Nutrition in critically ill children with acute kidney injury on continuous kidney replacement therapy: a 2023 executive summary.

OBJECTIVES: Nutrition plays a vital role in the outcome of critical illness in children, particularly those with acute kidney injury. Currently, there are no established guidelines for children with acute kidney injury treated with continuous kidney replacement therapy. Our objective was to create clinical practice points for nutritional assessment and management in critically ill children with acute kidney injury receiving continuous kidney replacement therapy. METHODS: An electronic search using PubMed and an inclusive academic library search (including MEDLINE, Cochrane, and Embase databases) was conducted to find relevant English-language articles on nutrition therapy for children (<18 y of age) receiving continuous kidney replacement therapy. RESULTS: The existing literature was reviewed by our work group, comprising pediatric nephrologists and experts in nutrition. The modified Delphi method was then used to develop a total of 45 clinical practice points. The best methods for nutritional assessment are discussed. Indirect calorimetry is the most reliable method of predicting resting energy expenditure in children on continuous kidney replacement therapy. Schofield equations can be used when indirect calorimetry is not available. The non-intentional calories contributed by continuous kidney replacement therapy should also be accounted for during caloric dosing. Protein supplementation should be increased to account for the proteins, peptides, and amino acids lost with continuous kidney replacement therapy. CONCLUSIONS: Clinical practice points are provided on nutrition assessment, determining energy needs, and nutrient intake in children with acute kidney injury and on continuous kidney replacement therapy based on the existing literature and expert opinions of a multidisciplinary panel.

Energy Guidance Using Indirect Calorimetry for Intestinal Failure Patients with Home Parenteral Nutrition: The Right Bag Right at the Start.

Intestinal failure is defined as the inability to absorb the minimum of macro and micronutrients, minerals and vitamins due to a reduction in gut function. In a subpopulation of patients with a dysfunctional gastrointestinal system, treatment with total or supplemental parenteral nutrition is required. The golden standard for the determination of energy expenditure is indirect calorimetry. This method enables an individualized nutritional treatment based on measurements instead of equations or body weight calculations. The possible use and advantages of this technology in a home PN setting need critical evaluation. For this narrative review, a bibliographic search is performed in PubMed and Web of Science using the following terms: 'indirect calorimetry', 'home parenteral nutrition', 'intestinal failure', 'parenteral nutrition', 'resting energy expenditure', 'energy expenditure' and 'science implementation'. The use of IC is widely embedded in the hospital setting but more research is necessary to investigate the role of IC in a home setting and especially in IF patients. It is important that scientific output is generated in order to improve patients' outcome and develop nutritional care paths.

Point-Counterpoint: Indirect Calorimetry Is Essential for Optimal Nutrition Therapy in the Intensive Care Unit.

Iatrogenic malnutrition and underfeeding are ubiquitous in intensive care units (ICUs) worldwide for prolonged periods after ICU admission. A major driver leading to the lack of emphasis on timely ICU nutrition delivery is lack of objective data to guide nutrition care. If we are to ultimately overcome current fundamental challenges to effective ICU nutrition delivery, we must all adopt routine objective, longitudinal measurement of energy targets via indirect calorimetry (IC). Key evidence supporting the routine use of IC in the ICU includes (1) universal societal ICU nutrition guidelines recommending IC to determine energy requirements; (2) data showing predictive equations or body weight calculations that are consistently inaccurate and correlate poorly with measured energy expenditure, ultimately leading to routine overfeeding and underfeeding, which are both associated with poor ICU outcomes; (3) recent development and worldwide availability of a new validated, accurate, easy-to-use IC device; and (4) recent data in ICU patients with coronavirus disease 2019 (COVID-19) showing progressive hypermetabolism throughout ICU stay, emphasizing the inaccuracy of predictive equations and marked day-to-day variability in nutrition needs. Thus, given the availability of a new validated IC device, these findings emphasize that routine longitudinal IC measures should be considered the new standard of care for ICU and post-ICU nutrition delivery. As we would not deliver vasopressors without accurate blood pressure measurements, the ICU community is only likely to embrace an increased focus on the importance of early nutrition delivery when we can consistently provide objective IC measures to ensure personalized nutrition care delivers the right nutrition dose, in the right patient, at the right time to optimize clinical outcomes.

Indirect calorimetry: The 6 main issues.

BACKGROUND AND AIMS: Optimal nutritional therapy, including the individually adapted provision of energy, is associated with better clinical outcomes. Indirect calorimetry is the best tool to measure and monitor energy expenditure and hence optimize the energy prescription. Similarly to other medical techniques, indications and contra-indications must be acknowledged to optimise the use of indirect calorimetry in clinical routine. Measurements should be repeated to enable adaptation to the clinical evolution, as energy expenditure may change substantially. This review aims at providing clinicians with the knowledge to routinely use indirect calorimetry and interpret the results. METHOD: We performed a bibliographic research of publications referenced in PubMed using the following terms: "indirect calorimetry", "energy expenditure", "resting energy expenditure", "VCO2", "VO2", "nutritional therapy". We included mainly studies published in the last ten years, related to indirect calorimetry principles, innovations, patient's benefits, clinical use in practice and medico-economic aspects. RESULTS: We have gathered the knowledge required for routine use of indirect calorimetry in clinical practice and interpretation of the results. A few clinical cases illustrate the decision-making process around its application for prescription, and individual optimisation of nutritional therapy. We also describe the latest technical innovations and the results of tailoring nutrition therapy according to the measured energy expenditure in medico-economic benefits. CONCLUSION: The routine use of indirect calorimetry should be encouraged as a strategy to optimize nutrition care.

Energy expenditure, growth, and nutritional therapy in appropriate and small for gestational age preterm infants / Gasto energético, crescimento e terapia nutricional em recém-nascidos pré-termo adequados e pequenos para idade gestacional

Abstract Objective: To evaluate the resting energy expenditure, growth, and quantity of energy and macronutrients intake in a group of preterm newborns. Methods: The cohort study was performed with appropriate and small for gestational age preterm infants (birth weight lower than 1500 g or gestational age < 32 weeks). Resting energy expenditure was measured using indirect calorimetry on the 7th, 14th, 21st, and 28th days of life, and at discharge. Length, head circumference and body weight were assessed weekly. Nutritional therapy was calculated during the hospital stay and the information for each type of food was recorded in software that calculates the total amount of energy and macronutrients. Results: 61 preterm infants were followed; 43 appropriate and 18 small for gestational age infants. There was no statistical difference for resting energy expenditure between the groups, and it increased from the first to the fourth week of life (appropriate: 26.3% and small: 21.8%). Energy intake in the first two weeks of life was well below the energy requirement. Conclusion: Considering that the results demonstrate high energy expenditure during the first weeks of life, there is an evident need to provide the best quality of nutrition for each child in the first weeks of life so that preterm infants with or without intrauterine growth restriction can achieve their maximum potential for growth and development.

Resumo Objetivo: Avaliar o gasto energético de repouso, o crescimento e a quantidade ofertada de energia e macronutrientes em um grupo de recém-nascidos pré-termo. Método: Foi feito estudo de coorte com recém-nascidos pré-termo adequados e pequenos para a idade gestacional (peso de nascimento inferior a 1.500 gramas ou idade gestacional < 32 semanas). O gasto energético foi avaliado com a calorimetria indireta nos dias 7°, 14°, 21°, 28° dias de vida e alta hospitalar. Medidas do comprimento, perímetro cefálico e peso corporal foram avaliadas semanalmente. A terapia nutricional foi calculada durante a internação do recém-nascido e as informações de cada tipo de alimentação foram registradas em um software que calcula a quantidade total de energia e macronutrientes. Resultados: Foram acompanhados 61 recém-nascidos, sendo 43 adequados e 18 pequenos para idade gestacional. O gasto energético de repouso não apresentou diferença estatística entre os grupos e aumentou entre a primeira e quarta semana de vida (adequados: 26,3% e pequenos: 21,8%). O aporte energético nas duas primeiras semanas de vida mostrou-se bem abaixo do requerimento energético mensurado pela calorimetria. Conclusão: Considerando os resultados que demonstram um gasto energético alto ao longo das primeiras semanas de vida, fica evidente a necessidade de fornecer ao recém-nascido pré-termo um melhor aporte energético já nas primeiras semanas de vida, para que os neonatos com ou sem restrição intrauterina possam atingir o seu potencial máximo de crescimento e desenvolvimento.

Evaluation of an activity monitor for use in pregnancy to help reduce excessive gestational weight gain.

BACKGROUND: Excessive weight gain during pregnancy increases the risk for negative effects on mother and child during pregnancy, delivery, and also postnatally. Excessive weight gain can be partially compensated by being sufficiently physically active, which can be measured using activity trackers. Modern activity trackers often use accelerometer data as well as heart rate data to estimate energy expenditure. Because pregnancy affects the metabolism and cardiac output, it is not evident that activity trackers that are calibrated to the general population can be reliably used during pregnancy. We evaluated whether an activity monitor designed for the general population is sufficiently accurate for estimating energy expenditure in pregnant women. METHODS: Forty pregnant women (age: 30.8 ± 4.7 years, BMI: 25.0 ± 4.0) from all three trimesters performed a 1-h protocol including paced and self-paced exercise activities as well as household activities. We tracked reference energy expenditure using indirect calorimetry and used equivalence testing to determine whether the estimated energy expenditure from the activity monitor was within the limits of equivalence. RESULTS: Overall we found an averaged underestimation of 10 kcal (estimated energy expenditure was 97% of the reference measurement). The 90% CI for the cumulative total energy expenditure was 94-100%. The activities of self-paced cycling, household activities, stair-walking, and yoga had one of their equivalence boundaries outside a 80-125% range of equivalence; for exercise on a cross-trainer, for self-paced and fixed-pace walking, fixed-paced cycling, and resting, the estimations were within the limits of equivalence. CONCLUSIONS: We conclude that the activity monitor is sufficiently accurate for every-day use during pregnancy. The observed deviations can be accounted for and are acceptable from a statistical and an applied perspective because the positive and negative deviations that we observed cancel out to an accurate average energy expenditure over a day, and estimations during exercise are sufficiently accurate to enable coaching on physical activity. The positive and negative deviations themselves were relatively small. Therefore, the activity monitor can be used to help in preventing excessive weight gain during pregnancy by accurately tracking physical activity.

Determination of net energy content of soybean oil fed to growing pigs using indirect calorimetry.

The objectives of this experiment were: (i) to determine the net energy (NE) of soybean oil (SBO) fed to growing pigs using indirect calorimetry (IC); and (ii) to evaluate the effects of inclusion rate of SBO on heat production, oxidative status and nutrient digestibility in growing pigs. Eighteen growing barrows were allotted to three diets based on completely randomized design with six replicate pigs (period) per diet. Diets included a corn-soybean meal basal diet and two test diets containing 5% or 10% SBO at the expense of corn and soybean meal. During each period, pigs were individually housed in metabolism crates for 14 days, including 7 days to adapt to feed, metabolism crate and environmental conditions. On day 8, pigs were transferred to the open-circuit respiration chambers for measurement of daily O2 consumption and CO2 and CH4 production. During this time, pigs were fed one of the three diets at 2.4 MJ metabolizable energy/kg body weight (BW)0.6 /day. Total feces and urine were collected and daily total heat production (THP) was measured from days 9 to 13 and fasted on day 14 to evaluate their fasting heat production (FHP). The results show that trends of decreased apparent total tract digestibility of neutral detergent fiber (linear, P = 0.09) and acid detergent fiber (linear, P = 0.07) were observed as the content of dietary lipids increased. The average THP for the three diets were 1326, 1208 and 1193 kJ/kg BW0.6 /day, respectively. The FHP of pigs averaged 843 kJ/kg BW0.6 /day and was not affected by diet characteristics. A reduction of the respiratory quotients in the fed state as the inclusion level of SBO increased was observed. In conclusion, the NE values of SBO we determined by indirect calorimetry were 33.45 and 34.05 MJ/kg dry matter under two inclusion levels. THP could be largely reduced when SBO is added in the feed, but the THP of SBO included at 5% in a corn-soybean meal diet is not different from the THP of SBO included at 10%.

Energy expenditure, growth, and nutritional therapy in appropriate and small for gestational age preterm infants.

OBJECTIVE: To evaluate the resting energy expenditure, growth, and quantity of energy and macronutrients intake in a group of preterm newborns. METHODS: The cohort study was performed with appropriate and small for gestational age preterm infants (birth weight lower than 1500g or gestational age<32 weeks). Resting energy expenditure was measured using indirect calorimetry on the 7th, 14th, 21st, and 28th days of life, and at discharge. Length, head circumference and body weight were assessed weekly. Nutritional therapy was calculated during the hospital stay and the information for each type of food was recorded in software that calculates the total amount of energy and macronutrients. RESULTS: 61 preterm infants were followed; 43 appropriate and 18 small for gestational age infants. There was no statistical difference for resting energy expenditure between the groups, and it increased from the first to the fourth week of life (appropriate: 26.3% and small: 21.8%). Energy intake in the first two weeks of life was well below the energy requirement. CONCLUSION: Considering that the results demonstrate high energy expenditure during the first weeks of life, there is an evident need to provide the best quality of nutrition for each child in the first weeks of life so that preterm infants with or without intrauterine growth restriction can achieve their maximum potential for growth and development.

Energy Expenditure in Vinyasa Yoga Versus Walking.

BACKGROUND: Whether the energy cost of vinyasa yoga meets the criteria for moderate-to-vigorous physical activity has not been established. PURPOSE: To compare energy expenditure during acute bouts of vinyasa yoga and 2 walking protocols. METHODS: Participants (20 males, 18 females) performed 60-minute sessions of vinyasa yoga (YOGA), treadmill walking at a self-selected brisk pace (SELF), and treadmill walking at a pace that matched the heart rate of the YOGA session (HR-Match). Energy expenditure was assessed via indirect calorimetry. RESULTS: Energy expenditure was significantly lower in YOGA compared with HR-Match (difference = 79.5 ± 44.3 kcal; P < .001) and SELF (difference = 51.7 ± 62.6 kcal; P < .001), but not in SELF compared with HR-Match (difference = 27.8 ± 72.6 kcal; P = .054). A similar pattern was observed for metabolic equivalents (HR-Match = 4.7 ± 0.8, SELF = 4.4 ± 0.7, YOGA = 3.6 ± 0.6; P < .001). Analyses using only the initial 45 minutes from each of the sessions, which excluded the restorative component of YOGA, showed energy expenditure was significantly lower in YOGA compared with HR-Match (difference = 68.0 ± 40.1 kcal; P < .001) but not compared with SELF (difference = 15.1 ± 48.7 kcal; P = .189). CONCLUSIONS: YOGA meets the criteria for moderate-intensity physical activity. Thus, YOGA may be a viable form of physical activity to achieve public health guidelines and to elicit health benefits.

Estimación del gasto energético en el paciente quemado mediante la utilización de ecuaciones predictivas; revisión bibliográfica / Energy expenditure prediction equations in burn patients; bibliographic review

Introducción: La valoración de las necesidades calóricas del paciente quemado se ha basado en la medición del gasto energético en reposo (GER) mediante calorimetría indirecta, no siempre disponible en las unidades de quemados, o en su estimación mediante el uso de ecuaciones predictivas. Objetivos: analizar la historia y estado del arte del uso de las ecuaciones predictivas de GER en el paciente quemado crítico, y determinar su validez. Métodos: revisión bibliográfica de estudios y revisiones en español y en inglés entre 1989 y 2013. Resultados: Se han diseñado más de 190 ecuaciones para estimar el gasto energético que pueden ser imprecisas por estar basadas en mediciones con metodología heterogénea y en grupos heterogéneos. Describimos los distintos parámetros que aplican las distintas fórmulas predictivas (factores de estrés y de actividad, superficie corporal quemada, tiempo desde la lesión, masa corporal magra), la influencia de la edad en el cálculo de las necesidades caló- ricas y las fórmulas más utilizadas en el momento actual. También describimos los artículos que evalúan exactitud de las fórmulas cuando se comparan con mediciones mediante calorimetría indirecta. Conclusiones: Las ecuaciones predictivas son poco precisas en general en el paciente quemado. Hasta que se desarrollen ecuaciones predictivas más precisas, recomendamos calcular los requerimientos nutricionales de los pacientes quemados basándose en la medición del gasto energético por calorimetría indirecta (AU)

Introduction: The estimation of the caloric requirements of the burn patient is based on the measurement of his resting energy expenditure (REE) via indirect calorimetry, which is not available in all Burn Units, or its estimation by means of predictive equations. Goals: we analyze the history and state of art of the use of REE predictive equations in burn patients, and determine their validity. Methods: bibliographic review of the studies and reviews written in English and Spanish between 1989 and 2013. Results: More than 190 equations have been designed to estimate energy expenditure. These equations can be imprecise because they are based on measurements with a heterogeneous methodology and in heterogeneous groups. We describe the different parameters that are used in the different equations (stress and activity factors, total burn surface area, post-burn day, lean body mass), the influence of age in the calculation of the caloric requirements, and the most commonly used equations nowadays. We also describe the articles that evaluate the accuracy of the predictive equations when compared to REE indirect calorimetry measurements. Conclusions: Predictive equations are not precise in general in the burn patient. Until more accurate predictive equations are developed, we recommend calculation of the nutritional requirements in burn patients based on the energy expenditure measurement via indirect calorimetry (AU)

Effects of novel capsinoid treatment on fatness and energy metabolism in humans: possible pharmacogenetic implications.

BACKGROUND: Capsinoids from the Capsicum genus of plants are nonpungent capsaicin-related substances with effects on metabolism and body weight in animals. OBJECTIVES: Our objectives were to explore the safety and efficacy of capsinoids taken orally (6 mg/d) for weight loss, fat loss, and change in metabolism and to examine whether candidate genes are predictors of capsinoid response. DESIGN: This was a 12-wk, placebo-controlled, double-blind, randomized study. Eligibility criteria included a body mass index (BMI; in kg/m(2)) of 25-35. Body weight was measured, and dual-energy X-ray absorptiometry, indirect calorimetry (men only), and genotyping were conducted. RESULTS: Forty women and 40 men with a mean (+/- SD) age of 42 +/- 8 y and BMI of 30.4 +/- 2.4 were randomly assigned to a capsinoid or placebo group. Capsinoids were well tolerated. Mean (+/- SD) weight change was 0.9 +/- 3.1 and 0.5 +/- 2.4 kg in the capsinoid and placebo groups, respectively (P = 0.86). There was no significant group difference in total change in adiposity, but abdominal adiposity decreased more (P = 0.049) in the capsinoid group (-1.11 +/- 1.83%) than in the placebo group (-0.18 +/- 1.94%), and this change correlated with the change in body weight (r = 0.46, P < 0.0001). Changes in resting energy expenditure did not differ significantly between groups, but fat oxidation was higher at the end of the study in the capsinoid group (least-squares mean difference: 21.0 mg/min; P = 0.06). Of 13 genetic variants tested, TRPV1 Val585Ile and UCP2 -866 G/A correlated significantly with change in abdominal adiposity. CONCLUSIONS: Treatment with 6 mg/d capsinoids orally appeared to be safe and was associated with abdominal fat loss. Capsinoid ingestion was associated with an increase in fat oxidation that was nearly significant. We identified 2 common genetic variants that may be predictors of therapeutic response.

Energy expenditure in growing preterm infants receiving massage therapy.

OBJECTIVE: Massage therapy has been consistently shown to increase weight gain in preterm infants. The mechanism of this presumed improved metabolic efficiency is unknown. We conducted the following trial to test the hypothesis that massage therapy reduces energy expenditure in growing healthy preterm infants. STUDY DESIGN: A prospective, randomized, cross-over design study was conducted in 10 healthy, appropriate weights for gestational age, gavage fed preterm infants. Each infant was studied twice: after a period of either 5 days of massage therapy, or after a period of 5 days without massage therapy. Infants were randomized to 5 days of massage followed by 5 days of no massage (n = 5) or the opposite sequence (n = 5). During the massage therapy period, massage was provided daily for three 15 minute periods at the beginning of each 3 hour period every morning. Metabolic measurements were performed by indirect calorimetry, using the Deltatrac II Metabolic cart. RESULTS: Energy expenditure was significantly lower in infants after the 5 day massage therapy period (59.6 +/- 3.6 Kcal/Kg/ 24 hours) than after the period without (63.1 +/- 5.4 Kcal/Kg/ 24 hours) (p = 0.05). CONCLUSIONS: Energy expenditure is significantly lowered by 5 days of massage therapy in metabolically and thermally stable preterm infants. This decrease in energy expenditure may be in part responsible for the enhanced growth caused by massage therapy.

Conjugated linoleic acid supplementation alters the 6-mo change in fat oxidation during sleep.

BACKGROUND: Conjugated linoleic acid (CLA) is a family of positional and geometric isomers with 2 conjugated double bonds formed from linoleic acid and linolenic acid. CLA has a wide range of biological effects, including body fat reduction. OBJECTIVE: The aim of our study was to determine CLA's effects on energy expenditure, macronutrient utilization, and dietary fat oxidation in overweight adults after 6 mo of supplementation. DESIGN: We recruited 23 subjects from our main CLA efficacy study who were receiving either 4 g/d of 78% active CLA isomers (3.2 g/d: 39.2% cis-9,trans-11 and 38.5% trans-10,cis-12) or 4 g/d of safflower oil. Energy expenditure and substrate utilization were measured before and after 6 mo of CLA supplementation by using whole-room indirect calorimetry. Dietary fat oxidation was measured by using stable isotope-labeled oleate and palmitate. RESULTS: Our substudy detected a difference in the change in fat utilization between the CLA (4 +/- 8 g) and placebo (-7 +/- 11 g) groups during sleep after 6 mo of supplementation. In addition, the percentage of energy from protein was reduced during sleep in the CLA group (CLA: -3.3 +/- 2.6%; placebo: 0.3 +/- 5.7%). We also detected a difference in the change in energy expenditure during sleep (CLA: 0 +/- 38 kcal; placebo: -43 +/- 90 kcal). We did not detect a change in labeled dietary fat oxidation after 6 mo of CLA supplementation given with a breakfast meal. CONCLUSION: Mixed isomer CLA supplementation, but not placebo, positively altered fat oxidation and energy expenditure during sleep.

Increase in the thermic effect of food in women by adrenergic amines extracted from citrus aurantium.

OBJECTIVE: To compare the thermic response to a meal between men and women of varied body composition and to determine whether adrenergic amines extracted from citrus aurantium (CA) induce an increase in metabolic rate and enhance the thermic response to the meal. RESEARCH METHODS AND PROCEDURES: In 30 healthy weight-stable subjects (17 women, 13 men; BMI: 20 to 42 kg/m2), body composition was determined by bioimpedance analysis followed by resting energy expenditure for 20 minutes, and the thermic effect of food (TEF) of a 1.7-MJ, 30-gram protein meal was determined intermittently for 300 minutes by indirect calorimetry. In a subset of 22 subjects, the TEFs of CA alone and when added to the same 1.7-MJ meal were determined. Blood pressure and pulse before and throughout the studies and catecholamine excretion were determined. RESULTS: TEF was significantly lower in women than men (152 +/- 7 vs. 190 +/- 12 kJ and 8.8 +/- 0.4% vs. 11.0 +/- 0.7% of meal), independently of age and magnitude of adiposity. The thermic response to CA alone was higher in men, but, when added to the meal, CA increased TEF only in women and to values no longer different from men. CA had no effect on blood pressure and pulse rate but increased epinephrine excretion by 2.4-fold. DISCUSSION: A 20% lower TEF in women suggests a diminished sympathetic nervous system response to meals, because with CA, TEF increased by 29% only in women. However, this acute response may not translate into a chronic effect or a clinically significant weight loss over time.

Effect of lean system 7 on metabolic rate and body composition.

OBJECTIVE: This study evaluated whether a commercial weight-loss product (Lean System 7) would result in less reduction in resting metabolic rate (RMR) in overweight subjects on a calorie-restricted diet and exercise regimen than in subjects using diet and exercise alone. METHODS: In this randomized, double-blind, placebo-controlled study, healthy overweight adults were given three capsules of a commercial weight-loss product twice daily or an identical placebo and followed a calorie-restricted diet and an exercise program for 8 wk. RMR, body weight, body mass index, waist and hip circumferences, and body composition by dual-energy x-ray absorptiometry were measured at baseline and week 8. An intention-to-treat analysis was performed. RESULTS: Of 47 adults enrolled, 35 completed the study. Subjects taking the commercial weight-loss product had a significant (P = 0.03) increase in RMR, 7.2% increase versus 0.7% decrease in the placebo group. Subjects taking the commercial weight-loss product also had a significant (P = 0.04) decrease in hip circumference, 3.78 cm versus 2.07 cm in the placebo group. There were no other statistically significant differences in any other outcome variable, diet composition, exercise compliance, or adverse events. CONCLUSION: The results of this study showed that administration of a commercial weight-loss product to overweight adults in conjunction with a calorie-restricted diet and moderate exercise program effectively reverses the decrease in RMR associated with calorie restriction within this study population. The commercial weight-loss product was well tolerated, and there were no serious adverse events over the 8 wk studied.

The acute effects of olive oil v. cream on postprandial thermogenesis and substrate oxidation in postmenopausal women.

The influence of the source of dietary fat on postprandial thermogenesis and substrate oxidation rates, was examined in twelve postmenopausal women aged 57-73 years, with BMI 21.9-38.3 kg/m(2). A single blind, randomised, paired comparison of two high-fat, isoenergetic, mixed test meals was conducted. The major source of fat was either cream (CREAM) or extra virgin olive oil (EVOO). RMR, diet-induced thermogenesis (DIT) and substrate oxidation rates over 5 h were measured by indirect calorimetry. There were no differences in body weight, RMR, fasting carbohydrate or fat oxidation rates between the two occasions. DIT (EVOO 97 (SD 46) v. CREAM 76 (SD 69) kJ/5 h and EVOO 5.2 (SD 2.5) v. CREAM 4.1 (SD 3.7)% energy) did not differ between the two test meals. The postprandial increase in carbohydrate oxidation rates, relative to their respective fasting values (DeltaCOX), was significantly lower following the EVOO meal (EVOO 10.6 (SD 8.3) v. CREAM 17.5 (SD 10) g/5 h; paired t test, P=0.023), while postprandial fat oxidation rates (DeltaFOX) were significantly higher (EVOO 0.0 (SD 4.4) v. CREAM -3.6 (sd 4.0) g/5 h; P=0.028). In the eight obese subjects, however, DIT was significantly higher following the EVOO meal (EVOO 5.1 (SD 2.0) v. CREAM 2.5 (sd 2.9) %; P=0.01). This was accompanied by a significantly lower DeltaCOX (EVOO 10.9 (SD 9.9) v. CREAM 17.3 (SD 10.5) g/5 h; P=0.03) and significantly higher DeltaFOX (EVOO 0.11 (SD 4.4) v. CREAM -4.1 (SD 4.5) g/5 h, P=0.034). The present study showed that olive oil significantly promoted postprandial fat oxidation and stimulated DIT in abdominally obese postmenopausal women.

Effect of acute and chronic branched-chain amino acids on energy metabolism and muscle performance.

The aim of this study was to report the effects of acute and chronic branched-chain amino acids (BCAA) administration on energy metabolism and muscle performance. In the acute study which was double-blind, cross-over and placebo-controlled, 12 healthy male volunteers were administered orally on two consecutive days either BCAA (14.4 g/day) or isocaloric placebo; this was followed by measurement of oxygen consumption (VO2) and carbon dioxide production (VCO2) for 180 min by indirect calorimetry. In the chronic study, 10 healthy male volunteers were supplemented with BCAA (14.4 g/day) for 30 days. Before (T0) and after (T1) chronic BCAA administration, VO2, arm muscle area (AMA) and maximal voluntary contraction of forearm muscles (grip strength, GS) were evaluated. Acute study: Both meals increased mean respiratory quotient (RQ) from baseline: in the placebo group, this increase was short-term only (between 15 and 60 min), while this effect on RQ lasted for 120 min in the BCAA group. Moreover, between 30 and 90 min, mean RQ was significantly higher in the BCAA group than in the placebo group. Chronic study: GS increased significantly following chronic BCAA administration without significant changes in the AMA. At T0, VO2 increased significantly during the GS test, whereas at T1 no significant increase was observed. In conclusion, no excess thermogenesis could be detected as compared with placebo following acute BCAA administration, indirectly suggesting a relevant contribution of peripheral catabolic (bypassing liver) pathway to BCAA metabolism; furthermore, chronic BCAA supplementation improved the physical fitness of untrained healthy subjects, as demonstrated by the lack of 02 uptake increase during sustained hand grip test.

Dose-response relationship between fat ingestion and oxidation: quantitative estimation using whole-body calorimetry and 13C isotope ratio mass spectrometry.

OBJECTIVE: To determine dose-dependent relationship between ingested fat and its oxidation in the immediate post-prandial period in humans. DESIGN: Subjects were randomly selected for the study at the Dunn Clinical Nutrition Centre, Cambridge, UK. Subjects ingested naturally enriched 13C corn-oil doses (range 20-140g) in a whole-body indirect calorimeter, and were studied for 8 h. Ingested fat oxidation was estimated from the subject's breath 13C enrichment and total carbon dioxide production. Total fat and carbohydrate oxidation were estimated from non-protein oxygen and carbon dioxide exchanges. Endogenous fat oxidation was estimated as the difference between total fat and ingested fat oxidation. RESULTS: The amount of fat dose oxidized was nonlinearly related to the amount ingested. On average, 25.6+/-2.7% of the mean fat dose was oxidized. A significant (r = - 0.72, P < 0.001) inverse correlation was found between the amount of fat dose and the proportion oxidized. Endogenous carbohydrate oxidation was negatively and significantly correlated to fat dose oxidized (r= -0.61, P < 0.01), but it was not correlated to endogenous fat oxidation. CONCLUSIONS: There was a nonlinear relationship between amount of fat dose and its quantity that was oxidized in the immediate post-prandial period. The inverse relationship between the size of the fat load and the proportion that was oxidized post-prandially implies increased dietary fat storage beyond about 50 g in a normal resting adult. This has important implications for 13CO2-based studies.

Accelerated post-glucose glycaemia and altered alliesthesia-test in Seasonal Affective Disorder.

BACKGROUND: Little is known about the link between mood, food and metabolic function in Seasonal Affective Disorder (SAD). METHODS: We investigated this link in a combined glucose tolerance-alliesthesia test in eight SAD patients in winter before and after one week light therapy, and in summer. RESULTS: SAD patients exhibited faster post-glucose glycaemic and insulin responses (p <0.05), and increased hedonic ratings of high concentrated sucrose solutions (p <0.035) when depressed in winter than when euthymic (one week after light treatment or in summer). CONCLUSIONS: The rapid glycaemic and insulin responses to an oral glucose load may be a result of accelerated gastric emptying. LIMITATIONS: The number of studied patients was rather small and no control group was studied in parallel. CLINICAL RELEVANCE: the more rapid post-glucose glycaemia may impair glucose homeostasis in depressed SAD patients.

Clinical application of the metabolic cart to the delivery of total parenteral nutrition.

In critically ill patients, the inaccuracy of predictive formulas for nutritional assessment often leads to inappropriate and potentially detrimental feeding regimens. This study evaluates the clinical utility of the metabolic cart in an urban university hospital setting. Twenty-six studies were performed on each of 26 patients (18 surgical, 8 medical) using an MMC Horizon metabolic cart. Although 58% of patients were overweight, 42% were still shown to have a kwashiorkorlike pattern of malnutrition. Three patients demonstrated a marasmic-like pattern. Fifteen percent of studies showed patients to be hypometabolic and 62% hypermetabolic. Harris-Benedict resting energy expenditure, based on actual or ideal body weight, underestimated needs; however, addition of a metabolic activity factor overestimated needs. Only 32% of patients were fed appropriately; 41% were underfed, and 27% were overfed. Urine area nitrogen correlated poorly with energy expenditure. Measured RQ appropriately reflected substrate utilization in 77% of studies; multiple factors may have caused differences between measured and predicted RQ in 23%. Use of the metabolic cart determines precisely the metabolic state, identifies problems with substrate utilization, and enables the physician to design the most efficacious nutritional regimen.