Kelly Higgins is a nutrition and food scientist with ten years of experience evaluating relationships between diet, ingestive behavior, and health. Dr. Higgins received her food science doctoral degree and Master of Public Health from Purdue University and her dual bachelor’s degrees in nutritional sciences and biochemistry from the University of Missouri. She has designed and conducted three long-term clinical trials investigating the effect of low calorie sweetener exposure on outcomes of body weight, taste perception, preference, appetite, and glycemia. Dr. Higgins is currently a Managing Scientist at Exponent Inc., a scientific consulting company, where she leads assessments of the health benefits and risks of dietary exposures and estimates usual food and nutrient intake and nutrient adequacies using data collected as part of the National Health and Nutrition Examination Survey (NHANES). Prior to Exponent, Dr. Higgins was a Nutrition Scientist at the U.S. Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Center, Food Components and Health Laboratory (FCHL). In this role, Dr. Higgins’ conducted research investigating the effect of sensory properties and palatability of the diet on body composition and ingestive behavior. She developed the FCHL five-year plan to study food processing and food characteristics that affect ingestive behavior and diet-related chronic disease risk. Dr. Higgins also led an initiative to design and initiate a 7-month controlled feeding randomized controlled trial of over 90 participants to investigate diet-induced modification of sweet taste perception and preference.
Low calorie sweeteners (LCS) comprise a group of chemical compounds that provide sweetness with little or no metabolizable energy. Once believed to be inert beyond the oral cavity, evidence suggest that specific LCS may bind to the T1R2/T1R3 taste receptor located in tissues throughout the body and influence biological processes post-ingestion. There is ongoing debate among researchers regarding whether the consumption of sweetness without accompanying energy might have unintended effects on the sensory, pre-ingestive, post-ingestive, and cognitive processes that regulate energy intake and glycemia. Numerous mechanisms have been put forth to elucidate the potential positive or negative impacts of LCS consumption on body weight and glycemia. Sweetness exposure without energy has been posited as a mechanism LCS could result in either negative or positive energy balance. LCS intake might decrease energy consumption by diluting the energy content of the diet when substituted for energetic sweeteners. Conversely, the incorporation of LCS into the diet could heighten the palatability of the diet and consequently increase energy intake. Some scientists hypothesize that the delivery of sweetness without energy disrupts or "decouples" the conditioned association between sweetness and the post-ingestive consequences of carbohydrate consumption, leading to energy and glycemic dysregulation. The objective of this session is to outline the suggested mechanisms LCS consumption might influence energy and glycemic regulation, and to present the existing evidence from both animal and clinical studies that support or refute each of these mechanisms. Differences between LCS in these mechanisms will be highlighted when applicable. Key Points: • Recent dietary guidance suggests that dietary sweetness regardless of the source should be avoided for body weight management despite the limited availability of published evidence supporting this relationship. • Evidence from animal studies investigating the associative learning of chemosensory stimuli and predictive energy is often not translatable to humans due to differences in dietary exposures, sensory perception, preferences, and carbohydrate metabolism between humans and other species. • Low calorie sweeteners are distinct compounds with varying chemical structures, taste profiles, receptor affinities, digestive, and metabolic fates; each of these factors could influence the mechanisms that each specific low calorie sweetener may affect.