Year: 2007
Type: dissertation
Abstract: This research examined the hypothesis that biomarkers of food intake regulation in men are affected by hyperinsulinemia and insoluble fiber. The primary objectives were to determine (1) the effect of hyperinsulinemia on food intake and plasma concentrations of glucose and appetite regulatory hormones in men after a glucose drink, (2) the effect of insoluble fiber intake on appetite, short-term food intake and postprandial blood glucose before and in response to a meal 1 hr later in healthy men, and (3) the effect of one month intake of a high insoluble fiber cereal on appetite, food intake and postprandial response of glucose, insulin, Cholecystokinin (CCK), leptin and adiponectin to a glucose load, and to measure the effect of a single serving of the high insoluble fiber cereal on satiety response to a glucose load in hyperinsulinemic non-diabetic men. Three studies were conducted. Subjective appetite was measured and blood samples were collected for analysis of plasma lipids, glucose, insulin, CCK, leptin and adiponectin. Food intake from a pizza meal was measured lhr after a glucose load (75g) (Study 1) or low and high insoluble fiber cereal treatments (Study 2), and 3 hrs after a low and high fiber ready-to-eat cereal followed by a glucose load (Study 3). Hyperinsulinemia was found to improve food intake compensation in association with elevated fasting concentrations of insulin and leptin, and higher postprandial insulin, glucose, CCK, leptin, and lower ghrelin concentrations. Insoluble fiber increased satiety, lowered food intake at the next meal and reduced glycemic response after the next meal in healthy men. One month of consumption of high insoluble fiber cereal did not alter food intake response to a glucose load, however, an increase in several regulatory hormones approached statistical significance and a serving of high fiber cereal increased subjective satiety compared with low fiber cereal. Taken together, these results provide support that both hyperinsulinemia and insoluble fiber contribute to improved food intake regulation. Hyperinsulinemia enhanced biomarkers of satiety and may be a component of the mechanism explaining its effect. However, mechanisms explaining the effect of insoluble fiber on food intake control, while undefined, merit exploration.
Source: TSpace (University of Toronto)
Author: Samra, Rania Abou
Institution: University of Toronto
Language: English
Subfield: Endocrine and Autonomic Systems
Field: Neuroscience
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7132905200