Position statement on nutrition therapy for overweight and obesity: nutrition department of the Brazilian association for the study of obesity and metabolic syndrome (ABESO-2022).

Obesity is a chronic disease resulting from multifactorial causes mainly related to lifestyle (sedentary lifestyle, inadequate eating habits) and to other conditions such as genetic, hereditary, psychological, cultural, and ethnic factors. The weight loss process is slow and complex, and involves lifestyle changes with an emphasis on nutritional therapy, physical activity practice, psychological interventions, and pharmacological or surgical treatment. Because the management of obesity is a long-term process, it is essential that the nutritional treatment contributes to the maintenance of the individual's global health. The main diet-related causes associated with excess weight are the high consumption of ultraprocessed foods, which are high in fats, sugars, and have high energy density; increased portion sizes; and low intake of fruits, vegetables, and grains. In addition, some situations negatively interfere with the weight loss process, such as fad diets that involve the belief in superfoods, the use of teas and phytotherapics, or even the avoidance of certain food groups, as has currently been the case for foods that are sources of carbohydrates. Individuals with obesity are often exposed to fad diets and, on a recurring basis, adhere to proposals with promises of quick solutions, which are not supported by the scientific literature. The adoption of a dietary pattern combining foods such as grains, lean meats, low-fat dairy, fruits, and vegetables, associated with an energy deficit, is the nutritional treatment recommended by the main international guidelines. Moreover, an emphasis on behavioral aspects including motivational interviewing and the encouragement for the individual to develop skills will contribute to achieve and maintain a healthy weight. Therefore, this Position Statement was prepared based on the analysis of the main randomized controlled studies and meta-analyses that tested different nutrition interventions for weight loss. Topics in the frontier of knowledge such as gut microbiota, inflammation, and nutritional genomics, as well as the processes involved in weight regain, were included in this document. This Position Statement was prepared by the Nutrition Department of the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO), with the collaboration of dietitians from research and clinical fields with an emphasis on strategies for weight loss.

Brazilian guide to nutrition in bariatric and metabolic surgery.

PURPOSE: Brazilian nutrition recommendations for bariatric and metabolic surgery aim to provide knowledge, based on scientific evidence, on nutritional practices related to different surgical techniques in the surgical treatment of obesity and metabolic diseases. MATERIALS AND METHODS: A systematic literature search was carried out with the appropriate MeSH terms using Medline/Pubmed/LiLACS and the Cochrane database, with the established criteria being based on the inclusion of articles according to the degree of recommendation and strength of evidence of the Classification of Recommendations, Evaluation, Development, and Evaluation System (GRADE). RESULTS: The recommendations that make up this guide were gathered to assist in the individualized clinical practice of nutritionists in the nutritional management of patients with obesity, including nutritional management in the intragastric balloon; pre and postoperative nutritional treatment and supplementation in bariatric and metabolic surgeries (adolescents, adults, elderly, pregnant women, and vegetarians); hypoglycemia and reactive hyperinsulinemia; and recurrence of obesity, gut microbiota, and inflammatory bowel diseases. CONCLUSION: We believe that this guide of recommendations will play a decisive role in the clinical practice of nutritionists who work in bariatric and metabolic surgery, with its implementation in health services, thus promoting quality and safety in the treatment of patients with obesity. The concept of precision nutrition is expected to change the way we understand and treat these patients.

Gut Microbiota Modifications and Weight Regain in Morbidly Obese Women After Roux-en-Y Gastric Bypass.

INTRODUCTION: The relationship between late post-bariatric surgery weight regain and gut microbiota is not completely understood. OBJECTIVE: To analyze the profile of gut microbiota among patients with and without late weight regain after post-Roux-en-Y gastric bypass (RYGB) and to compare it with a control group (CG) comprised of obese Brazilian individuals. METHODS: This is a cross-sectional study which enrolled 34 morbidly obese women divided into 3 groups: post-Roux-en-Y gastric bypass without (RYGB_non-regain), and with weight regain (RYGB_regain) at least 5 years after surgery, and a CG of preoperative individuals. Gut microbiota was determined by metagenomic analyses. RESULTS: The alpha diversity was higher in groups RYGB non-regain and RYGB regain when compared with CG (p < 0.05). Both RYGB non-regain and RYGB regain groups showed a lower abundance of the phylum Bacteroidetes when compared with CG (p < 0.01). The genera Bacteroides and SMB53 were increased in CG (p < 0.05). Group RYGB non-regain showed more abundance of the Akkermansia genus when compared with CG and group RYGB regain (p < 0.05). RYGB non-regain showed a greater abundance of the Phascolarctobacterium genus and lower of the SMB53 genus when compared with CG (p < 0.05). RYGB non-regain showed a greater abundance of the Phascolarctobacterium genus and a lower of the SMB53 genus when compared with CG (p < 0.05). CONCLUSION: The gut microbiota of individuals which presented late weight regain after RYGB was significantly different in comparison to individuals with a successful weight loss, a finding that points towards a significant role of gut microbiota on weight loss and maintenance after surgery.

The Optimal Nutritional Programme for Bariatric and Metabolic Surgery.

PURPOSE OF REVIEW: Bariatric surgery is the most effective treatment for severe and complex obesity; however, the risk of developing nutrient deficiencies varies based upon the type of surgery, degree of malabsorption, and level of nutrition intervention. There are numerous factors that can impact the nutrition status of a patient during their pre- and postoperative journey. We review the critical components and considerations needed in order to provide optimal nutrition care for patients with bariatric surgery. RECENT FINDINGS: A dietitian, specializing in bariatric surgery, is the best equipped healthcare provider to prepare and support patients in achieving and maintaining optimal nutrition status. We present best practices for both the pre- and postoperative nutrition-related phases of a patient's journey. The dietitian specialist is integral in the assessment and ongoing nutrition care of patients with bariatric surgery. Further consideration should be given to enable access for lifelong follow-up and monitoring.

Supplementation Adherence and Outcomes Among Pregnant Women After Bariatric Surgery.

PURPOSE: Most patients undergoing bariatric surgery (BS) are fertile women whose postoperative (post-op) hormonal balance and weight loss increases fertility, frequently leading to pregnancy. This study aims to analyze supplementation adherence of pregnant women after BS and perinatal outcomes. MATERIALS AND METHODS: This retrospective study analyzed records from women after BS who consulted nutritionists at least twice during pregnancy. Each patient received nutritional guidance about vitamin and mineral supplementation and protein intake. Demographic data, body mass index (BMI), percentage of weight loss (%WL) at conception, maximum post-op BMI and %WL, post-op time at conception, supplementation adherence, biochemical data, possible gestational complications, and infant's birth weight were collected. RESULTS: Data was obtained from 23 women (mean age 33 ± 4 years). On average, patients became pregnant 43 months after surgery. The mean preoperative BMI was 40.2 kg/m2, the maximum post-op %WL was 36.6%, and the mean %WL at conception was 32.0%. No gestational intercurrence was related to biochemical data. Supplementation adherence was 34.7% for one multivitamin and 34.7% for two multivitamins; 43.5% for iron, 43.5% for omega 3, 39.1% for folic acid, 17.4% for B complex, and 60.8% for calcium. Mean infant birth weight was 3.0 kg, and it was not associated with maximum %WL, % WL at conception, and time since BS at conception. CONCLUSION: Our data indicate satisfactory adherence to post-op micronutrient supplementation and few gestational complications following BS. Moreover, child's birth weight was not associated with maximum %WL, %WL at conception, or time since BS.

Perception of Hunger/Satiety and Nutrient Intake in Women Who Regain Weight in the Postoperative Period After Bariatric Surgery.

OBJECTIVE: To investigate the perception of hunger and satiety and its association with nutrient intake in women who regain weight in the postoperative period after bariatric surgery. METHODS: Cross-sectional study of adult women divided into three groups: weight regain (n = 20), stable weight (n = 20) (both at least 24 months after Roux-en-Y gastric bypass surgery), and non-operated obesity (n = 20). A visual analogue scale measured hunger/satiety perception while fasting, immediately after finishing a test meal, and 180 min after finishing the test meal. The incremental area above or under the curve was calculated. Food intake was analyzed by 3 days of food recall and adjusted for intraindividual variation. To make between-group comparisons, Mann-Whitney, ANOVA, Kruskal-Wallis, and independent-samples T tests and Pearson's correlation were used. RESULTS: There were no between-group differences in incremental areas of hunger/satiety, but protein intake was significantly lower among patients who regained weight compared with those who had stable body weight (0.99 ± 0.23 g/kg body weight vs. 1.17 ± 0.21 g/kg body weight, p = 0.047). In the group that regained weight, satiety was correlated positively with usual dietary protein density (r = 0.541; p = 0.017) and negatively with usual carbohydrate intake (r = - 0.663; p = 0.002). CONCLUSION: Women who regained weight presented similar perceptions of hunger/satiety to those of patients without weight regain and with non-operated obesity. In patients who regained weight postoperatively, satiety perception was correlated positively with usual dietary protein density and inversely with usual carbohydrate intake.

Effect of Protein Intake on the Protein Status and Lean Mass of Post-Bariatric Surgery Patients: a Systematic Review.

BACKGROUND: Post-bariatric surgery may compromise nutritional status due to energy and protein intake restriction. METHODS: Systematic review was performed to synthesize evidence on the amount of protein intake and its association with lean mass and serum proteins during at least 6 months following Roux-en-Y gastric bypass or sleeve gastrectomy. RESULTS: Twelve studies (n = 739) were identified in the search. Protein intake below 60 g/day and significant lean mass loss were observed in majority of these studies. Of the four studies that measured association between protein intake and lean mass retention, only two supported this hypothesis. CONCLUSION: There is insufficient evidence of the effect of dietary protein on serum protein levels. Further studies are needed to better estimate the protein intake that supports a healthy nutritional status in this population.

Diet-induced thermogenesis in postoperatve Roux-en-Y gastric bypass patients with weight regain.

BACKGROUND: Bariatric surgery has been shown to be an effective treatment for obesity. Changes in energy expenditure, especially through diet-induced thermogenesis (DIT), have been identified as one of the mechanisms to explain this success. However, not all patients are able to maintain healthy postoperative weight loss. Therefore, a question arises: In the weight regain after bariatric surgery, are these changes in energy metabolism still active? OBJECTIVE: To investigate if weight regain after Roux-en-Y gastric bypass (RYGB) surgery is associated with a lower diet-induced thermogenesis in the late postoperative period. SETTING: A cross-sectional study with the participants chosen from among the patients from a private practice. METHODS: This was a cross-sectional study where 3 groups of female patients were evaluated: (1) 20 patients with a RYGB postoperative time period of at least 2 years, who kept a healthy weight after surgery (loss of at least 50% of excess weight; Healthy group); (2) 19 patients with clinically severe obesity (BMI>40 kg/m(2), without co-morbidities and>35 kg/m(2), with co-morbidities; Pre group); (3) 18 patients who experienced weight regain after RYGB (Regain group). The 3 groups were submitted to indirect calorimetry to measure resting metabolic rate (RMR), respiratory quotient (RQ), and DIT. Immediately after the RMR measurement, a mixed meal of regular consistency was offered. Ten minutes after the food intake began, energy expenditure measurements were initiated continuing throughout the following 3 postprandial hours. Body composition was evaluated using multifrequency bioelectrical impedance. In subgroups of the studied population, glucose and insulin levels were measured at baseline and at 30, 60, 90, 120, and 180 minutes after feeding. The mean area under the curve (AUC) between the 3 groups and measurements at baseline were compared using the analysis of variance (ANOVA). RESULTS: The Healthy group had the highest weight adjusted RMR value compared with both the Pre and Regain group (23.03±3.02 kcal/kg; 16.18±2.94 kcal/kg; 17.11±3.28 kcal/kg, respectively; P<.0001). The Regain and Pre groups showed no difference for this variable. The weight-adjusted DIT (AUC 0-180 min) was about 42% and 34% higher in the Healthy group compared with the Pre and Regain groups, respectively (P<.0001). Lean body mass (kg) showed a positive correlation with the AUC of weight-adjusted DIT in the 3 groups. Multiple regression revealed that lean body mass was the only variable related to weight adjusted DIT, independent of group and other selected variables. CONCLUSION: Weight-adjusted DIT in the Regain group was smaller compared with the Healthy group, and with no difference compared with the Pre group. The lean body mass seems to have a positive association with diet-induced thermogenesis.

Effects of a very low calorie diet in the preoperative stage of bariatric surgery: a randomized trial.

BACKGROUND: Preoperative bariatric patients can follow very low calorie diets (VLCD), reducing surgical risks. However, possible advantages of a liquid diet over one of normal consistency are controversial. This study investigated the effect of a liquid VLCD compared with one of normal consistency considering visceral fat (VF) loss and metabolic profile in preoperative clinically severe obese patients. METHODS: This was a randomized, open-labeled, controlled clinical trial. Patients were divided into 2 groups: liquid diet and normal diet. Data were collected at baseline and 7 and 14 days after intervention. Information gathered was analyzed for loss of weight and VF, biochemical data, anthropometric data, and energy intake. RESULTS: Fifty-seven patients consumed the liquid diet and 47 consumed the normal consistency diet. The liquid diet group lost significantly more weight (P<.0290) and VF (P<.0410) than the normal diet group. An inverse correlation occurred between VF loss and surgical time among the liquid diet group (r2=-.1302, P=.001). Additionally, there was a positive correlation between the percentage of excess weight loss and ketonuria (P=.0070). No between-group difference occurred regarding calorie intake. CONCLUSION: Patients that consumed a liquid diet presented a positive effect on reducing VF and greater weight loss than the normal diet group. Both VLCDs presented benefits offering a protective effect during the preoperative stage.

Comparison of weight loss, food consumption and frequency of vomiting among Roux-en-Y gastric bypass patients with or without constriction ring.

BACKGROUND: After Roux-en-Y gastric bypass to avoid rapid gastric emptying, dumping syndrome and regained weight due to possible dilation of the gastric pouch, was proposed to place a ring around the gastric pouch. AIM: To compare weight loss, consumption of macronutrients and the frequency of vomiting among patients who underwent Roux-en-Y gastric bypass with and without the placement of a constriction ring around the pouch. METHOD: A retrospective study, in which an analysis of medical records was carried out, collecting data of two groups of patients: those who underwent the operation with the placement of a constriction ring (Ring Group) and those who underwent without the placement of a ring (No-Ring Group). The food intake data were analyzed using three 24-hour recalls collected randomly in postoperative nutritional accompaniment. Data on the percentage of excess weight loss and the occurrence of vomiting were collected using the weight corresponding to the most recent report at the time of data collection. RESULTS: Medical records of 60 patients were analyzed: 30 from the Ring Group (women: 80%) and 30 from the No-Ring Group (women: 87%). The average time since the Ring Group underwent the operation was 88 ± 17.50 months, and for the No-Ring Group 51 ± 15.3 months. The percentage of excess weight loss did not differ between the groups. The consumption of protein (g), protein/kg of weight, %protein and fiber (g) were higher in the No-Ring Group. The consumption of lipids (g) was statistically higher in the Ring Group. The percentage of patients who never reported any occurrence was statistically higher in the No-Ring Group (80%vs.46%). The percentage who frequently reported the occurrence was statistically higher in the Ring Group (25%vs.0%). CONCLUSION: The placement of a ring seems to have no advantages in weight loss, favoring a lower intake of protein and fiber and a higher incidence of vomiting, factors that have definite influence in the health of the bariatric patient.

Diet-induced thermogenesis and respiratory quotient after Roux-en-Y gastric bypass surgery: a prospective study.

BACKGROUND: Studies in humans and other animals have shown that Roux-en-Y gastric bypass (RYGB) leads to increased energy expenditure (EE). We analyzed several components of EE, such as the respiratory quotient (RQ), resting metabolic rate (RMR), and diet-induced thermogenesis (DIT) among patients before and after RYGB. METHODS: In this prospective clinical study, RMR, DIT, and RQ were measured by indirect calorimetry (IC) in the same patients before and 12 months after RYGB (the preoperative and postoperative time points, respectively). Postprandial RQ and DIT were measured after patients consumed a standard ~270 kcal meal (62% carbohydrates, 12% proteins, and 26% lipids). RESULTS: The population studied consisted of 13 patients (mean age 40.8 ± 6.7 years, 85% female).At the postoperative (postop) time point, patients showed higher weight-adjusted RMR compared with the preoperative (preop) time point (P<.01). The absolute and weight-adjusted metabolic rates 20 minutes after the meal were increased postoperatively (P<.0001) but not preoperatively (P = 0.2962) (DIT); this increase in RQ was significantly higher in the postop than in the preop time point. CONCLUSION: The observed patients showed increased EE, DIT, and RQ after RYGB surgery. These data may serve as important physiologic factors contributing to the loss and maintenance of weight after RYGB.

Comparison of weight loss, food consumption and frequency of vomiting among Roux-en-Y gastric bypass patients with or without constriction ring / Comparação da perda de peso, consumo alimentar e frequência de vômitos entre pacientes do bypass gástrico em Y-de-Roux com e sem colocação de anel de contenção

BACKGROUND: After Roux-en-Y gastric bypass to avoid rapid gastric emptying, dumping syndrome and regained weight due to possible dilation of the gastric pouch, was proposed to place a ring around the gastric pouch. AIM: To compare weight loss, consumption of macronutrients and the frequency of vomiting among patients who underwent Roux-en-Y gastric bypass with and without the placement of a constriction ring around the pouch. METHOD: A retrospective study, in which an analysis of medical records was carried out, collecting data of two groups of patients: those who underwent the operation with the placement of a constriction ring (Ring Group) and those who underwent without the placement of a ring (No-Ring Group). The food intake data were analyzed using three 24-hour recalls collected randomly in postoperative nutritional accompaniment. Data on the percentage of excess weight loss and the occurrence of vomiting were collected using the weight corresponding to the most recent report at the time of data collection. RESULTS: Medical records of 60 patients were analyzed: 30 from the Ring Group (women: 80%) and 30 from the No-Ring Group (women: 87%). The average time since the Ring Group underwent the operation was 88±17.50 months, and for the No-Ring Group 51±15.3 months. The percentage of excess weight loss did not differ between the groups. The consumption of protein (g), protein/kg of weight, %protein and fiber (g) were higher in the No-Ring Group. The consumption of lipids (g) was statistically higher in the Ring Group. The percentage of patients who never reported any occurrence was statistically higher in the No-Ring Group (80%vs.46%). The percentage who frequently reported the occurrence was statistically higher in the Ring Group (25%vs.0%). CONCLUSION: The placement of a ring seems to have no advantages in weight loss, favoring a lower intake of protein and fiber and a higher incidence of vomiting, factors ...

RACIONAL: Após bypass gástrico em Y-de-Roux e a fim de evitar o rápido esvaziamento gástrico, amenizar a síndrome de dumping e evitar o reganho de peso devido à possível dilatação da anastomose gastrojejunal, foi idealizada a colocação de um anel ao redor do reservatório gástrico. OBJETIVO: Comparar a perda de peso, o consumo de macronutrientes e a frequência de vômitos entre pacientes que realizaram o bypass gástrico em Y-de-Roux com e sem a colocação do anel de contenção. MÉTODOS: Estudo retrospectivo na análise de prontuários para a coleta dos dados de dois grupos de pacientes: os que realizaram o bypass gástrico em Y-de-Roux com a colocação do anel de contenção ao redor da bolsa gástrica (grupo com anel) e sem a colocação do anel (grupo sem anel). Os dados de consumo alimentar foram analisados através de três recordatórios de 24 horas coletados aleatoriamente nos atendimentos nutricionais do pós-operatório. Os dados quanto à porcentagem de perda do excesso de peso e ocorrência de vômitos foram coletados utilizando o peso e o relato mais recente em relação ao período da coleta. RESULTADOS: Analisaram-se prontuários de 60 pacientes: 30 do grupo com anel e 30 do grupo sem anel. A média do tempo de operado do grupo com anel foi de 88±17,5 meses, e do grupo sem anel 51±15,3 meses. A porcentagem de perda do excesso de peso não diferiu entre os grupos. O consumo de proteína (g), proteína/kg de peso, %proteína e fibras (g) foi estatisticamente superior no grupo sem anel. O consumo de lipídios (g) foi estatisticamente superior no grupo com anel. A porcentagem de pacientes que nunca relataram a ocorrência foi estatisticamente superior no grupo sem anel (80%vs46%). A porcentagem ...

Validation of ultrasound examination for assessment of the abdominal visceral fat in clinically serious obese patient.

BACKGROUND: Computerized tomography is the gold-standard for measurement of abdominal visceral fat. However, it is costly and involves submitting patients to ionizing radiation. AIM: To validate the use of ultrasonography in assessing abdominal visceral fat among clinically serious obese patients of both genders. METHODS: The sample included adult patients with clinically serious obesity with body mass index of 40 kg/m2 or from 35 kg/m(2) to 40 kg/m2 with co-morbidities. Abdominal visceral fat thickness was measured using ultrasound and tomography. Two ultrasonographic exams were conducted to assess the interobserver reproducibility among a patient subsample. Validation was done by comparing these results with the tomographic findings. RESULTS: The study included 13 patients (61.54% female) with an average BMI of 38.82 kg/m2. In terms of validation, the result obtained from applying the Pearson correlation coefficient was equal to 0.94 (p = 0.0005), showing a strong positive correlation between the two measurements. As for the results for reproducibility, the interobserver was equal to 0.822, with a confidence interval of 95% (-0.076 to 0.980), revealing good interobserver agreement. The average difference between the two ultrasound interobserver examination was equal to 0.10 ± 1.51 (p=0.8898) and so not significant. Interobserver bias was also not significant. CONCLUSION: The validation of ultrasonographic examination to replace tomographic method in assessing abdominal visceral fat among clinically serious obese patients was effective. The ultrasound measurement is independent of the examiner.

Validação da ultrassonografia para a avaliação da gordura abdominal visceral em obesos clinicamente graves / Validation of ultrasound examination for assessment of the abdominal visceral fat in clinically serious obese patient

RACIONAL: A tomografia computadorizada é o padrão-ouro para a medida da gordura abdominal visceral. No entanto é dispendiosa e envolve submeter os doentes à radiação ionizante. OBJETIVO: Validar o método ultrassonográfico para avaliação da gordura abdominal visceral em obesos clinicamente graves de ambos os sexos. MÉTODOS: A amostra incluiu adultos com obesidade clinicamente grave que apresentavam índice de massa corporal de 40kg/m² ou entre 35kg/m² e 40kg/m² com comorbidades associadas. Os exames realizados para medição da espessura da gordura visceral foram: ultrassonografia e de tomografia computadorizada. Foram realizados dois exames para avaliação da reprodutibilidade interobservador em uma subamostra de pacientes. O estudo ultrassonográfico foi validado comparando-o aos resultados do exame tomográfico. RESULTADOS: Participaram do estudo 13 pacientes, sendo 61,54% mulheres com IMC médio de 38,82kg/m². A validação foi feita pelo coeficiente de correlação de Pearson resultando ser igual a 0,94 (p = 0,0005). Evidenciou-se correlação positiva e forte entre as duas medidas. Quanto aos resultados da reprodutibilidade, o coeficiente de correlação intraclasse interobservador foi igual a 0,822 com intervalo de confiança de 95% (-0,076 a 0,980), o que revela boa concordância interobservador. A diferença média entre os dois observadores na ultrassonografia foi igual a 0,10 ± 1,51 (p = 0,8898), não significativa e sem viés significativo interobservador. CONCLUSÃO: Foi efetiva a validação do exame ultrassonográfico como substituição ao tomográfico para avaliar a gordura abdominal visceral entre obesos clinicamente graves. A medida ultrassonográfica independe do examinador.

BACKGROUND: Computerized tomography is the gold-standard for measurement of abdominal visceral fat. However, it is costly and involves submitting patients to ionizing radiation. AIM: To validate the use of ultrasonography in assessing abdominal visceral fat among clinically serious obese patients of both genders. METHODS: The sample included adult patients with clinically serious obesity with body mass index of 40kg/m2 or from 35kg/m2 to 40kg/m2 with co-morbidities. Abdominal visceral fat thickness was measured using ultrasound and tomography. Two ultrasonographic exams were conducted to assess the interobserver reproducibility among a patient subsample. Validation was done by comparing these results with the tomographic findings. RESULTS: The study included 13 patients (61.54% female) with an average BMI of 38.82 kg/m2. In terms of validation, the result obtained from applying the Pearson correlation coefficient was equal to 0.94 (p = 0.0005), showing a strong positive correlation between the two measurements. As for the results for reproducibility, the interobserver was equal to 0.822, with a confidence interval of 95% (-0.076 to 0.980), revealing good interobserver agreement. The average difference between the two ultrasound interobserver examination was equal to 0.10 ± 1.51 (p=0.8898) and so not significant. Interobserver bias was also not significant. CONCLUSION: The validation of ultrasonographic examination to replace tomographic method in assessing abdominal visceral fat among clinically serious obese patients was effective. The ultrasound measurement is independent of the examiner.

Diet-induced thermogenesis and respiratory quotient after Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) surgery is an effective tool for long-term weight loss. Mechanisms underlying the effectiveness of such surgery might result not only from the anatomic changes due to the procedure, but also from favorable changes in energy metabolism. Our objective was to evaluate the respiratory quotient (RQ), resting metabolic rate (RMR), and diet-induced thermogenesis (DIT) among clinically severe obese patients (control group) and patients who had undergone RYGB ≥ 1 year previously. The setting was Gastrocirurgia de Brasilia (Brasilia, Brazil). METHODS: The present study was cross-sectional and involved 35 clinically severe obese patients (body mass index ≥ 40 kg/m(2) or body mass index ≥ 35 kg/m(2) with co-morbidities) as the control group and 34 RYGB patients who had undergone the procedure ≥ 12 months previously (RYGB group). The anthropometric data (height and weight) were determined for both groups, and the RMR and RQ were measured using indirect calorimetry after a 12-hour fast. Patients then received a standard meal, and DIT was determined. The RMR and DIT were also adjusted per kilogram of body weight (BW), i.e BW-adjusted RMR and BW-adjusted DI. RESULTS: The BW-adjusted RMR and RQ did not differ between the 2 groups in the fasting period. However, the DIT of the RYGB group, whether absolute or BW-adjusted, was >200% that of the control group (P <.0001). The BW-adjusted DIT of the RYGB group correlated significantly with the percentage of excess weight loss (P = .0097). The postprandial RQ value among the RYGB group was also significantly (P <.0001) greater than that of the control group, suggesting an increased use of carbohydrates. CONCLUSION: Postprandial changes in energy expenditure and fuel use might contribute, in part, to the effectiveness of weight loss as a result of the RYGB procedure.

Energy expenditure before and after Roux-en-Y gastric bypass.

BACKGROUND: Weight loss may decrease the energy expenditure (EE) because of changes in body composition (BC). The reduction in EE may contribute, in part, to weight regain. Experimental studies in animals indicate that Roux-en-Y Gastric Bypass (RYGB) increases the resting metabolic rate (RMR) when adjusted for body weight (BW). Thus, the aim of this study was to assess the clinical effects of RYGB on EE in patients who have undergone RYGB. METHODS: The study was prospective and included 46 RYGB patients whose RMR was assessed prior to and at least 6 months post-surgery by indirect calorimetry. BW and BC were measured at these same time points using bioelectric impedance. RMR was adjusted for changes in BW, i.e., kilocalories per kilogram. Statistical tests were used to analyze the results. RESULTS: The BW-adjusted RMR (kilocalories per kilogram) increased post-RYGB by 17.66 % (p < 0.0001). RMR adjusted for BW was negatively correlated to the total percentage of body fat preoperatively (r = -0.30729, p = 0.0378) and postoperatively (r = -0.46731, p = 0.0011) and was positively correlated to the fat-free mass percentage (%FFM) both preoperatively and postoperatively. Furthermore, BW-adjusted RMR and %FFM were positively correlated to percent excess weight loss (r = 0.55398, p < 0.0001 and r = 0.31677, p = 0.0283, respectively). CONCLUSIONS: Weight loss following RYGB is associated with an increase in BW-adjusted RMR and with %FFM. An increase in energy expenditure post-RYGB may be responsible, in part, for successful long-term weight loss of the RYGB procedure.

Metabolic profile of clinically severe obese patients.

BACKGROUND: Since low basal metabolic rate (BMR) is a risk factor for weight regain, it is important to measure BMR before bariatric surgery. We aimed to evaluate the BMR among clinically severe obese patients preoperatively. We compared it with that of the control group, with predictive formulas and correlated it with body composition. METHODS: We used indirect calorimetry (IC) to collect BMR data and multifrequency bioelectrical impedance to collect body composition data. Our sample population consisted of 193 patients of whom 130 were clinically severe obese and 63 were normal/overweight individuals. BMR results were compared with the following predictive formulas: Harris-Benedict (HBE), Bobbioni-Harsch (BH), Cunningham (CUN), Mifflin-St. Jeor (MSJE), and Horie-Waitzberg & Gonzalez (HW & G). This study was approved by the Ethics Committee for Research of the University of Brasilia. Statistical analysis was used to compare and correlate variables. RESULTS: Clinically severe obese patients had higher absolute BMR values and lower adjusted BMR values (p < 0.0001). A positive correlation between fat-free mass and a negative correlation between body fat percentage and BMR were found in both groups. Among the clinically severe obese patients, the formulas of HW & G and HBE overestimated BMR values (p = 0.0002 and p = 0.0193, respectively), while the BH and CUN underestimated this value; only the MSJE formulas showed similar results to those of IC. CONCLUSIONS: The clinically severe obese patients showed low BMR levels when adjusted per kilogram per body weight. Body composition may influence BMR. The use of the MSJE formula may be helpful in those cases where it is impossible to use IC.

Dietary protein intake and bariatric surgery patients: a review.

Bariatric surgery, a highly successful treatment for obesity, requires adherence to special dietary recommendations to insure the achievement of weight loss goals and weight maintenance. Postoperative consumption of protein is linked to satiety induction, nutritional status, and weight loss. Hence, we conducted an extensive literature review to identify studies focused on the following: protein and nutritional status; recommendations for dietary protein intake; the effects of protein-rich diets; and associations between dietary protein intake and satiety, weight loss, and body composition. We found that there have been few studies on protein intake recommendations for bariatric patients. Dietary protein ingestion among this population tends to be inadequate, potentially leading to a loss of lean body mass, reduced metabolic rates, and physiological damage. Conversely, a protein-rich diet can lead to increased satiety, enhanced weight loss, and improved body composition. The quality and composition of protein sources are also very important, particularly with respect to the quantity of leucine, which helps to maintain muscle mass, and thus is particularly important for this patient group. Randomized studies among bariatric surgery patient populations are necessary to establish the exact quantity of protein that should be prescribed to maintain their nutritional status.