Effects of acute dietary restriction on gut motor, hormone and energy intake responses to duodenal fat in obese men

Each subject attended the laboratory on two occasions, once after an overnight fast (visit 1, day 1) and again following four days of a very low calorie diet (VLCD) (visit 2, day 6). On both visits, the effects of a 120-min intraduodenal infusion of a lipid emulsion (10% Intralipid), infused at a load of 2.86 kcal/min, on antropyloroduodenal (APD) motility, plasma cholecystokinin (CCK), peptide YY (PYY) and ghrelin concentrations, appetite, and energy intake were quantified. The four-day VLCD involved a 70% reduction of each individual’s energy intake, thus delivering 30% of their daily energy requirements. These were estimated using the Harris Benedict equation and a physical activity factor between 1.4-1.5 (indicative of light to moderate activity) based on an individual’s self-reported daily activity. To aid compliance with the VLCD, subjects were provided with a detailed individualised meal plan and the food items required for the diet period, including both liquid meal replacements (KicStart) and standard food items (sliced ham, wholemeal bread, salad items and pre-packaged frozen meals (Lean Cuisine beef lasagne/chicken stir-fry). The meal plan detailed the food items and their amount (g) to be consumed at each meal. In addition, subjects were permitted to consume an unlimited quantity of non-caloric beverages. To monitor compliance, subjects were required to document these (including brand names and quantities), as well as all the food consumed, throughout the 4-days, in a food diary. Subjects were also asked to maintain their normal physical activity over the course of the study and were contacted by phone during day 2 of the four-day diet to monitor their progress.