Is the Roux Limb a Determinant for Meal Size After Gastric Bypass Surgery?

The Roux-Y gastric bypass (RYGBP) is an effective weight-reducing procedure but the involved mechanisms of action are obscure. The Roux limb is the intestinal segment that following surgery is the primary recipient for food intake. The aims of the study were to explore the mechanosensory and biomechanical properties of the Roux limb and to make correlations with preferred meal size. Ten patients participated and were examined preoperatively, 6 weeks and 1 year after RYGBP. Each subject ingested unrestricted amounts of a standardized meal and the weight of the meal was recorded. On another study day, the Roux limb was subjected to gradual distension by the use of an intraluminal balloon. Luminal volume–pressure relationships and thresholds for induction of sensations were monitored. At 6 weeks and 1 year post surgery, the subjects had reduced their meal sizes by 62% and 41% (medians), respectively, compared to preoperative values. The thresholds for eliciting distension-induced sensations were strongly and negatively correlated to the preferred meal size. Intraluminal pressure during Roux limb distension, both at low and high balloon volumes, correlated negatively to the size of the meal that the patients had chosen to eat. The results suggest that the Roux limb is an important determinant for regulating food intake after Roux-Y bypass bariatric surgery

Decreased energy density and changes in food selection following Roux-en-Y gastric bypass

Background/Objectives:The main objective was to test the hypothesis that dietary energy density (DED) decreases after Roux-en-Y gastric bypass (gastric bypass).Subjects/Methods:A total of 43 patients (31 women and 12 men) aged 43 (s.d. 10) years, with body mass index (BMI) 44.3 kg/m 2 (4.9), were assessed preoperatively at 6 weeks and 1 and 2 years after gastric bypass. Self-reported energy intake (EI), food weight (FW) and food choice were assessed using a dietary questionnaire. DED was calculated by dividing EI by FW (kcal/g). Number of dropouts was 4 of 203 visits.Results:Percent weight loss (%WL) was 13.5% at 6 weeks, 30.7% at 1 year and 31.8% at 2 years post surgery (P\u3c0.001 for all). EI decreased from 2990 to 1774, 2131 and 2425 kcal after 6 weeks and 1 and 2 years postoperatively, respectively (P\u3c0.001 at all time points). FW changed from 2844 to 1870 g/day at 6 weeks (P\u3c0.001) and 2416 g/day after 1 year (P\u3c0.05), but was not significantly different from baseline 2 years postoperatively (2602 g/day, P=0.105). DED decreased from 1.07 to 0.78 kcal/g at 6 weeks (P\u3c0.001) and 0.90 kcal/g (P\u3c0.001) and 0.96 kcal/g (P=0.001) after 1 and 2 years, respectively. All statistical comparisons were made from baseline. There was no correlation between changes in DED and %WL, neither after 1 year (r=-0.215; P=0.183) nor after 2 years (r=-0.046; P=0.775) post surgery.Conclusions:Besides substantial reduction in EI and large variation in FW, patients reported decreased DED over 2 years following gastric bypass. Despite lack of association between the reduction in DED and percentage weight loss, changes in food choice were overall nutritionally beneficial. © 2013 Macmillan Publishers Limited All rights reserved

Two-year outcome of laparoscopic Roux-en-Y gastric bypass in adolescents with severe obesity: results from a Swedish Nationwide Study (AMOS)

CONTEXT: The prevalence of obesity among adolescents has increased and we lack effective treatments. OBJECTIVE: To determine if gastric bypass is safe and effective for an unselected cohort of adolescents with morbid obesity in specialized health care. DESIGN, SETTING AND PATIENTS: Intervention study for 81 adolescents (13-18 years) with a body mass index (BMI) range 36-69 kg m(-2) undergoing laparoscopic gastric bypass surgery in a university hospital setting in Sweden between April 2006 and May 2009. For weight change comparisons, we identified an adult group undergoing gastric bypass surgery (n = 81) and an adolescent group (n = 81) receiving conventional care. MAIN OUTCOME MEASUREMENTS: Two-year outcome regarding BMI in all groups, and metabolic risk factors and quality of life in the adolescent surgery group. RESULTS: Two-year follow-up rate was 100% in both surgery groups and 73% in the adolescent comparison group. In adolescents undergoing surgery, BMI was 45.5 +/- 6.1 (mean +/- s.d.) at baseline and 30.2 (confidence interval 29.1-31.3) after 2 years (P20 m Ul(-1)) was present in 70% of the adolescent surgery patients, which was reduced to 0% at 1 year and 3% at 2 years. Other cardiovascular risk factors were also improved. Two-thirds of adolescents undergoing surgery had a history of psychopathology. Nevertheless, the treatment was generally well tolerated and, overall, quality of life increased significantly. Adverse events were seen in 33% of patients. CONCLUSIONS: Adolescents with severe obesity demonstrated similar weight loss as adults following gastric bypass surgery yet demonstrating high prevalence of psychopathology at baseline. There were associated benefits for health and quality of life. Surgical and psychological challenges during follow-up require careful attention. International Journal of Obesity (2012) 36, 1388-1395; doi:10.1038/ijo.2012.160; published online 25 September 201