Protocol.

<p>Patients arrived at 07.30 after an 11 hour fast. The patients spent 25 hours in total in the chamber for indirect calorimetry.</p

Energy expenditure and respiratory quotient.

<p>Energy expenditure and respiratory quotient for gastric bypass (n = 7) and VBG patients (n = 7) 9.4 years after surgery.</p><p>Energy expenditure are analyzed s cal/min/kg total tissue. 24 hour values for GBP and VBG patients were calculated after the 165 minutes post physical activity was excluded. Values are mean (confidence interval).</p

Biochemical variables.

<p>Biochemical variables in gastric bypass (n = 7) and VBG (n = 7) patients. Area under the curve (AUC) values of GLP-1 and PYY were calculated using fasting and following a standard 400 kcal meal samples over a 150 minutes period where samples were obtained every 30 minutes. Values are mean (confidence interval).</p

Demographics and body composition.

<p>Demographics and body composition in gastric bypass (n = 7) and VBG (n = 7) patients before and 9.4 years after surgery. Values are mean (confidence interval).</p

Energy expenditure during dinner intake.

<p>Mean energy expenditure (cal⋅min-¹⋅kg-¹) one hour before dinner and two hours after dinner started. The duration of the meal is also shown as median and range.</p

Biliopancreatic Diversion is associated with greater increases in energy expenditure than Roux-en-Y Gastric Bypass

<div><p>Objective</p><p>The greater weight loss achieved following Biliopancreatic Diversion with Duodenal Switch (BPDS) versus Roux-en-Y Gastric Bypass (RYGB) has been attributed to the malabsorptive effects of BPDS. Increased weight loss after BPDS could also be underpinned by larger increases in energy expenditure. Hypothetically, the more radical reconfiguration of the small intestine in BPDS could result in an accentuated increase in meal associated thermogenesis (MAT).</p><p>Design</p><p>Female subjects (baseline mean age 40 years, mean BMI-55kg/m²) were assessed four years after randomization to BPDS (n = 6) or RYGB (n = 6). Energy expenditure (EE) and respiratory quotient (RQ) were measured by indirect calorimetry over 24 hours. A detailed protocol allowed for discrimination of basal metabolic rate (BMR), fasting EE and MAT as components of total energy expenditure (TEE) normalised for total and lean tissue by dual-energy x-ray absorptiometry.</p><p>Results</p><p>Median weight loss at follow-up was 1.5-fold higher following BPDS relative to RYGB, resulting in respective median BMIs of 29.5 kg/m² (21.7 to 36.7) after BPDS and 37.8 kg/m² (34.1 to 45.7) after RYGB (p = 0.015). The BPDS group had a lower fat:lean ratio compared to the RYGB group (p = 0.009). Overall 24-hour TEE adjusted for total tissue was higher in the BPDS group, as were BMR, fasting EE and MAT (all p<0.05). Differences between RYGB and BPDS in BMR and TEE were nullified when normalised for lean mass. Postprandial RQ increased significantly but to a similar extent in both groups.</p><p>Conclusion</p><p>Enhanced and prolonged MAT and lower fat:lean mass ratios after BPDS may explain relative increases in total energy expenditure as compared to RYGB.</p></div

Six female subjects assessed for energy expenditure during one hour after a 600 kcal standard meal; from 18:20 to 19:20.

<p>Assessments were performed before, visit 1, and at weight stability 20 months after, visit 4, gastric bypass surgery. Data are presented as mean values in kcal/minute and as percentage of total energy expenditure.</p

Time after surgery & weight loss.

<p>Time after surgery & weight loss.</p

Time after surgery & weight loss.

<p>Time after surgery & weight loss.</p

Protocol during study visits before as well as 10 days, 3 months and 20 months after gastric bypass surgery for six female study subjects.

<p>Protocol during study visits before as well as 10 days, 3 months and 20 months after gastric bypass surgery for six female study subjects.</p