Chemistry and Health: Fooled by Molecular Shape

• Artificial sweeteners, such as aspartame, taste sweet but have few or no calories. Taste and caloric value are entirely separate properties of foods.
• The caloric value of a food depends on the amount of energy released when the food is metabolized.
• Sucrose (table sugar) is metabolized by oxidation to carbon dioxide and water:

C12H22O11 + 6 O2  12 CO2 + 11 H2O

ΔH = −5644 kJ

• Some artificial sweeteners, such as saccharin, are not metabolized at all—they pass through the body unchanged—and therefore have no caloric value.
• Other artificial sweeteners, such as aspartame, are metabolized but have a much lower caloric content (for a given amount of sweetness) than sucrose.