Weight loss does not affect the sit-to-stand metabolic cost in adolescents with obesity.

PURPOSE: There is considerable interest in simple and effective methods to reduce sitting time and increase energy expenditure, and standing breaks have emerged as a realisable approach in individuals with obesity. The aim of the present study was to determine the extent to which energy expenditure in standing differs from sitting, and whether this energetic and metabolic-related responses are modified following a weight loss program in adolescents with obesity. METHODS: After body composition assessment (DXA), cardiorespiratory and metabolic variables were continuously recorded (indirect calorimetry) during 10 min while sitting and then during 5 min standing posture before (n = 21; T1) and at the end of a multidisciplinary intervention (n = 17; T2) in adolescents with obesity. RESULTS: Before and after the intervention, energy expenditure and fat oxidation rates were significantly increased in standing compared with sitting. Weight loss did not change the relationship between sitting and standing energy expenditure. Sitting energy expenditure represented 1.0 and 1.1 Metabolic Equivalent of Task at T1 and T2, and increased to 1.1 and 1.2 during standing at T1 and T2, respectively. The percentage of change of android fat mass between T1 and T2 was positively associated with the percentage of change in energy expenditure from sitting to standing at T2. CONCLUSION: The vast majority of the adolescents with obesity significantly increased their energy expenditure between sitting and standing, both before and after a weight loss intervention. However, the standing posture did not allow breaking the sedentary threshold. Abdominal fat mass is associated with energic profile.

Guidance for assessment of the muscle mass phenotypic criterion for the Global Leadership Initiative on Malnutrition (GLIM) diagnosis of malnutrition.

The Global Leadership Initiative on Malnutrition (GLIM) provides consensus criteria for the diagnosis of malnutrition that can be widely applied. The GLIM approach is based on the assessment of three phenotypic (weight loss, low body mass index, and low skeletal muscle mass) and two etiologic (low food intake and presence of disease with systemic inflammation) criteria, with diagnosis confirmed by any combination of one phenotypic and one etiologic criterion fulfilled. Assessment of muscle mass is less commonly performed than other phenotypic malnutrition criteria, and its interpretation may be less straightforward, particularly in settings that lack access to skilled clinical nutrition practitioners and/or to body composition methodologies. In order to promote the widespread assessment of skeletal muscle mass as an integral part of the GLIM diagnosis of malnutrition, the GLIM consortium appointed a working group to provide consensus-based guidance on assessment of skeletal muscle mass. When such methods and skills are available, quantitative assessment of muscle mass should be measured or estimated using dual-energy x-ray absorptiometry, computerized tomography, or bioelectrical impedance analysis. For settings where these resources are not available, then the use of anthropometric measures and physical examination are also endorsed. Validated ethnic- and sex-specific cutoff values for each measurement and tool are recommended when available. Measurement of skeletal muscle function is not advised as surrogate measurement of muscle mass. However, once malnutrition is diagnosed, skeletal muscle function should be investigated as a relevant component of sarcopenia and for complete nutrition assessment of persons with malnutrition.

Guidance for assessment of the muscle mass phenotypic criterion for the Global Leadership Initiative on Malnutrition diagnosis of malnutrition.

The Global Leadership Initiative on Malnutrition (GLIM) provides consensus criteria for the diagnosis of malnutrition that can be widely applied. The GLIM approach is based on the assessment of three phenotypic (weight loss, low body mass index, and low skeletal muscle mass) and two etiologic (low food intake and presence of disease with systemic inflammation) criteria, with diagnosis confirmed by any combination of one phenotypic and one etiologic criterion fulfilled. Assessment of muscle mass is less commonly performed than other phenotypic malnutrition criteria, and its interpretation may be less straightforward, particularly in settings that lack access to skilled clinical nutrition practitioners and/or to body composition methodologies. In order to promote the widespread assessment of skeletal muscle mass as an integral part of the GLIM diagnosis of malnutrition, the GLIM consortium appointed a working group to provide consensus-based guidance on assessment of skeletal muscle mass. When such methods and skills are available, quantitative assessment of muscle mass should be measured or estimated using dual-energy x-ray absorptiometry, computerized tomography, or bioelectrical impedance analysis. For settings where these resources are not available, then the use of anthropometric measures and physical examination are also endorsed. Validated ethnic- and sex-specific cutoff values for each measurement and tool are recommended when available. Measurement of skeletal muscle function is not advised as surrogate measurement of muscle mass. However, once malnutrition is diagnosed, skeletal muscle function should be investigated as a relevant component of sarcopenia and for complete nutrition assessment of persons with malnutrition.

The role of CT-scan assessment of muscle mass in predicting postoperative surgical complications after renal transplantation.

PURPOSE: Despite a high rate of undernutrition in renal transplantation recipients, prognostic value of sarcopenia remains unclear. We evaluated the relation between sarcopenia and post-operative outcomes after renal transplantation. METHODS: During 7 years, each patient who underwent renal transplantation was retrospectively included. Patients with no recent pre-operative CT-scan were excluded. Sarcopenia was evaluated by measuring the muscle surface area on CT-scan section passing through the third lumbar vertebra. Main outcomes were post-operative complications at 1 month and 1 year according to the Clavien-Dindo classification. RESULTS: Overall, 102 patients were included. One month of complication rate was 63.9%. At 1 year, 60.8% experienced at least one medical complication and 29.4% one surgical complication. At 1 year post transplantation, low muscle density on CT scan was a surgical complication risk factor (OR = 0.6, 95% CI = [0.3-0.9], p = 0.05). The area under the curve of a 1-year complication predictive model including muscle density was 0.64. We did not observe significant relationship between CT-scan sarcopenia indicator and 1-month post-transplantation complication. CONCLUSION: Although no clear link between sarcopenia and complications was exhibited in our study, low CT-scan muscle density was associated with 1-year surgical complications. The role of muscle density and its relation with sarcopenia and post-transplantation outcomes should be further explored.

Assessment of Intramuscular Fat and Correlation with Body Composition in Patients with Rheumatoid Arthritis and Spondyloarthritis: A Pilot Study.

Rheumatoid arthritis (RA) and spondyloarthritis (SpA) are associated with changes in body composition. Ectopic intramuscular fat (IMAT) may alter muscle function and contribute to cardiometabolic disorders. In a pilot study, we analyzed IMAT in the calf with peripheral quantitative computed tomography (pQCT) and examined correlations between IMAT quantity and body composition parameters. In 20 patients with active RA and 23 with active SpA, IMAT was correlated with visceral fat (VAT; r = 0.5143 and 0.6314, respectively; p < 0.05) and total lean mass (r = 0.5414 and 0.8132, respectively; p < 0.05), but not with whole body fat mass. Total lean mass mediated 16% and 33% of the effects of VAT on IMAT in RA and SpA, respectively. In both RA and SpA, calf muscle area was correlated with total lean mass (r = 0.5940 and r = 0.8597, respectively; p < 0.05) and fat area was correlated with total body fat (r = 0.6767 and 0.5089, respectively; p < 0.05) and subcutaneous fat (r = 0.6526 and 0.5524, respectively; p < 0.05). Fat area was inversely correlated with handgrip and walking tests, and it was associated with disease activity and disability. We showed that ectopic IMAT, measured with pQCT, was correlated with VAT, but not with total body fat, in RA and SpA. This result suggests that metabolically active fat was specifically associated with IMAT.

Energy cost of walking and body composition changes during a 9-month multidisciplinary weight reduction program and 4-month follow-up in adolescents with obesity.

The purpose of the present study was to investigate changes in the energy cost of locomotion during walking (Cw) related to changes in body mass (BM, kg) and body composition in adolescents with obesity. Twenty-six (12 boys and 14 girls) obese adolescents (mean: body mass index, 33.6 ± 3.7 kg·m-2; 42.7 ± 4.5% fat mass (FM)) followed a 9-month multidisciplinary inpatient weight-reduction program consisting of lifestyle education, moderate energy restriction, and regular physical activity in a specialised institution. At baseline (M0), the end of the 9-month program (M9), and after the 4-month follow-up (M13), oxygen consumption and carbon dioxide production of the standardised activity program were assessed by whole-body indirect calorimetry over 24 hours, and body composition was assessed by dual-energy X-ray absorptiometry. At M9, adolescents showed an 18% reduction in BM (p < 0.001) and 40% in total FM, while fat-free mass (kg) remained stable in boys but decreased by ∼6% in girls (p = 0.001). Similarly, the mean Cw decreased by 20% (p < 0.001). At M13, BM, FM, and Cw were slightly higher compared with at M9. In conclusion, moderate energy restriction and regular moderate physical activities improved walking economy, improved exercise tolerance, and induced beneficial changes in the body composition of adolescents with obesity. Novelty: Reduction of FM in the trunk region, and consequently reducing the work carried out by respiratory muscles, contributes to reducing Cw in adolescents with obesity. A lower walking cost can be effective in improving exercise tolerance and quality of life in obese adolescents.

Day and night changes in energy expenditure of patients on automated peritoneal dialysis.

RATIONALE: Automated peritoneal dialysis (APD) treatment for end-stage kidney disease affords patients a degree of autonomy in everyday life. Clinical investigations of their energy expenditure (EE) are usually based on resting EE, which could mask day and night variations in EE. The aim of this study, therefore, was to compare the components of EE in APD patients and healthy control (C) subjects. MATERIAL AND METHOD: Patients treated with APD for more than 3 months were compared with C volunteers matched for age and lean body mass (LBM). Biochemical analyses were performed and body composition was determined by DEXA to adjust EE to LBM. Total EE, its different components and respiratory quotients (RQ) were measured by a gas exchange method in calorimetric chambers. Spontaneous total and activity-related EE (AEE) were also measured in free-living conditions over 4 days by a calibrated accelerometer and a heart rate monitor. RESULTS: APD (n = 7) and C (n = 7) patients did not differ in age and body composition. REE did not differ between the two groups. However, prandial increase in EE adjusted for dietary energy intake was higher in APD patients (+57.5 ± 12.71 kcal/h) than in C subjects (+33.8 ± 10.5 kcal/h, p = 0.003) and nocturnal decrease in EE tended to be lower in APD patients undergoing dialysis sessions (- 4.53 ± 8.37 kcal/h) than in subjects (- 11.8 ± 7.69 kcal/h, p = 0.059). Resting RQ (0.91 ± 0.09 vs 0.81 ± 0.04, p = 0.032) and nocturnal RQ (0.91 ± 0.09 vs 0.81 ± 0.04, p = 0.032) were significantly higher in APD patients, indicating a preferential use of glucose substrate potentially absorbed across the peritoneum. AEE was lower in APD patients (595.9 ± 383.2 kcal/d) than in C subjects (1205.2 ± 370.5 kcal/d, p = 0.011). In contrast, energy intakes were not significantly different (1986 ± 465 vs 2083 ± 377 kcal/d, p = 0.677). CONCLUSION: Although the two groups had identical resting EE, APD patients had a higher prandial increase in EE, a lower activity-related EE and higher resting and nocturnal RQ than healthy subjects.

Increased resting energy expenditure compared with predictive theoretical equations in amyotrophic lateral sclerosis.

OBJECTIVES: Approximately 50% to 60% of amyotrophic lateral sclerosis (ALS) is characterized by an increase in metabolic rate. The Harris and Benedict (HB) 1919 formula is the equation mainly used to calculate resting energy expenditure (cREE) compared with measured REE (mREE) by indirect calorimetry (IC), but other formulas are also applied in current practice. The present study aimed to assess mREE in patients with ALS compared with 12 cREE formulas and study the relevant threshold of REE variation to screen patients with a higher evolving risk. METHODS: Nutritional assessments and body composition (by bioimpedance analysis) were performed in patients with ALS. mREE was measured by IC, and cREE was calculated using the HB 1919, HB 1984, World Schofield, De Lorenzo, Johnstone, Mifflin, World Health Organization/Food and Agriculture Organization, Owen, Fleisch, Wang, Rosenbaum, and Nelson formulas. Functional and respiratory evolution and survival by log-rank test according to two thresholds of REE variation (10% and 20%) were studied. RESULTS: A total of 315 patients with ALS were included in the study. The median mREE was 1503 kcal/24 h (range, 1290-1698 kcal/24 h), which was higher than all predictive equations (P < 0.0001). Depending on the predictive equation, REE variation >10% and 20% was found in 35.2% to 76.3% and 14.6% to 53.3% of patients with ALS, respectively. Patients with an REE variation >20% with HB 1919 and HB 1984 had a lower survival. Moreover, with this same threshold and the Mifflin formula, patients had higher functional and respiratory evolutions and lower survival. CONCLUSIONS: The increase in metabolic rate is present according to the different cREE formulas used compared with IC. In clinical practice, REE formulas (e.g., HB 1919, HB 1984, or Mifflin) can be used as a reference value compared with IC to screen patients with ALS with an REE variation >20% and a higher evolving risk.

Is the SPARTACUS 15-15 test an accurate proxy for the assessment and tracking of maximal aerobic capacities in adolescents with obesity?

[Purpose] While there is a need for reliable field tests for the evaluation of physical fitness in pediatric obesity, the present work i) evaluates the validity of the Spartacus 15-15 test in indirectly assessing maximal aerobic capacity in adolescents with obesity and ii) evaluates its sensibility to weight loss. [Participants and Methods] Fifty-five 11-16 year-old adolescents with obesity (Tanner 3-4) were enrolled in a 12-week weight-management intervention. Maximal Aerobic fitness (VO2peak test + Spartacus test) and body composition (Dual X-ray absorptiometry) were assessed at baseline and after 12 weeks. [Results] Moderate correlations were found at baseline between VO2peak (2,231.90 ± 465.6 mL/min) and Spartacus stage (6.83 ± 1.8 stage, r=0.52; p≤0.05), speed (12.85 ± 1.8 km/h, r=0.52 ; p≤0.05) and time (20.6 ± 5.4 min; r=0.50; p≤0.05). The intervention favored significant improvements for VO2peak, Spartacus Rate of Perceived Exertion final stage, maximal speed and time. Change over time in VO2peak and Spartacus variables were not correlated. [Conclusion] The Spartacus test can be used as a proxy for VO2peak at baseline and can be used to estimate VO2peak using the proposed equation. The Spartacus 15-15 test might be a better indicator for changes in functional capacity than an indicator of VO2peak changes in youth with obesity.

Assessment of Malnutrition, Sarcopenia and Frailty in Patients with Cirrhosis: Which Tools Should We Use in Clinical Practice?

Malnutrition is a common comorbidity in patients with cirrhosis. Its prognostic value is indisputable as it greatly affects the evolution of liver diseases. It has a major impact on both morbi-mortality before and after liver transplantation. Being now integrated in the definition of malnutrition and recognized as a new entity in the international classification of diseases, physicians have taken great interest in sarcopenia. Its negative consequences on the fate of patients with cirrhosis are well-demonstrated. The concept of frailty has recently been enlarged to chronic liver diseases as symptoms of impaired global physical functioning. In this article, we will discuss the definitions of malnutrition and emphasize its links with sarcopenia and frailty. We will show the relevance of frailty and sarcopenia in the course of liver diseases. The emerging role of muscle depletion on the cardiorespiratory system will also be highlighted. The importance of body composition will be demonstrated and the main tools reviewed. Finally, we adapted the definition of malnutrition to patients with cirrhosis based on the assessment of sarcopenia together with reduced food intakes.

Sarcopenia: revised European consensus on definition and diagnosis.

Background: in 2010, the European Working Group on Sarcopenia in Older People (EWGSOP) published a sarcopenia definition that aimed to foster advances in identifying and caring for people with sarcopenia. In early 2018, the Working Group met again (EWGSOP2) to update the original definition in order to reflect scientific and clinical evidence that has built over the last decade. This paper presents our updated findings. Objectives: to increase consistency of research design, clinical diagnoses and ultimately, care for people with sarcopenia. Recommendations: sarcopenia is a muscle disease (muscle failure) rooted in adverse muscle changes that accrue across a lifetime; sarcopenia is common among adults of older age but can also occur earlier in life. In this updated consensus paper on sarcopenia, EWGSOP2: (1) focuses on low muscle strength as a key characteristic of sarcopenia, uses detection of low muscle quantity and quality to confirm the sarcopenia diagnosis, and identifies poor physical performance as indicative of severe sarcopenia; (2) updates the clinical algorithm that can be used for sarcopenia case-finding, diagnosis and confirmation, and severity determination and (3) provides clear cut-off points for measurements of variables that identify and characterise sarcopenia. Conclusions: EWGSOP2's updated recommendations aim to increase awareness of sarcopenia and its risk. With these new recommendations, EWGSOP2 calls for healthcare professionals who treat patients at risk for sarcopenia to take actions that will promote early detection and treatment. We also encourage more research in the field of sarcopenia in order to prevent or delay adverse health outcomes that incur a heavy burden for patients and healthcare systems.

Which Assessment Method of Malnutrition in Head and Neck Cancer?

Objective To assess the value of several diagnostic methods of nutritional status during the initial management of a head and neck cancer. Study Design Single-center prospective study. Setting Tertiary referral center. Subjects and Methods Ninety patients with head and neck cancer participated in the study. Assessment of their nutritional status was made with anthropometric, biological, body, and muscle measurements (the last by computed tomography: L3 muscle mass index [L3MMI]). Assessment of muscle performance (functional reflection of nutritional status) was made via the Short Physical Performance Battery test. The malnutrition thresholds were set according to the literature. Results Mean body mass index (BMI) was 24.6 ± 5.4 kg/m2. Mean weight loss and albumin levels were -4.5 ± 10.5 kg and 37.1 ± 5.2 g/L, respectively. Fourteen percent of patients were diagnosed as malnourished on the basis of BMI, 54% according to the Nutritional Risk Index (NRI), and 58% by L3MMI. There was 64% agreement between NRI and L3MMI ( P < .001). All patients identified as malnourished by BMI were considered as such by the other assessment methods; however, many malnourished patients had normal or high BMI. The Short Physical Performance Battery score was low particularly among patients considered to be the most undernourished by the other methods. Conclusion NRI and L3MMI are the best methods to identify patients as being malnourished. Functional muscle assessment can determine the severity of malnutrition.

A Novel Smartphone Accelerometer Application for Low-Intensity Activity and Energy Expenditure Estimations in Overweight and Obese Adults.

Physical inactivity and sedentary behaviors are on the rise worldwide and contribute to the current overweight and obesity scourge. The loss of healthy life style benchmarks and the lack of the need to move make it necessary to provide feedback about physical and sedentary activities in order to promote active ways of life. The aim of this study was to develop a specific function adapted to overweight and obese people to identify four physical activity (PA) categories and to estimate the associated total energy expenditure (TEE). This function used accelerometry data collected from a smartphone to evaluate activity intensity and length, and TEE. The performance of the proposed function was estimated according to two references (Armband® and FitmatePro®) under controlled conditions (CC) for a 1.5-h scenario, and to the Armband® device in free-living conditions (FLC) over a 12-h monitoring period. The experiments were carried out with overweight and obese volunteers: 13 in CC and 27 in FLC. The evaluation differences in time spent in each category were lower than 7% in CC and 6% in FLC, in comparison to the Armband® and FitmatePro® references. The TEE mean gap in absolute value between the function and the two references was 9.3% and 11.5% in CC, and 8.5% according to Armband® in FLC.

Plasma fatty acid biomarkers are associated with gait speed in community-dwelling older adults: The Three-City-Bordeaux study.

BACKGROUND & AIMS: Nutritional factors, such as fatty acids (FA), could modulate physical performance in the elderly. In particular, the opposite properties of long-chain n-3 and n-6 polyunsaturated FAs (LC PUFAs) could impact muscle function. We aimed to assess the cross-sectional association between plasma FAs and gait speed in French elderly community-dwellers. METHODS: Elderly participants from the Bordeaux centre of the Three-City Study were included. The proportion of 12 FAs, and gait speed (m/s) were measured concomitantly at enrollment. Low gait speed (LGS) was defined as below the first quartile of gait speed. FA patterns were derived from the 12 individual FAs using principal component analysis. Multivariate logistic regression models were used and odds-ratios (OR) were expressed per one additional standard-deviation unit of each plasma FA or per one additional unit of pattern score. RESULTS: Among 982 participants, 239 (24.3%) had a low gait speed (<0.63 m/s) at baseline. Regarding individually each FA, a higher proportion of eicosapentaenoic acid (EPA) and of docosahexaenoic acid (DHA) were associated with lower odds of LGS (OR = 0.76; 95% CI: 0.63-0.93 and OR = 0.79; 95% CI: 0.67-0.95 respectively). Conversely, a higher arachidonic acid (AA):(EPA + DHA) ratio was associated with higher odds of LGS. Three main FA patterns were identified. A higher score on the FA pattern characterized by higher proportions of LC n-3 PUFAs was associated with lower odds of LGS (OR = 0.78; 95% CI: 0.67-0.90). CONCLUSIONS: A FA pattern mainly driven by high plasma concentrations of LC n-3 PUFAs is cross-sectionally associated with higher gait speed in community-dwelling older adults, while a higher AA:(EPA + DHA) ratio is associated with lower gait speed. These findings suggest a potential protective effect of n-3 PUFA on physical performance decline.

Comparison of total energy expenditure assessed by two devices in controlled and free-living conditions.

The objective of this study was to evaluate the validity of total energy expenditure (TEE) provided by Actiheart and Armband. Normal-weight adult volunteers wore both devices either for 17 hours in a calorimetric chamber (CC, n = 49) or for 10 days in free-living conditions (FLC) outside the laboratory (n = 41). The two devices and indirect calorimetry or doubly labelled water, respectively, were used to estimate TEE in the CC group and FLC group. In the CC, the relative value of TEE error was not significant (p > 0.05) for Actiheart but significantly different from zero for Armband, showing TEE underestimation (-4.9%, p < 0.0001). However, the mean absolute values of errors were significantly different between Actiheart and Armband: 8.6% and 6.7%, respectively (p = 0.05). Armband was more accurate for estimating TEE during sleeping, rest, recovery periods and sitting-standing. Actiheart provided better estimation during step and walking. In FLC, no significant error in relative value was detected. Nevertheless, Armband produced smaller errors in absolute value than Actiheart (8.6% vs. 12.8%). The distributions of differences were more scattered around the means, suggesting a higher inter-individual variability in TEE estimated by Actiheart than by Armband. Our results show that both monitors are appropriate for estimating TEE. Armband is more effective than Actiheart at the individual level for daily light-intensity activities.

Energy expenditure, spontaneous physical activity and with weight gain in kidney transplant recipients.

BACKGROUND & AIMS: Alterations in energy metabolism could trigger weight gain after renal transplantation. METHODS: Nineteen transplanted non-diabetic men, 53 ± 1.6 years old, receiving calcineurin inhibitors but no corticosteroids were studied. They were compared with nine healthy men matched for height, age and lean body mass. Daily energy expenditure and its components (sleeping, basal and absorptive metabolic rates) were analyzed for 24 h in calorimetric chambers and for 4 days in free living conditions using calibrated accelerometry. Other variables known to influence energy expenditure were assessed: body composition, physical activity, 4-day food intake, drug consumption, serum C-reactive protein, interleukin-6, thyroid and parathyroid hormones, and epinephrine. Transplant recipients who gained more than 5% body weight after transplantation (n = 11, +11.0 ± 1.5 kg) were compared with those who did not (n = 8) and with the controls. RESULTS: Weight gain compared with non-weight gain patients and controls exhibited higher fat mass without change in lean body mass. Daily, sleeping and resting energy expenditure adjusted for lean body mass was significantly higher in non-weight gain (167.1 ± 4.2 kJ/kg/lean body mass/24 h, P < 0.05) compared with weight gain patients (147.4 ± 3.6) and controls (146.1 ± 4.6). Weight gain compared with controls and non-weight gain subjects had lower free living physical activity and a higher consumption of antihypertensive drugs and ß-blockers. CONCLUSIONS: After kidney transplantation, weight gain patients were characterized by lower adjusted energy expenditure, reduced spontaneous physical activity but a more sedentary life style and a trend toward a higher energy intake explaining the reason they gained weight. The nWG KTR had increased resting and sleeping EE which protected them from weight gain. Such hypermetabolism was also observed in 24-h EE measurements. By comparison with the nWG patients, the WG transplant recipients were characterized by higher ß-blocker consumption. These data could be helpful in the prevention of weight gain in kidney transplant recipients.

Surgical weight loss: impact on energy expenditure.

Diet-induced weight loss is often limited in its magnitude and often of short duration, followed by weight regain. On the contrary, bariatric surgery now commonly used in the treatment of severe obesity favors large and sustained weight loss, with resolution or improvement of most obesity-associated comorbidities. The mechanisms of sustained weight loss are not well understood. Whether changes in the various components of energy expenditure favor weight maintenance after bariatric surgery is unclear. While the impact of diet-induced weight loss on energy expenditure has been widely studied and reviewed, the impact of bariatric surgery on total energy expenditure, resting energy expenditure, and diet-induced thermogenesis remains unclear. Here, we review data on energy expenditure after bariatric surgery from animal and human studies. Bariatric surgery results in decreased total energy expenditure, mainly due to reduced resting energy expenditure and explained by a decreased in both fat-free mass and fat mass. Limited data suggest increased diet-induced thermogenesis after gastric bypass, a surgery that results in gut anatomical changes and modified the digestion processes. Physical activity and sustained intakes of dietary protein may be the best strategies available to increase non-resting and then total energy expenditure, as well as to prevent the decline in lean mass and resting energy expenditure.

Contributing factors and variability of energy expenditure in non-obese, obese, and post-obese adolescents.

Energy expenditure (EE) is a major determinant of energy balance and body composition. The objectives of this paper were to review the contributing factors of the main components of daily EE (DEE) and the inter-individual variability in these components in non-obese (NOb), obese (Ob), and post-obese (POb) adolescents. Body composition especially fat-free mass (FFM), is the major determinant of the basal metabolic rate which contributes 50-70% of DEE, whereas fat mass (FM) is a significant factor only in obese subjects. Physical activity is the second main variation factor of DEE, whereas growth, the thermic effect of food, and thermoregulation are generally of marginal importance. The energy costs and EE associated with various sedentary and physical activities were assessed in NOb, Ob and POb subjects both in standardised and in free-living conditions. The interindividual variability of DEE is high, even after adjustment for body composition, mainly because of great differences in time devoted to the various physical activities. DEE and EE associated with sleep and sedentary activities are significantly higher in Ob than in NOb, but not after adjustment for FFM. On the contrary, EE associated with physical activities is not significantly different between Ob and NOb adolescents, but 61% lower in Ob subjects after adjustment for body composition. Multidisciplinary weight-reduction programmes including moderate energy restriction and physical training result in great FM loss, maintenance of FFM, improvement of physical capacities, but reductions in organ and tissue metabolic rate and in EE associated with the various sedentary and physical activities, which may favour body weight regain in the less active POb subjects.

[Assessment on the usual physical activity in overweight and obese adolescents]. / Evaluation de l'activité physique habituelle des adolescents en surpoids ou obèses.

OBJECTIVES: To develop a simple, rapid, and unbiased test to assess usual physical activity in overweight adolescents during a routine medical consultation. METHODS: Adolescents were selected. Their heart rate (HR) and blood pressure (BP) were measured at rest and when standing, before the beginning of the test. Subjects went up and down a 2-step apparatus during 4 minutes at a rate of 92 steps/min. HR was monitored. At the end of the test, the HR was noted and BP measured immediately. The effects of usual physical activity and gender on HR and BP were tested by ANOVA. In addition, an activity questionnaire was filled in by 43 subjects over 7 days and given to the doctor who completed the information during the visit and assessed usual physical activity. RESULTS: 56 adolescents of both sexes, aged 10-17 years (31 sedentary [S] overweight, and 25 active [A] post-obese subjects) underwent a step-test. The increase in HR during the test was significantly higher in S than in A subjects (66.2 +/- 2.3 vs 52.3 +/- 2.5 bpm, p < 0.001). However, the variations in BP did not supply reliable assessment of usual physical activity. The activity questionnaire had been filled in satisfactorily by 72% of subjects. In 95% of cases, the classification of subjects as S or A by the step-test agreed with the classification based on the questionnaire. CONCLUSION: The step-test provided the rapid and reliable assessment of usual physical activity of the children (from 6-7 years of age) in 95% of cases during a routine consultation (30 min), and the activity questionnaire enabled the doctor to check the conclusions of the step-test and recommend to the parents physical activities adapted to the physical capacities of their children.