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Physiological mechanisms mediating aspartame-induced satiety
W L Hall1, D J Millward, P J Rogers
1Centre for Nutrition and Food Safety, School of Biomedical and Life Sciences, University of Surrey, Guildford, Surrey GU2 7XH, UK. w.l.hall@reading.ac.uk
Physiology & Behavior
|June 5, 2003
Summary
Aspartame and its components, phenylalanine and aspartic acid, did not affect satiety hormones cholecystokinin (CCK) or glucagon-like peptide-1 (GLP-1). However, amino acids reduced appetite, potentially linked to phenylalanine levels.
Area of Science:
- Endocrinology
- Gastroenterology
- Nutritional Science
Background:
- Aspartame is known to increase satiety.
- The underlying mechanisms, particularly involving satiety hormones, are not fully understood.
- This study investigates the role of cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1) in aspartame's satiety effects.
Purpose of the Study:
- To determine if aspartame or its constituents (phenylalanine and aspartic acid) influence CCK and GLP-1 secretion.
- To examine the impact of aspartame and its constituents on gastric emptying and appetite regulation.
- To explore the relationship between circulating amino acid levels and appetite.
Main Methods:
- Six subjects consumed preloads of aspartame, aspartic acid + phenylalanine, or a control (corn flour).
- Gastric emptying was measured using paracetamol absorption.
- Plasma levels of CCK, GLP-1, GIP, glucose, and insulin were measured after a liquid meal.
Main Results:
- Aspartame and amino acid preloads did not alter plasma CCK, GIP, glucose, or insulin levels.
- Plasma GLP-1 concentrations decreased after the liquid meal in both aspartame and amino acid groups compared to control.
- Amino acid preloads significantly reduced the desire to eat, correlating with increased plasma phenylalanine.
Conclusions:
- Aspartame's satiety effect is unlikely mediated by CCK or GLP-1.
- Changes in circulating phenylalanine may play a role in appetite regulation.
- Gastric emptying and other measured hormonal responses were not significantly affected by aspartame or its constituents.
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