2.5.2. Duodenal Infusion
bloating, nausea,, pain
Aversive conditioning (2nd study day in aversive conditioning group only) was produced by infusion of lipids (300 mg/mL purified soybean oil; Intralipid, Fresenius Kabi, Barcelona, Spain) into the duodenum via the nasoduodenal catheter. Lipids were continuously infused starting 3 min before, during and 60 min after ingestion of the probe meal (total infusion time = 75 min) using an infusion pump (Compat Ella Push, Nestle Health Science, Barcelona, Spain) at a rate of 150 mL/h during the first 15 min (3 min pre-ingestion period and 12 min ingestion period) and at 30 mL/h during the 60 min postprandial period (The aversive conditioning procedure (lipid load and delivery rate) was established by a series of preliminary studies in 3 additional participants so that the lipid infusion would induce a negative sensation of digestive well-being (below score −2 on a −5 to +5 scale, see below) without severe nausea, bloating or pain (score ≤ 2 on 0–10 scales; see below). 