Orlando Pereira Faria

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.

Snack-eating patients experience lesser weight loss after Roux-en-Y gastric bypass surgery.

BackgroundIn bariatric surgery patients, weight loss and long-term weight maintenance are related to food intake and eating patterns. To improve the diet orientation in the bariatric surgery postoperative period, we assessed the postoperative eating patterns and related them to weight loss.MethodsThis was a transversal, analytical, and descriptive study that assessed body mass index (BMI) values and percentage of excess weight loss (%EWL) in patients who had undergone Roux-en-Y gastric bypass (RYGBP) surgery. The eating pattern and energy intake were investigated based on data collected through a 4-day food intake record. From these records, we assessed the number of daily meals, the quantity of food per meal, and calorie value of snacks between main meals. Based on these records, patients were classified under sweet-eating, snack-eating, or normal-eating patterns.ResultsSeventy-five patients met our inclusion criteria. The normal-eating pattern group was the one with the greatest weight loss with an average %EWL of 71.4 ± 21%, followed by the sweet-eating pattern with 69.9 ± 16.8%, and the snack-eating pattern with 56.4 ± 16.7%. This difference was significant only between the first and the third group (p = 0.04). The snack-eating patients had the highest caloric intake and highest number of daily meals (p < 0.01).ConclusionPostoperative eating pattern influenced postbariatric surgery weight loss. In the present study, the snack-eating pattern was associated with the worst weight loss outcome, followed by the sweet-eating and normal-eating patterns. A screening and a differential approach to patients according to their eating patterns may lead to better results of weight loss.

Relation Between Carbohydrate Intake and Weight Loss After Bariatric Surgery

BackgroundWeight loss and long-term weight maintenance in bariatric surgery patients are related to maintaining satiety. It can be related to glycemic load (GL) and carbohydrate (g CHO) intake. The aim of this study was to investigate the effect of g CHO and GL and in weight loss on patients who had undergone bariatric surgery.MethodThe following measurements/calculations were conducted as follows: current body weight (kg), current BMI, percentage of excess weight loss (PEWL), average monthly weight loss (AMWL), energy intake (kcal per day), and GL calculation. Correlations were found among the studied variables. A multiple linear regression analysis of diet variables executed with GL and weight loss.ResultsThe population presented 66% of EWL. The average of total energy intake (TEI) was 1220 ± 480, and the calculated GL resulted in an average of 73.2. Negative correlations were found between AMWL and TEI (p = 0.04), and between AMWL and GL (p = 0.009); furthermore, a negative correlation was found between carbohydrate intake in grams and AMWL (p = 0.003). A positive correlation (p = 0.017) was found between GL and TEI. Weight loss and GL were also correlated. Among the intake variables, GL and g CHO consumed are held accountable for 62 percent of AMWL. The multiple linear regression analysis showed that GL and carbohydrate grams (g CHO) account for 62% of AMWL.ConclusionThe glycemic load and grams of carbohydrate are intake factors that can be useful tools in weight loss and long-term weight maintenance on patients who have undergone Roux-en-Y Gastric Bypass (RYGB).

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.

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.

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.

Metabolic Profile of Clinically Severe Obese Patients

BackgroundSince 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.MethodsWe 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.ResultsClinically 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.ConclusionsThe 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.

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.

Validação da ultrassonografia para a avaliação da gordura abdominal visceral em obesos clinicamente graves

RACIONAL: A tomografia computadorizada e o padrao-ouro para a medida da gordura abdominal visceral. No entanto e dispendiosa e envolve submeter os doentes a radiacao ionizante. OBJETIVO: Validar o metodo ultrassonografico para avaliacao da gordura abdominal visceral em obesos clinicamente graves de ambos os sexos. METODOS: A amostra incluiu adultos com obesidade clinicamente grave que apresentavam indice de massa corporal de 40kg/m2 ou entre 35kg/m2 e 40kg/m2 com comorbidades associadas. Os exames realizados para medicao da espessura da gordura visceral foram: ultrassonografia e de tomografia computadorizada. Foram realizados dois exames para avaliacao da reprodutibilidade interobservador em uma subamostra de pacientes. O estudo ultrassonografico foi validado comparando-o aos resultados do exame tomografico. RESULTADOS: Participaram do estudo 13 pacientes, sendo 61,54% mulheres com IMC medio de 38,82kg/m2. A validacao foi feita pelo coeficiente de correlacao de Pearson resultando ser igual a 0,94 (p = 0,0005). Evidenciou-se correlacao positiva e forte entre as duas medidas. Quanto aos resultados da reprodutibilidade, o coeficiente de correlacao intraclasse interobservador foi igual a 0,822 com intervalo de confianca de 95% (-0,076 a 0,980), o que revela boa concordância interobservador. A diferenca media entre os dois observadores na ultrassonografia foi igual a 0,10 ± 1,51 (p = 0,8898), nao significativa e sem vies significativo interobservador. CONCLUSAO: Foi efetiva a validacao do exame ultrassonografico como substituicao ao tomografico para avaliar a gordura abdominal visceral entre obesos clinicamente graves. A medida ultrassonografica independe do examinador.

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.