with an SCI does not seem to be reasonable. Based on the critical role of CHOs in exercise performance, establishing recommendations for athletes with an SCI should be the overall objective for prospective research., Nutrients, 13 (7), ISSN:2072-6643

This review examines the metabolic adaptations that occur in response to negative energy balance and their potential putative or functional impact on appetite and food intake. Sustained negative energy balance will result in weight loss, with body composition changes similar for different dietary interventions if total energy and protein intake are equated. During periods of underfeeding, compensatory metabolic and behavioural responses occur that attenuate the prescribed energy deficit. While losses of metabolically active tissue during energy deficit result in reduced energy expenditure, an additional down-regulation in expenditure has been noted that cannot be explained by changes in body tissue (e.g. adaptive thermogenesis). Sustained negative energy balance is also associated with an increase in orexigenic drive and changes in appetite-related peptides during weight loss that may act as cues for increased hunger and food intake. It has also been suggested that losses of fat-free mass (FFM) could also act as an orexigenic signal during weight loss, but more data are needed to support these findings and the signalling pathways linking FFM and energy intake remain unclear. Taken together, these metabolic and behavioural responses to weight loss point to a highly complex and dynamic energy balance system in which perturbations to individual components can cause co-ordinated and inter-related compensatory responses elsewhere. The strength of these compensatory responses is individually subtle, and early identification of this variability may help identify individuals that respond well or poorly to an intervention.

Obesity prevalence has increased, and increased energy intake or decreased physical activity are the two most obvious contributing factors. The percentage of Americans engaging in exercise has been stable over the past few decades, but decreases in occupation-related energy expenditure are sufficient to partially explain increased obesity prevalence. Further, the contribution of energy intake and energy expenditure to the obesity epidemic is complicated because they are not independent-they are influenced by each other. For example, Mayer found that low activity levels were marked by higher body weight and higher "unregulated" energy intake levels. Conversely, higher activity levels were marked by lower body weight and energy intake that matched energy expenditure. Consistent with Mayer, we propose that because most Americans have low levels of occupation-related activity, they do not benefit from the regulation of energy intake achieved at higher activity levels, resulting in weight gain due to energy intake exceeding energy expenditure.

In tackling the obesity pandemic, considerable efforts are devoted to the development of effective weight reduction strategies, yet many dieting individuals fail to maintain a long-term weight reduction, and instead undergo excessive weight regain cycles. The mechanisms driving recurrent post-dieting obesity remain largely elusive. Here we identify an intestinal microbiome signature that persists after successful dieting of obese mice and contributes to faster weight regain and metabolic aberrations upon re-exposure to obesity-promoting conditions. Faecal transfer experiments show that the accelerated weight regain phenotype can be transmitted to germ-free mice. We develop a machine-learning algorithm that enables personalized microbiome-based prediction of the extent of post-dieting weight regain. Additionally, we find that the microbiome contributes to diminished post-dieting flavonoid levels and reduced energy expenditure, and demonstrate that flavonoid-based 'post-biotic' intervention ameliorates excessive secondary weight gain. Together, our data highlight a possible microbiome contribution to accelerated post-dieting weight regain, and suggest that microbiome-targeting approaches may help to diagnose and treat this common disorder.

Work place is an important dimension that expedite the activity and exerts minimum stress on the workers. Therefore work space must get considerable attention in the designing of the layout. considering the importance of kitchen platform, there is need to design kitchen and ergonomically evaluation of kitchen. A data on 200 sample of existing kitchen were randomly selected belonging to nuclear families. The data obtained was useful for designing a kitchen which gives comfort while working and reduced energy expenditure. The study was carried out through interview schedule methods and questionnaire filled; Anthropometrical observations are recorded by using measuring tape etc. The data collected were tabulated and suitable statistical tools like, frequency, average, percentage were used for analysis of data. In standing type of kitchens as the worker maintains the standing posture while working. Home maker can move quickly from washing to preparation to cooking area, so the home maker saving their time and energy. It is observed that "L-Shaped" kitchen counters were most common (57.00%) of respondents were more comfort for their work. The result of present study will be used to understand and improve work, worker and work place relationship to have healthy and safety of the home makers. This will help to minimize physical and energy cost of home makers to improve work efficiency and also to reduce heart beat of home makers.

Malaria-infected mice exhibit a range of sickness behaviours, and experience metabolic shifts and physiological pathologies that result in reduced energy expenditure. Treating sick mice with glucose increases disease tolerance by improving the physiological and behavioural symptoms of malaria infection without affecting parasite loads.

Lifestyle modification programmes based on cognitive behavioural therapy for obesity (CBT-OB) are the cornerstone of treatment for weight management. However, a subgroup of patients has difficulties adopting the lifestyle modification needed to manage their obesity, due to the powerful biological and environmental factors contrasting weight loss that promote excessive intake of food and reduced energy expenditure. In these cases, it may be useful to combine CBT-OB with weight-loss drugs or bariatric surgery (in patients with severe obesity), which have been specifically designed to address the biological obstacles to weight loss and weight maintenance. Data from some trials indicate that the association of weight-loss drugs with lifestyle modification programmes results in significantly greater weight loss than either therapy alone, because of the potentially complementary mechanisms of action of the two interventions. Similarly, some studies have shown that lifestyle modification programmes have a positive effect on weight loss following bariatric surgery. This chapter describes the rationale behind and the evidence for combining CBT-OB with weight-loss drugs or bariatric surgery and suggests practical strategies on when and how to integrate these interventions.

Background: One of the main reasons for recent scientific interest in screen-based behaviour (SB) is the relationship between SB and risk of being overweight or obese. The primary mechanism for overweight and obesity is an imbalance of energy intake versus energy expenditure and one reason for the interest in SB is its association with reduced energy expenditure relative to other activities. Objective: The aim of this study is to provide a basic overview of the level and structure of SB in Czech adolescents on the basis of age and gender while taking into account the differences between weekday and weekend screen based activities. Methods: Data from the Health Behaviour in School-aged Children (HBSC) study conducted in May-June 2010 in the Czech Republic were used. The sample consisted of 4365 Czech pupils (48.5% boys; age 11, n = 1406; age 13, n = 1446; age 15, n = 1513). Binomial logistic regression and Chi-square test of independence were used to provide basic comparison on the basis of gender and age groups. Results: The prevalence of SB rise with growing age with the most visible increase in prevalence is between ages 11 and age 13. SB is significantly more prevalent among adolescent boys compared with adolescent girls. Czech adolescents are more likely to not meet the recommendation of 2 hours for watching TV at weekends compared to weekdays. Playing computer games is more common among boys contrary to chatting online, which is more common among girls. The overall patterns of playing computer games and chatting online during weekends were similar to those at weekdays but increased. Conclusions: Most children in the Czech Republic do not meet the limit for total SB time of 4 or fewer hours while the prevalence of SB rises with growing age and at weekends. Interventions and strategies aiming at reducing SB in children focusing on the family and school environment in the Czech Republic are required.

Scent marking is an important aspect of social organization and intraspecific communication for many mammals, including solitary felids. By selecting specific micro-locations for scent marking, an individual may increase its success in defending its territory and finding mates. Few studies, however, have reported the selection of scent-marking objects and sites by wild felids. To improve our understanding of this behavior and its adaptive significance, we developed and tested a set of mutually non-exclusive hypotheses explaining selection of scent-marking objects by Eurasian lynx (Lynx lynx). We used snow tracking to locate and determine the characteristics of objects lynx used and selected for urine spraying. Lynx did not mark objects according to their availability but selected juvenile conifers and often marked the surface that was sheltered from the elements (“persistence hypothesis”). Lynx also selected for objects similar in size to lynx and objects located on straight road sections and avoided the most frequently available object types. This selection may have both promoted detectability of the messages by the conspecifics (“detection hypothesis”) and reduced energy expenditure of marking (“accessibility hypothesis”). Our study also indicated trade-offs faced by lynx, as the preferred marking objects were often not readily available. Therefore, suboptimal marking objects were sometimes used, most likely in order to maintain the high scent-marking frequency needed throughout their territory. We suggest that Eurasian lynx, and possibly other solitary felids, developed scent-marking behaviors that increase effectiveness and efficiency of their communication. Scent marking is a form of communication that serves several purposes and allows the signals of the sender to reach a receiver indirectly. Persistence and detectability of these signals can have high adaptive value for solitary felids since the signals are essential for advertising territories for competitors and mates. Although both of these uses may depend on the micro-location where scent is deposited, the majority of studies have focused only on the marking sites used by felids and not on their availability or selection. By snow tracking Eurasian lynx, we showed that scent-marking sites most often used are not necessarily the same as the sites selected. We also provide insights into possible adaptive features of felid scent-marking and the possible mechanisms behind the selection of marking objects which likely serve to increase the effectiveness and efficiency of scent marking.

The present study defined the short- and long-term effects of left ventricular assist device (LVAD) implantation and heart transplantation (HT) on physical activity and quality of life (QoL). Forty patients (LVAD, n = 14; HT, n = 12; and heart failure [HF], n = 14) and 14 matched healthy subjects were assessed for physical activity, energy expenditure, and QoL. The LVAD and HT groups were assessed postoperatively at 4 to 6 weeks (baseline) and 3, 6, and 12 months. At baseline, LVAD, HT, and HF patients demonstrated low physical activity, reaching only 15%, 28%, and 51% of that of healthy subjects (1,603 ± 302 vs 3,036 ± 439 vs 5,490 ± 1,058 vs 10,756 ± 568 steps/day, respectively, p

International audience; The aim of the study was to assess the impact of selection for residual feed intake (RFI) on the behavioural activity of lines divergently selected for RFI during seven generations. In all, six successive batches from the seventh generation of selection were raised in collective pens equipped with a single-place electronic feeder (SEF) from 10 weeks of age to 100 kg BW. Each batch included four groups of 12 pigs: high RFI (RFI+) castrated males, RFI+ females, low RFI (RFI-) castrated males, RFI- females. At 17 weeks of age, health criteria were evaluated using a gradient scale for increased severity of lameness, body lesions, bursae and tail biting. Individual behavioural activities were recorded by 24-h video tape on the day after health evaluation. The investigative motivation towards unfamiliar objects was quantified at 18 weeks of age. The daily individual feeding patterns were computed from SEF records during the 4 weeks surrounding 12, 17 and 22 weeks of age. All pigs spent significantly most of their time lying in diurnal (80% of total scan) and nocturnal (>89%) periods. The RFI- pigs showed a lower proportion of health problems (P0.34; P

Prader-Willi syndrome (PWS) is a complex disorder that manifests with an array of phenotypes, such as hypotonia and difficulties in feeding during infancy and reduced energy expenditure, hyperphagia, and developmental delays later in life. While the genetic cause has long been known, it is still not clear how mutations at this locus produce this array of phenotypes. In this issue of the JCI, Burnett and colleagues used a comprehensive approach to gain insight into how PWS-associated mutations drive disease. Using neurons derived from PWS patient induced pluripotent stem cells (iPSCs) and mouse models, the authors provide evidence that neuroendocrine PWS-associated phenotypes may be linked to reduced expression of prohormone convertase 1 (PC1). While these compelling results support a critical role for PC1 deficiency in PWS, more work needs to be done to fully understand how and to what extent loss of this prohormone processing enzyme underlies disease manifestations in PWS patients.

This article reports a novel scheme called minimal mean distant scalar leader selection inspired by event driven camera actuation for redundant data minimization. The proposed algorithm aims at actuating minimum number of cameras while maximizing the event area coverage and reducing the resulting traffic overhead. This is accomplished by effective selection of scalar leaders in each sub-region of the monitored region and the chosen scalar leaders operate as informants for event information communication to their respective camera sensors. The less camera actuation with enhanced coverage ratio, minimized redundancy ratio and reduced energy expenditure obtained from the experimentation reveal the effectiveness of the proposed algorithm as compared to three other recent approaches.

While discussion about the benefits and complications of partial foot amputation (PFA) is not new, much of it has hinged on anecdotal evidence and led to the popular view that the risk of complications and secondary amputation is reasonable when weighed against the perceived benefits associated with maintaining the ankle joint and residual foot length, including more normal walking, reduced energy expenditure, and improved quality of life. The research evidence makes it difficult not to question whether these benefits are valid and worth striving to achieve. When you consider that persons who undergo PFA are typically in the later years of their life and have limited mobility, it raises the question of whether we place too much emphasis on achieving the purported functional benefits of PFA and too little emphasis on achieving primary wound healing and mitigating the high rates of complications and subsequent amputation. If further research supports what we see emerging in the evidence, there will be a case to be made for selecting the level of PFA based primarily on the potential for wound healing, rather than trying to strike a balance with the perceived functional benefits. This may mean that transtibial amputation is preferable in many cases, given the lower rates of complications and secondary amputation, very similar function in terms of walking and energy expenditure, and similar lived experience of limb loss when compared with persons with PFA. Further research is needed to better understand the complications and benefits of PFA to make this a more viable, first-and-final amputation procedure.

Restricting energy expenditure is an adaptive response to food shortage. Despite being insulated with massive amount of fat tissues, leptin-deficient mice lose the ability to maintain their body temperature and develop deep hypothermia, which can be suppressed by exogenous leptin, suggesting an important role for leptin in energy expenditure regulation. However, the mechanism underlying the leptin action is not clear. We generated mice with disruption of glutamate release from leptin receptor-expressing neurons by deleting vesicular glutamate transporter 2 in these neurons, and found that these mice developed mild obesity purely due to reduced energy expenditure, exhibited bouts of rapidly reduced energy expenditure, body temperature and locomotion. In addition, these mice exhibited lower energy expenditure and body temperature in response to fasting and were defective in leptin-mediated thermogenic action in brown adipose tissues. Taken together, our results identify a role for glutamate release in mediating leptin action on energy expenditure.

Summary 1. Despite the central importance of the rate of energy expenditure in the lives of animals, the major drivers of within-species variation in energy expenditure remain uncertain, largely because most intraspecific studies focus on one or only a few potential determinants of expenditure. 2. Here, we examine the determinants of daily energy expenditure (DEE) in free-ranging female North American red squirrels (Tamiasciurus hudsonicus Erxleben) occupying a highly seasonal environment. By relating variation in 260 measurements of DEE from 176 individuals to key sources of seasonal (reproductive and foraging stages), environmental (resources and air temperature) and individual (body mass and individual identity) variation, our comprehensive analysis examines the relative importance of DEE predictors that have been more commonly examined in isolation. 3. Red squirrels demonstrated extensive variation in DEE with 5th (177 kJ per day) and 95th (660 kJ per day) percentile DEE levels that would correspond to mammals on an interspecific scale ranging in mass from 148 to 1120 g. 4. Seasonal stage differences accounted for most variation in DEE, with high expenditure during lactation and autumn hoarding, and very low expenditure during winter. Contrary to interspecific studies, energy expenditure increased with increasing ambient temperature and it was weakly related to body mass in all seasons except for winter. High resource availability was associated with reduced energy expenditure in winter, but elevated expenditure during lactation and hoarding. 5. Collectively, these results highlight substantial intraspecific variation in energy expenditure, most of which can be explained by a combination of seasonal stages and environmental conditions, and fundamental differences in the importance and direction of determinants of energy expenditure when examined at the intra- versus the interspecific level.

For many species of fish, size-specific overwinter mortality is an important factor structuring year-class strength. Protracted spawning by bluegill Lepomis macrochirus leads to extreme variation in individual size going into winter that could result in strong, size-specific overwinter mortality, particularly in locations with limited food resources or long, cold winters. We performed laboratory trials to test the effects of winter temperature (4°C or 9°C) and food availability (food present or no food) on the survival of two size-classes (20–30 or 50–60 mm total length) of young-of-year bluegills. Mortality was strongly size selective and appeared to be related to relative condition, suggesting that energy limitation was the primary mechanism of mortality. Fish of both sizes were less active at colder temperatures, leading to increased survival (presumably via reduced energy expenditure). Bluegills fed heavily in food treatments (wet weight/d consumed was typically 2–4% for both large and small ...

Summary Intraspecific agonism is a problem in fish culture. This has corresponding fish welfare implications. As the design of the holding container may moderate aggressive behaviour, the aim of this study was to reduce agonistic behaviour by altering tank dimensions without changing the available volume. The study used swordtails, a popular aquarium species in which dominance hierarchies between males are common. The frequency of attacks initiated by dominant males against subordinate males was significantly reduced in tanks with smaller surface area (t(12) = −3.849, P = 0.002) while the frequency of mating displays, assumed to be a measure of normal behaviour, remained unchanged (t(12) = 1.126, P = 0.282). The time that subordinate males spent feeding was also unaffected (t(12) = −0.081, P = 0.937) while dominant males reduced the time spent feeding in tanks with smaller surface area (t(12) = −3.468, P = 0.005). However, this is unlikely to be detrimental to the health of dominant males but may reflect a decreased food requirement through reduced energy expenditure. Alteration of tank dimensions in this way is therefore a simple means for small-scale facilities and pet stores to reduce agonistic behaviour in swordtails.

The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle substrate levels, glycolytic and oxidative enzymes activity, and membrane transport proteins involved in pH regulation. Instead they appear to be related to a reduced energy expenditure during submaximal exercise and a higher expression of muscle Na(+) ,K(+) pump α-subunits, which via a higher Na(+) ,K(+) pump activity during exercise may delay fatigue development during intense exercise. In conclusion, athletes from disciplines involving periods of intense exercise can benefit from the inclusion of speed endurance sessions in their training programs.

We studied geographical and temporal body size trends among 169 adult museum specimens of the Eurasian otter (Lutra lutra) collected in Sweden between 1962 and 2008, whose sex, year of collection, and locality were known. Skull size and body mass increased significantly in relation to the year of collection, and skull size (but not body mass) was significantly and negatively related to latitude, contrasting Bergmann’s rule and the trend found for Norwegian otters. Latitudinal differences in body size between the two countries may be due to differences in food availability. The temporal increase in body size among Swedish otters resembled that observed for Norway otters, though Swedish otters are smaller with respect to their Norwegian counterparts. Latitude and year represent a combination of environmental factors, including ambient temperature in the year of collection as well as the number of days of ice coverage. We replaced the above factors with mean annual temperature or the number of days of ice coverage, and found that each of these factors explains a similar proportion of the variation in body size as did latitude and year. We hypothesize that this temporal increase in body size is related to a combination of factors, including reduced energy expenditure resulting from increasing ambient temperature, and increased food availability from longer ice-free periods.

Flowers are included in the diets of many primates, but are not generally regarded as making an important contribution to primate energy budgets. However, observations of a number of lemur, platyrrhine, and cercopithecine populations suggest that some flower species may function as key primate fallback foods in periods of low abundance of preferred foods (generally ripe fruits), and that flowers may be preferred foods in some cases. I report heavy reliance on flowers during some study months for a siamang (Symphalangus syndactylus) population in southern Sumatra. Siamangs at Way Canguk spent 12% of feeding time eating flowers from October 2000 to August 2002, and in 1 month flower-feeding time exceeded 40% of total feeding time. The overall availabilities of fig and nonfig fruits, flowers, and new leaves in the study area were not significant predictors of the proportion of time that siamangs spent consuming any plant part. However, flower-feeding time was highest in months when nonfig fruit-feeding time was lowest, and a switch from heavy reliance on fruit to substantial flower consumption was associated with a shift in activity patterns toward reduced energy expenditure, which is consistent with the interpretation that flowers may function as a fallback food for Way Canguk siamangs. Hydnocarpus gracilis, a plant from which siamangs only consume flowers, was the third-most-commonly consumed plant at Way Canguk (after Ficus spp. and Dracontomelon dao), and flowers from this plant were available in most months. It is possible that relatively high local availability of these important siamang plant foods is one factor promoting high siamang density in the study area.

This study aimed to investigate the impact of energy and protein restriction on energy expenditure of gestation (EEgest) in twin-bearing ewes. Multiparous twin-bearing ewes were fed either adequate (A: n = 10) or restricted to 60% of energy and protein requirements (R: n = 10) during the last 6 weeks of gestation. Whole-body energy expenditure (EE) and retained energy (RE) were calculated from respiratory gaseous exchange combined with nitrogen balance at 7, 5 and 2 weeks prepartum. Twin lamb birth weight was lower in the R group compared to those in the A group (7.9 ± 0.31 vs 9.3 ± 0.19 kg, P < 0.01). The EEgest was lower in the R group than the A group (4.6 vs 5.9 MJ/day, SE = 0.30, P < 0.01). Between 5 and 2 weeks prepartum, EEgest contribution to the whole-body EE significantly (P < 0.01) increased from 39% to 45% and from 34% to 40% in the A and R groups, respectively. Based on kg conceptus weight, both EEhomeorhetic (from 292 to 270 kJ/kg/day, SE = 6.2, P < 0.001) and EEconceptus (from 259 to 177 kJ/kg/day, SE = 23.8, P = 0.02) decreased between weeks 5 and 2 prepartum. The EEconceptus tended to be lower (P = 0.06) in the R group than the A group both at 5 weeks (219 vs 298 kJ/kg/day, SE = 32.8) and 2 weeks (from 138 to 217 kJ/kg/day, SE = 30.1) prepartum. In conclusion, energy and protein restriction reduced energy expenditure of gestation calculated per kg conceptus weight. The decrease may be associated with energy expenditure of conceptus growth and maintenance.

Compared with temperate birds, tropical birds have low reproductive rates, slow development as nestlings, and long lifespans. These “slow” life history traits are thought to be associated with reduced energy expenditure, or a slow “pace of life.” To test predictions from this hypothesis, we measured exercise-induced peak metabolic rates (PMR E ) in 45 species of tropical lowland forest birds and compared these data with PMR E for three temperate species. We also compared cold-induced PMR (PMR C ) with PMR E in the same individuals of 19 tropical species. Tropical birds had a 39% lower PMR E than did the temperate species. In tropical birds, PMR C and PMR E scaled similarly with body mass ( M b ), but PMR E was 47% higher than PMR C . PMR E averaged 6.44 × basal metabolic rate (BMR) and PMR C averaged 4.52 × BMR. The slope of the equation relating PMR E to M b exceeded the slope for the equation for BMR vs. M b , whereas slopes for the equations of PMR C and BMR vs. M b did not differ. M b -adjusted residuals of PMR E were positively correlated with residual BMR, whereas residual PMR C and residual BMR were not correlated. PMR E and PMR C were not correlated after we corrected for M b . Temperate birds maintained their body temperature at an 8.6°C lower average air temperature than did tropical species. The lower PMR E values in tropical species suggest that their suite of life history traits on the slow end of the life history continuum are associated with reduced metabolic rates.

The lean body weight phenotype of hepatic lipase (HL)-deficient mice (hl(-/-)) suggests that HL is required for normal weight gain, but the underlying mechanisms are unknown. HL plays a unique role in lipoprotein metabolism performing bridging as well as catalytic functions, either of which could participate in energy homeostasis. To determine if both the catalytic and bridging functions or the catalytic function alone are required for the effect of HL on body weight, we studied (hl(-/-)) mice that transgenically express physiologic levels of human (h)HL (with catalytic and bridging functions) or a catalytically-inactive (ci)HL variant (with bridging function only) in which the catalytic Serine 145 was mutated to Alanine. As expected, HL activity in postheparin plasma was restored to physiologic levels only in hHL-transgenic mice (hl(-/-)hHL). During high-fat diet feeding, hHL-transgenic mice exhibited increased body weight gain and body adiposity relative to hl(-/-)ciHL mice. A similar, albeit less robust effect was observed in female hHL-transgenic relative to hl(-/-)ciHL mice. To delineate the basis for this effect, we determined cumulative food intake and measured energy expenditure using calorimetry. Interestingly, in both genders, food intake was 5-10% higher in hl(-/-)hHL mice relative to hl(-/-)ciHL controls. Similarly, energy expenditure was ~10% lower in HL-transgenic mice after adjusting for differences in total body weight. Our results demonstrate that (1) the catalytic function of HL is required to rescue the lean body weight phenotype of hl(-/-) mice; (2) this effect involves complementary changes in both sides of the energy balance equation; and (3) the bridging function alone is insufficient to rescue the lean phenotype of hl(-/-)ciHL mice.

1. Euthermic Steatomys pratensis showed a circadian rhythm in body temperature ( T b ) ranging 31.1–32.6 °C throughout day and 33.2–35.0 °C at night. 2. Tb of torpid mice was close to ambient temperature ( T a ) in the early hours of the morning, higher in late morning. 3. Daily torpor lasted 5.5 to 11.6 h. 4. Energy expenditure in thermoneutrality was 30.9 kJ day −1 , about three times basal metabolic rate (BMR). 5. For euthermic mice at T a = 20 ° C ADMR averaged 41.4 kJ day −1 but in torpid mice it declined to 18.2 kJ day −1 , an energy saving of 56%. 6. In contrast, huddling at T a = 20 ° C reduced energy expenditure by 18%.

An experiment was conducted to evaluate the effects of feed form on lysine and dietary energy levels necessary for maximum body weight gain (BWG) and feed efficiency (FE) of male broilers from 14 to 30 d and to determine if birds realize a benefit in productive energy from consuming pelleted diets. A 2 x 3 x 2 factoria l treatment arrangement was achieved by feeding diets in two forms (mash and steam- conditioned pellets) with three levels of digestible lysine (0.85, 0.95 and 1.05 % of the diet) and two dietary energy levels (3050 and 3200 kcal ME/kg). Male broiler chicks were provided a nutritionally adequate diet (3100 kcal ME/kg and 22.7% CP) from 0-13 d. Four pens of 32 birds were fed each dietary treatment. Mean body weight and feed consumption were obtained at 14 and 30 d. Average feed intake (AFI) was used to calculate lysine conversion ratio and calories consumed per bird. Pellet-fed birds consumed significantly less digestible lysine (P=0.0061) to achieve the same amount of BWG as the mash-fed birds. Pellet-fed birds exhibited a linear increase in BWG (P=0.0188) with increasing lysine concentrations, while mash-fed birds did not display a growth response at digestible lysine levels greater than 0.85%. Birds fed 3200 kcal ME/kg diets had greater BWG (P=0.006) than those fed 3050 kcal diets. No feed form x dietary energy level interaction was observed for any parameter. Feed form had no effect on AFI (P=0.3784). These findings suggest that improved BWG obtained with pelleted diets may be the result of reduced energy expenditure during meal consumption, indicating that feed form may influence perceived nutrient needs.

The epidemic of obesity has resulted from an imbalance of energy intake and energy expenditure. Further weight gain of individuals and populations can be prevented if energy intake balances energy expenditure. For those who are overweight, reduction in weight can only be achieved by a negative energy balance in which energy expenditure exceeds intake. In this manuscript, we will describe the epidemic of obesity and explore the evidence that reduced energy expenditure accounts for obesity, the role that physical activity plays in weight reduction, and the steps necessary to achieve energy balance within the population.

It is widely believed that torpor is mainly an adaptation of endotherms for cold stress and food limitation. We studied torpor use in the wild by a small tree-roosting microbat from a sub-tropical area during summer when food was abundant. Surprisingly, two torpor bouts per day were employed on each roost-day observed. The first bout occurred in the early morning and the second bout in the late afternoon, whilst a period of normothermia was maintained over the warmest part of the day. Torpor likely reduced energy expenditure substantially, and may be common in small microbats whose day-roosts are poorly insulated, even in sub-tropical climates.

Acta Obstet Gynecol Scand 2002; 81: 603-611. © Acta Obstet Gynecol Scand 2002 Objectives. The effects of menopause transition on metabolic and cardiovascular disease risk in women are unclear. It is unknown whether estrogen deficiency, aging, or a combination of both factors are independent contributors to a worsening health profile in women. We considered the effects of menopause transition and hormone replacement therapy on body composition, regional body fat, energy expenditure, and insulin sensitivity. Methods. A brief review of current literature that has considered the role of menopause transition and hormone replacement therapy on body composition, energy expenditure, and insulin sensitivity with an emphasis on longitudinal investigations. Results. Preliminary evidence suggests that natural menopause is associated with reduced energy expenditure during rest and physical activity, an accelerated loss of fat-free mass, and increased central adiposity and fasting insulin levels. Hormone replacement th...

Bronze Mannikins Lonchura cucullata form flocks of up to 30 birds at the end of the breeding season and huddle in communal nests during winter. Assuming there are thermoregulatory benefits associated with huddling for these small endotherms, particularly during winter, we predicted that dominant individuals in flocks would obtain the central locations within the huddles. We tested this prediction by determining the dominance hierarchies of six captive flocks of five individuals by examining interactions at a feeder. Mannikins were observed to huddle when cold-stressed. Although mannikins do not naturally form linear huddles, for ease of observation we recorded the positions of individually marked birds in linear huddles at 5 °C before and after disturbances every half hour for 3 h. Captive flocks of mannikins established linear dominance hierarchies and dominant individuals obtained the central location within the huddle. The central position in the huddle may be beneficial in thermodynamically challenging environments through reduced energy expenditure.

The design of a building process must consider climat ic variations in the region, the external conditions and the use of available resources in nature, like the sun, vegetation, rain and winds, to provide a built environment with environmental comfort and reduced energy expenditure. But add to urbanization, often with occupancy of disordered ground comes disregarding this knowledge and disregarding local characteristics and as a result reducing the green areas. This disordered occupation associated with the reduction of green spaces is modifying aspects of climate and consequent ly damaging the thermal comfort of users. The objective of this article is to show the use of vegetation in constructive solutions still in project design, presenting the importance of partnership vegetation versus building with a better understanding of the use of vegetation to climate attenuator element. Seeking thereby a healthier

Swimming is a sport that requires considerable training commitment to reach individual performance goals. Nutrition requirements are specific to the macrocycle, microcycle, and individual session. Swimmers should ensure suitable energy availability to support training while maintaining long term health. Carbohydrate intake, both over the day and in relation to a workout, should be manipulated (3–10g/kg of body mass/day) according to the fuel demands of training and the varying importance of undertaking these sessions with high carbohydrate availability. Swimmers should aim to consume 0.3g of high-biological-value protein per kilogram of body mass immediately after key sessions and at regular intervals throughout the day to promote tissue adaptation. A mixed diet consisting of a variety of nutrient-dense food choices should be sufficient to meet the micronutrient requirements of most swimmers. Specific dietary supplements may prove beneficial to swimmers in unique situations, but should be tried only with the support of trained professionals. All swimmers, particularly adolescent and youth swimmers, are encouraged to focus on a well-planned diet to maximize training performance, which ensures sufficient energy availability especially during periods of growth and development. Swimmers are encouraged to avoid rapid weight fluctuations; rather, optimal body composition should be achieved over longer periods by modest dietary modifications that improve their food choices. During periods of reduced energy expenditure (taper, injury, off season) swimmers are encouraged to match energy intake to requirement. Swimmers undertaking demanding competition programs should ensure suitable recovery practices are used to maintain adequate glycogen stores over the entirety of the competition period.