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G. H. ANDERSON, R. Abou Samra, and T. Akhavan. Dept. of Nutritional Sciences, Univ. of Toronto, 150 College St., 322 FitzGerald Bldg., Toronto, ON M5S 3E2, Canada This presentation will address the following 4 controversies surrounding the consumption, metabolism, and effects on satiety of sugars. Sugars are either mono- or disaccharides and include sucrose, lactose, maltose, glucose and fructose. First, it has been suggested that consumption has increased from sugars and high glycemic index carbohydrates and that they are the cause of obesity through bypassing regulatory systems and exacerbating hunger. However, the availability of added sugars has not increased disproportionately to the total energy in the food supply and experimental studies show remarkably precise compensation in subsequent meals for the energy contained in sugars. Second, the glycemic indices of glucose, fructose, sucrose, maltose, and lactose expressed relative to 100 for white bread, are 143, 27, 97, 150 and 66, respectively. Contrary to the belief that sugars produce high blood glucose concentrations, fructose and sucrose have lower GI values by up to 50% compared to many common carbohydrate foods. Third, although experimental evidence shows that a high glycemic response associates with lower short-term food intake, higher glycemic index carbohydrates, and sugars, have been hypothesized to increase food intake by stimulating an excess insulin response that results in glucose concentration falling below baseline, thus increasing hunger and. When tested this hypothesis has not been supported. Fourth, the replacement of sucrose with corn sweeteners has been hypothesized to contribute to obesity and associated diseases, based on the assumption of increased consumption of fructose and its rapid conversion to fatty acids by the liver. However the ratio of fructose to glucose in the food supply has changed little over time. Furthermore, experimental studies showing an increase in blood lipids after fructose consumption were based on diets containing two to three time the approximately 8% of energy derived from fructose in the average diet.
Session 14, The complexity of carbohydrates!
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |