Gastric and Intestinal Satiation in Obese and Normal Weight Healthy People

The purpose of this study is to determine the reciprocal control between gastric functions and intestinal parameters in the development of satiation in obese people.

Obesity has reached pandemic proportions, obesity-associated complications are extensive and the current treatment options are limited. These facts demonstrate the need for an improved understanding of the pathogenesis of obesity. The gastrointestinal tract plays a key element in the control of satiation; discrepancies exist, however, for the role of gastric and intestinal parameters in the control of satiation in relation to body mass. To achieve a comprehensive understanding for the reciprocal control between gastric functions and intestinal parameters in the development of satiation in obese people the investigators will compare satiation parameters, gastric emptying and plasma glucagon-like peptide-1 (GLP-1), peptide tyrosine tyrosine (PYY) and ghrelin levels between normal and obese healthy volunteers. Time needed to reach the level of satiation and total calorie intake will be measured by a standardized nutrient drink test; gastric emptying of solids by a 13C-octanoic acid breath test; and plasma GLP-1, PYY and ghrelin levels will be measured after a standardized nutrient drink.

glucagon-like peptide-1, peptide tyrosine tyrosine, ghrelin, stomach, small intestine, gastric emptying

Obese subjects will receive a complex nutrient drink (Ensure Plus; 17 % protein, 30 % fat and 53 % carbohydrate, 1 kcal/mL). Nutrient intake will be stopped when subjects had reached maximal or unbearable satiation; the time needed to reach the maximal level of satiation (tmax) and the quantity of volume drunk will be recorded and calorie intake calculated.

Obese subjects will receive a standardized meal, consisting of two scrambled eggs (cooked with 10 g butter), placed on two slices of whole wheat bread and 200 mL of milk (in total: 468 kcal). The test meal will be labeled with 100 mg of 13C-octanoic acid for determination of gastric emptying.

Normal weight subjects will receive a standardized meal, consisting of two scrambled eggs (cooked with 10 g butter), placed on two slices of whole wheat bread and 200 mL of milk (in total: 468 kcal). The test meal will be labeled with 100 mg of 13C-octanoic acid for determination of gastric emptying.

Normal weight subjects will receive a complex nutrient drink (Ensure Plus; 17 % protein, 30 % fat and 53 % carbohydrate, 1 kcal/mL). Nutrient intake will be stopped when subjects had reached maximal or unbearable satiation; the time needed to reach the maximal level of satiation (tmax) and the quantity of volume drunk will be recorded and calorie intake calculated.

Obese subjects will receive 500 mL of a complex nutrient drink (Ensure Plus; 17 % protein, 30 % fat and 53 % carbohydrate). At regular time intervals fasting and post-prandial blood samples will be collected.

Normal weight subjects will receive 500 mL of a complex nutrient drink (Ensure Plus; 17 % protein, 30 % fat and 53 % carbohydrate). At regular time intervals fasting and post-prandial blood samples will be collected.

Inclusion Criteria: healthy subjects age 18-45 Exclusion Criteria: smoking substance abuse regular intake of medication medical or psychiatric illness gastrointestinal disorders or food allergies

Meyer-Gerspach AC, Wolnerhanssen B, Beglinger B, Nessenius F, Napitupulu M, Schulte FH, Steinert RE, Beglinger C. Gastric and intestinal satiation in obese and normal weight healthy people. Physiol Behav. 2014 Apr 22;129:265-71. doi: 10.1016/j.physbeh.2014.02.043. Epub 2014 Feb 28.