The effect of additional protein on lean body mass preservation in post-bariatric surgery patients: a systematic review.

BACKGROUND: As result of bariatric surgery, patients are susceptible to protein deficiency which can result in undesirable lean body mass (LBM) loss. Consumption of high-protein diets or supplements could counteract this, but evidence about the effect is scarce. This paper systematically reviewed the literature to determine the effect of additional protein intake (≥60 g/day) on LBM preservation in post-bariatric patients. METHODS: An electronic search of PubMed, EMBASE and the Cochrane Library was conducted. Studies were included if patients received a high-protein diet or protein supplements for at least one month, and LBM was assessed. The primary outcome was difference in mean LBM loss between the experimental (protein) and control group. Secondary outcomes were differences in body fat mass, total body water, body mass index and resting metabolic rate. RESULTS: Two of the five included studies (n = 223) showed that consumption of proteins resulted in significant LBM preservation. Only one study reported a significant difference in the reduction of body fat mass and resting metabolic rate in favour of a high-protein diet, but none of the studies showed a significant difference in total body water loss or body mass index change between the two groups. CONCLUSIONS: This paper showed inconclusive evidence for LBM preservation due to protein supplementation or a high-protein diet in post-bariatric patients. This outcome might be subjected to certain limitations, including a lack of blinding and a low compliance rate reported in the included studies. More specific and personalized recommendations regarding protein intake may need to be established by high quality research. Studies investigating the quantity (g/day) and quality (whey, casein or soy) of proteins are also needed.

Roux-en-Y Gastric Bypass Versus Sleeve Gastrectomy in Young Adults: a Dutch Registry Study.

BACKGROUND: The most commonly performed bariatric procedures worldwide are Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), yet outcomes following these procedures in young adults are limited. Therefore, the objective of this study was to compare weight loss outcomes between RYGB and SG in young adults. METHODS: This is a nationwide retrospective cohort study of young adults, aged 18-25 years, who underwent RYGB or SG between 2015 and 2019, with data from the Dutch Audit Treatment of Obesity (DATO). The primary outcome was weight loss expressed as percentage total weight loss (%TWL) in a period of 3 years after surgery. Secondary outcomes were the incidence of complications (< 30 days) and progression of obesity-related comorbidities. RESULTS: In total, 2313 patients were included, 1246 in the RYGB group and 1067 in the SG group. Percentage TWL was significantly higher in the RYGB group compared to the SG group at 1, 2, and 3 years after surgery (respectively 2.4%, 2.9%, and 3.3% higher, p < 0.001). RYGB was associated with an on-average 2.75 higher %TWL compared to SG in females (p < 0.001), although this was not seen in males (ß = 0.63, p = 0.514). No differences were found in the incidence of complications, nor the progression of obesity-related comorbidities except for gastroesophageal reflux disease (GERD). There was more improvement or resolution of GERD in the RYGB group (95.2% vs. 56.3%, p < 0.001). CONCLUSION: Similar numbers of RYGB and SG were performed in young adults, whereas RYGB was associated with greater weight loss in the short- and midterm, particularly in females.

Emotional eating as predictor of weight loss 2 years after Roux-en-Y gastric bypass.

There has been little agreement on the predictive value of emotional eating on weight loss outcomes after bariatric surgery. The aim of this study was to examine the predictive value of preoperative emotional eating, in response to clearly labelled emotions and diffuse emotions, on excess weight loss (EWL) and total weight loss (TWL) 2 years after Roux-en-Y gastric bypass (RYGB). All participants included in this retrospective cohort study were screened for RYGB surgery by a multidisciplinary team. The level of emotional eating was derived from the Dutch Eating Behaviour Questionnaire (DEBQ); the level of psychological variables from the Symptom Checklist-90. Participants were clustered, based on their DEBQ score, in high and low emotional eaters. Multiple linear regression analyses were performed to examine the association between preoperative emotional eating and EWL, and TWL. There were no significant differences in EWL of the 172 included participants, defined as either high or low emotional eaters (EWL 82.7% ±18.2 versus 82.4% ±21.3, respectively). Based on the regression analysis, emotional eating was not significantly associated with EWL, nor with TWL. When corrected for psychological, demographic and biological variables, preoperative emotional eating in response to diffuse emotions negatively affected EWL (ß = -0.16, P = 0.048), although this was not applicable for TWL. Preoperative emotional eating does not seem to influence EWL, nor TWL 2 years after RYGB. Since this study faced multiple limitations, further investigation is required regarding the predictive value of emotional eating.

Place Work on a Scale: What Do We Know About the Association Between Employment Status and Weight Loss Outcomes After Bariatric Surgery?

Despite the initial successful weight loss after bariatric surgery, a significant amount of patients experience weight loss failure and weight regain. Several factors are known to contribute to this, though the impact of employment status is unknown. The objective of this systematic review was to examine the impact of employment status on post-surgical weight loss outcomes. Eight studies were included with a follow-up ranging between 2 and 10 years. Employed patients seemed to present more weight loss (9.0-11.0% EWL, 1.3-1.6% BMI loss) compared to unemployed patients, but none of these numbers were statistically significant. Moreover, there were contrasting findings in terms of weight regain. This review may highlight the importance of working status after bariatric surgery and warrants further investigation on this topic.

Current preoperative strategies applied in the Dutch bariatric centers: A national survey.

There is no consensus about the optimal management of patients undergoing bariatric surgery. This study aimed to identify current weight loss goals prior to bariatric surgery, as well as aimed to explore preoperative strategies related to diet, nutritional supplements and physical activity. An online survey was distributed among bariatric surgeons and dietitians in all 18 Dutch bariatric centers. This survey included the following four domains: weight loss, diet, nutritional supplements and physical activity. For the analyses one answer per center was used, either the most common answer or the answer given by the most expert responder. All 18 centers reported at least one response. Preoperative weight loss was requested in 28% of the centers, whereas 61% desired a stable weight or weight loss, and 11% had no requests. A preoperative diet was routinely recommended in 78% of the centers and on indication (ie, depending on baseline weight and/or comorbidity status) in 22%. The most frequently prescribed diet was a low-energy diet (800-1500 kcal/day) in 44% of the centers. Nutritional supplements were recommended in 78% of the centers. Physical activity with low intensity was recommended in 83% of the centers, while physical exercise training with mid- to high-intensity was recommended in 72%. Inconsistent responses within centers were observed in 56% of the questions. The current bariatric practice within the Netherlands shows high variability and inconsistencies in preoperative management. Consensus-building and standardization of strategies should be promoted in the future.

Effectiveness of a Low-Calorie Diet for Liver Volume Reduction Prior to Bariatric Surgery: a Systematic Review.

An energy-restricted diet is often prescribed before bariatric surgery to reduce weight and liver volume. While very-low-calorie diets (VLCDs, 450-800 kcal per day) have shown to be effective, the effectiveness of low-calorie diets (LCDs, 800-1500 kcal per day) is less obvious. The objective of this systematic review was to elucidate the effectiveness of LCD on liver volume reduction in patients awaiting bariatric surgery. Eight studies (n = 251) were included describing nine different diets (800-1200 kcal, 2-8 weeks). An LCD was effective in liver volume reduction (12-27%) and weight loss (4-17%), particularly during the first weeks. The LCD showed an acceptable patients' compliance. Based on these findings, an LCD (800-1200 kcal), instead of a VLCD, for 2 to 4 weeks should be preferred.

Comparison of Linear versus Circular-Stapled Gastroenterostomy in Roux-en-Y Gastric Bypass: A Nationwide Population-Based Cohort Study.

BACKGROUND: When performing a Roux-en-Y gastric bypass (RYGB), the gastroenterostomy can be constructed with a circular stapled or linear stapled technique. The size of the gastroenterostomy depends on the stapling method and this may affect weight loss outcomes. The aim of this study was to examine the impact of the stapling technique on weight loss outcomes after RYGB. METHODS: This is a nationwide population-based cohort study of patients that received a RYGB. Data were derived from the Dutch Audit of Treatment of Obesity. Primary outcome was the impact of stapling technique on the rate of non-response defined as significant weight regain (≥20% of a patients' lost weight) 2-4 years post-surgery, after initial successful weight loss (≥20% total weight loss, TWL). Secondary outcomes were the rate of response, defined as successful weight loss (≥20% TWL) within 1.5 years post-surgery, the incidence of complications and the progression of comorbidities. RESULTS: In a cohort of 12,468 patients, non-response was equally distributed between both groups (circular 18.0% vs. linear 17.6%). No differences in response rate (circular 97.0% vs. linear 96.5%) or %TWL were observed up to 4 years post-surgery. Patients in the circular stapled group experienced more complications, specifically major bleedings (2.4% vs. 1.2%; p=0.002) within 30 days postoperatively. No differences were found in deteriorated comorbidities, neither in de novo developed comorbidities. CONCLUSION: When comparing stapling technique in RYGB, weight loss outcomes did not differ during a 4-year follow-up period. The linear stapled gastroenterostomy could pose an advantage due to its lower complication rate.

Primary and Secondary Nonresponse Following Bariatric Surgery: a Survey Study in Current Bariatric Practice in the Netherlands and Belgium.

PURPOSE: Primary nonresponse (1NR) - inability to achieve adequate weight loss after surgery - and secondary nonresponse (2NR) - excessive weight regain after initial adequate weight loss after surgery - can occur in up to 25-35% of patients after bariatric surgery. The aim of this study was to explore the variations in both definition as well as management of 1NR and 2NR amongst bariatric surgeons. MATERIALS AND METHODS: An online survey was distributed to all members of the national bariatric societies in the Netherlands and Belgium regarding questions about definition, work-up and treatment of 1NR and 2NR after bariatric surgery. RESULTS: A total of 45 responses from bariatric surgeons were obtained, representing 32 medical centers that perform bariatric procedures. When assessing 1NR, excess weight loss(EWL) was reported to be used by most respondents(30/45), total body weight loss(TBWL) by 18/45 and body mass index(BMI) by 25/45. A great variation in cut off values was observed. When assessing 2NR, percentage weight gain from the lowest (nadir) weight was preferred most by 22/45 respondents with cut off values varying from 5 to 20%. Most respondents deemed 18 months after initial surgery the most appropriate timeframe to determine 1NR or 2NR. CONCLUSIONS: The current practice regarding primary and secondary nonresponse after bariatric surgery has a wide variety in definitions, work-up and treatment options. Consensus on the definition of 1NR and 2NR is needed to optimize the treatment of bariatric patients.

Diet-Induced Alteration of Microbiota and Development of Obesity, Nonalcoholic Fatty Liver Disease, and Diabetes: Study Protocol of a Prospective Study.

BACKGROUND: Development of obesity and obesity-related diseases, such as type 2 diabetes mellitus and nonalcoholic fatty liver disease (NAFLD), is associated with altered gut microbiota composition. The aim of this study is to investigate associations among dietary compounds, intestinal cell function, and gut microbiota composition. We hypothesize that dietary lipid intake is associated with Paneth cell and goblet cell properties that affect gut microbiota composition. OBJECTIVE: The primary objective of this study is to determine whether a difference in dietary intake is associated with a difference in intestinal mucin-2 expression and gut microbiota composition. METHODS: This is a single-center prospective study, including 1 obese group undergoing laparoscopic Roux-en-y gastric bypass and 2 lean control groups undergoing either laparoscopic cholecystectomy or upper gastrointestinal endoscopy (n=228). During laparoscopy, biopsies will be taken of visceral fat (omentum majus), liver, muscle tissue of the abdominal wall, and subcutaneous fat. In the obese group, a small segment of the jejunum will be collected for analysis, which will be compared with an endoscopically derived jejunal biopsy from the upper gastrointestinal endoscopy control group. Stool samples for microbiota profiling will be collected at baseline and 1 year after surgery. Primary outcomes are fecal microbiota composition and mucus characteristics. Secondary outcomes include Paneth cell phenotype, body weight, diet composition, glucose tolerance, resolution of comorbidities, and weight loss 1 year after surgery. RESULTS: This trial is currently open for recruitment. The anticipated completion date is December 2019. CONCLUSIONS: The Diet-Induced Alteration of Microbiota and Development of Obesity, NAFLD, and Diabetes study will improve insight into the pathophysiology of obesity and its associated metabolic disorders. Better understanding of weight loss failure and weight regain following bariatric surgery might also behold new therapeutic opportunities for obesity and obesity-related comorbidities. TRIAL REGISTRATION: Netherlands Trial Register NTR5660; https://www.trialregister.nl/trial/5540 (Archived by WebCite at http://www.webcitation.org/78l7jOZre). INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/11553.