Evidence is growing that the individual adjustment of energy targets guided by indirect calorimetry (IC) can improve outcome. With the development of a new generation of devices that are easier to use and rapid, it appears important to share knowledge and expertise that may be used to individualize nutrition care. Despite the focus of this tutorial being on one contemporary device, the principles of IC apply across existing devices and can assist tailoring the nutrition prescription and in assessing response to nutrition therapy. The present tutorial addresses its clinical application in intubated mechanically ventilated and spontaneously breathing adult patients (canopy), i.e. it covers the range from critical illness to outpatients. The cases that are presented show how the measured energy expenditure (mEE), and the respiratory quotient (RQ), i.e. the ratio of expired CO2 to consumed O2, should be applied in different cases, to adapt and individualize nutrition prescription, as it is a good marker of over- or underfeeding at the different stages of disease. The RQ also informs about the patient\'s body\'s capacity to use different substrates: the variations of RQ indicating the metabolic changes revealing insufficient or excessive feeding. The different cases reflect the use of a new generation device as a metabolic monitor that should be combined with other clinical observations and laboratory biomarkers. The tutorial also points to some shortcomings of the method, proposing alternatives.

Intermittent fasting (IF) approach to weight loss obviates the inconvenience of calorie counting required in daily caloric restriction (DCR). A metabolic defense mechanism (MDM) obstructs weight loss and facilitates weight regain possibly by increasing hunger and efficiency of exercise energy expenditure (EEf), and by reducing resting metabolic rate (RMR) and energy expenditure (EE) including physical activity (PA). IF may test whether its paradigm can better counteract MDM than DCR. A knowledge gap exists about whether the duration of weekly uninterrupted fasts (UFs), when the IF protocols are isocaloric, affects the MDM. The aim and objective of this 82-week study were to determine whether 36 hours of near-absolute twice-weekly UF will exacerbate MDM but generate similar rates of weight and fat losses compared to four IF studies featuring 20 hours of weekly UF with both IF protocols matched for weekly hours of fast (108) and free access to food (60), a fasting-to-eating (F/E) ratio of 1.8. This case report presents results of twice-weekly fasting on non-consecutive days (5:2-NC) and compares them to results from a 4:3-NC protocol with a 20-hour UF caused by a modification of providing a 500-600 kcal meal on three fasting days (M4:3-NC). Because the large meal raises insulin concentration for four hours at the start of the fasting day, the 20-hour UF consists of the remaining eight hours on the fasting day, followed by 12 additional nocturnal hours of fasting. The hypotheses were that (1) because of their matched F/E ratio, the rates of weight and fat losses will be similar in both protocols, and (2) because of its longer UF period, hunger will be higher and RMR and EE will be lower, in 5:2-NC than in M4:3-NC protocol. The main findings were that the 5:2-NC protocol produced (1) slower rates of weight and fat losses, (2) modest reduction in the sensation of hunger and substantial decline in fullness, (3) no change in RMR and EE, and (4) fourfold post-fast increase in the circulating concentration of the ketone body ß-hydroxybutyrate (BHB), 2.5 greater than in the M4:3-NC protocol. The absence of increased hunger and changes in EE, the variability of the rate of weight loss in the 5:2-NC protocol, plus increased EEf in one M4:3-NC study, suggest that IF does not mitigate MDM, but that shortened UF period in M4:3-NC reduces the rise in BHB. Thus, the addition of a large meal on fasting days is unnecessary for the prevention of hunger and is counterproductive for increases in BHB and its potential health benefits. Continuous practice of the 5:2-NC protocol allows sustained weight loss and maintenance of lost weight with diminished hunger for as long as it is implemented.

Intermittent fasting (IF) approach for weight loss obviates the inconvenience of calorie counting of daily caloric restriction (DCR). It tests IF ability to better counteract a metabolic defense mechanism (MDM) than DCR. MDM obstructs weight loss and facilitates weight regain possibly by increasing hunger and efficiency of exercise energy expenditure (EEf), and by reducing resting metabolic rate (RMR) and physical activity (PA). A knowledge gap exists about whether the duration of weekly uninterrupted fasts (UFs), where the IF protocols are isocaloric, mitigate the MDM. This study compares two IF protocols that have the same weekly number of hours of fast (108) and free access to food (60), but which differ in the duration of UF. An 82-week case report was conducted with twice-weekly near-absolute 36-hour fasts on non-consecutive days (5:2-NC) and compared to ten studies with a 20-hour UF on three non-consecutive days (4:3-NC) modified through provision of a 500-600 kcal meal on fasting days. The large meal raised insulin concentration for 4 hours and reduced the UF to 8 hours followed by 12 nocturnal hours of fasting. The hypotheses were that (1) because of their matched F/E ratio, the rates of weight and fat losses will be similar in both protocols, and (2) because of its longer UF period, hunger will be higher and RMR and voluntary physical activity lower, in 5:8-NC than in M4:3-NC protocol,. The main differences between the two protocols were, (1) slower rates of weight and fat losses, (2) lower sensation of hunger and substantial decline in fullness, no change in RMR and physical activity, and 2.5 times higher post-fast concentration of the ketone body beta-hydroxybutyrate (BHB) in 8:2-NC compared to M4:3-NC protocol. Absence of increased hunger and the variability of the rate of weight loss in 5:2-NC protocol, plus increased EEf in one M4:3-NC study suggest that IF does not curtail MDM, but shortened UF period in M4:3-NC reduces elicitation of BHB. Thus, the addition of a large meal on fasting days is unnecessary for prevention of hunger and is counterproductive for increases in BHB and its potential health benefits.

Physical activity is known to convey protection against several cancers. However, results on the risk of lymphoma overall and its subtypes have been inconsistent. The aim of this study was to investigate occupational and recreational physical activity in relation to risk of lymphoma subtypes adjusting for established occupational risk factors. We applied standardized tools to assess energy expenditure at work and in recreational physical activities to the questionnaire information on lifetime work and exercise history in 1117 lymphoma cases, including Hodgkin lymphoma, and B-cell (including chronic lymphocytic leukemia, and multiple myeloma) and T-cell non-Hodgkin\'s lymphoma (NHL) subtypes, and 1207 controls who took part in the multicentre European EpiLymph case-control study. We calculated the risk of lymphoma (all subtypes), B-cell NHL and its most represented subtypes, and Hodgkin\'s lymphoma (all subtypes) associated with weekly average Metabolic Equivalent of Task (MET-hours/week) and cumulative MET-hours of lifetime recreational, occupational, and total physical activity, with unconditional logistic regression and polytomous regression analysis adjusting by age, centre, sex, education, body mass index, history of farm work and solvent use. We observed an inverse association of occupational, and total physical activity with risk of lymphoma (all subtypes), and B-cell non-Hodgkin\'s lymphoma among women, and an upward trend in risk of Hodgkin\'s lymphoma with recreational and total physical activity among men, for which we cannot exclude chance or bias. Our results suggest no effect of overall physical activity on risk of lymphoma and its subtypes.

Paediatric obstructive sleep disordered breathing (OSDB) has a considerable impact on cardiovascular physiology, but the consequences on children\'s basal metabolism and response to exercise are far from being known. The objective was to propose model estimations for paediatric OSDB metabolism at rest and during exercise. A retrospective case-control analysis of data from children submitted to otorhinolaryngology surgery was performed. The heart rate (HR) was measured, while oxygen consumption (VO2) and energy expenditure (EE) at rest and during exercise were obtained using predictive equations. The results for the patients with OSDB were compared with controls. A total of 1256 children were included. A total of 449 (35.7%) had OSDB. The patients with OSDB showed a significantly higher resting heart rate (94.55 ± 15.061 bpm in OSDB vs. 92.41 ± 15.332 bpm in no-OSDB, p = 0.041). The children with OSDB showed a higher VO2 at rest (13.49 ± 6.02 mL min-1kg-1 in OSDB vs. 11.55 ± 6.83 mL min-1kg-1 in no-OSDB, p = 0.004) and a higher EE at rest (67.5 ± 30.10 cal min-1kg-1 in OSDB vs. 57.8 + 34.15 cal min-1kg-1 in no-OSDB, p = 0.004). At maximal exercise, patients with OSDB showed a lower VO2max (33.25 ± 5.82 mL min-1kg-1 in OSDB vs. 34.28 ± 6.71 in no-OSDB, p = 0.008) and a lower EE (166.3 ± 29.11 cal min-1kg-1 in OSDB vs. 171.4 ± 33.53 cal min-1kg-1 in no-OSDB, p = 0.008). The VO2/EE increment with exercise (Δ VO2 and Δ EE) was lower in OSDB for all exercise intensities (p = 0.009). This model unveils the effect of paediatric OSDB on resting and exercise metabolism. Our findings support the higher basal metabolic rates, poorer fitness performance, and cardiovascular impairment found in children with OSDB.

A traumatic brain injury (TBI) is one of the most common pediatric traumas among children in the United States. Appropriate nutrition support, including the initiation of early enteral nutrition, within the first 48 h after injury is crucial for children with a TBI. It is important that clinicians avoid both underfeeding and overfeeding, as both can lead to poor outcomes. However, the variable metabolic response to a TBI can make determining appropriate nutrition support difficult. Because of the dynamic metabolic demand, indirect calorimetry (IC) is recommended, instead of predictive equations, to measure energy requirements. Although IC is suggested and ideal, few hospitals have the technology available. This case review discusses the variable metabolic response, identified using IC, in a child with a severe TBI. The case report highlights the ability of the team to meet measured energy requirements early, even in the setting of fluid overload. It also highlights the presumed positive impact of early and appropriate nutrition provision on the patient\'s clinical and functional recovery. Further research is needed to investigate the metabolic response to TBIs in children and the impact optimal feedings based on the measured resting energy expenditure have on clinical, functional, and rehabilitation outcomes.

UNASSIGNED: The aim of this case report was to describe the sleep responses in a male combat sport athlete, who was engaging in both chronic (CWL) and acute (AWL) weight loss practices in order to reduce body mass for a national competition.
UNASSIGNED: During the first seven weeks of training (Phases 1 and 2), the athlete adhered to a daily energy intake (EI) equating to their resting metabolic rate (1700 kcal·day-1) followed by a reduction in EI (915-300 kcal·day-1) in the 5 days before weighing in (Phase 3). Nocturnal sleep was monitored throughout the 8-week training period using wristwatch actigraphy and frequent measurements of body mass/composition, daily exercise energy expenditure and training load (TL) were taken.
UNASSIGNED: The athlete was in a state of low energy availability (LEA) during the entire training period. There was a very large decrease in LEA status during phase 3 compared with phases 1 and 2 (3 vs. 20 kcal·kgFFM·day-1) and there was a small decrease in TL during phase 3 compared with phase 2 (410 vs. 523 AU). The athlete\'s sleep efficiency increased throughout the training period, but total sleep time displayed a small to moderate decrease in phase 3 compared with phases 1 and 2 (386 vs. 429 and 430 min). However, correlational analysis demonstrated trivial to small, non-significant relationships between sleep characteristics and the athlete\'s LEA status and TL.
UNASSIGNED: These findings suggest that CWL and AWL practices that cause fluctuations in LEA and TL may be implemented without compromising the sleep of combat sport athletes.

OBJECTIVE: Low resting metabolic rate (RMR), as a risk factor for weight gain and obesity, can be influenced by many factors. Empirical research has confirmed the role of appetite and related hormones in obesity and energy intake. This study aimed to investigate the relationship between appetite and related hormones in overweight or obese Iranian women with normal and hypo RMR.
METHODS: This case-control study was conducted on 42 Iranian adult women (21 cases, and 21 controls), aged 18-48 years. An impedance body analyzer was used to obtain the body composition and an indirect calorimeter was used to assess the RMR. The Flint questionnaire was used to assess appetite, dietary intake, and physical activity were assessed by FFQ and IPAQ questionnaires respectively, and ELISA kits were used to assess leptin, ghrelin, and insulin hormones.
RESULTS: The results of the study demonstrated a negative association between ghrelin hormone level (β = -0.34, 95%CI = -61.70,-3.86, P-value = 0.027) and RMR, and a positive association between insulin hormone level (β = 0.48, 95%CI = 9.38-34.35, P-value = 0.001) and RMR. Also, results of the appetite questionnaire showed that, in general, both appetite (β = 0.32, 95%CI = -0.10-2.99 P-value = 0.044) and hunger variable (β = 0.30, 95%CI = 0.04-5.87, P-value = 0.047) have a positive association with RMR. There was no significant association between leptin levels and RMR.
CONCLUSIONS: It is evident that appetite and related hormones have a potential role in promoting a normal RMR.

Restoration of functional mobility including gait and balance are fundamental to prosthetic rehabilitation in children with rotationplasty. The literature to characterize and investigate the correlation between postural balance and gait following rotationplasty are scarce. This study examines the characteristics of balance and prosthetic gait in a subject with rotationplasty and checks whether any association exists between them.
A 14-year-old boy with rotationplasty following Ewing\'s sarcoma was fitted with a custom made prosthesis. Center of pressure (COP) measures using the HUMAC® Balance & Tilt System (CSMi, Stoughton, MA), temporal-spatial gait parameters, and energy expenditure measured by a 10 meter walk test were recorded using the new and old prosthesis. A control subject was used for comparison.
The stability score, path length, and average velocity of COP improved in a new prosthesis for both standing conditions. Gait parameters were improved and energy expenditure was marginally reduced with the new prosthesis. However, overall prosthetic gait was significantly different compared to the control subject.
This subject-centric approach successfully improved balance, gait parameters, and energy expenditure by providing better alignment, fit, and comfort with a custom prosthesis.

Our studies in primary human adipocytes show that naringenin, a citrus flavonoid, increases oxygen consumption rate and gene expression of uncoupling protein 1 (UCP1), glucose transporter type 4, and carnitine palmitoyltransferase 1β (CPT1β). We investigated the safety of naringenin, its effects on metabolic rate, and blood glucose and insulin responses in a single female subject with diabetes. The subject ingested 150 mg naringenin from an extract of whole oranges standardized to 28% naringenin three times/day for 8 weeks, and maintained her usual food intake. Body weight, resting metabolic rate, respiratory quotient, and blood chemistry panel including glucose, insulin, and safety markers were measured at baseline and after 8 weeks. Adverse events were evaluated every 2 weeks. We also examined the involvement of peroxisome proliferator-activated receptor α (PPARα), peroxisome proliferator-activated receptor γ (PPARγ), protein kinase A (PKA), and protein kinase G (PKG) in the response of human adipocytes to naringenin treatment. Compared to baseline, the body weight decreased by 2.3 kg. The metabolic rate peaked at 3.5% above baseline at 1 h, but there was no change in the respiratory quotient. Compared to baseline, insulin decreased by 18%, but the change in glucose was not clinically significant. Other blood safety markers were within their reference ranges, and there were no adverse events. UCP1 and CPT1β mRNA expression was reduced by inhibitors of PPARα and PPARγ, but there was no effect of PKA or PKG inhibition. We conclude that naringenin supplementation is safe in humans, reduces body weight and insulin resistance, and increases metabolic rate by PPARα and PPARγ activation. The effects of naringenin on energy expenditure and insulin sensitivity warrant investigation in a randomized controlled clinical trial.