What Is the Difference Between Glucose & Fructose?

Glucose and fructose are types of carbohydrates. Carbohydrates are compounds produced by the photosynthesis of plants. They're made up of carbon, hydrogen and oxygen atoms, and their main function is to supply energy to living cells.

Classification

The carbohydrates we eat come in three forms--sugars, starches and cellulose. Both glucose and fructose are classified as simple sugar carbohydrates, or monosaccharides.

Source

All carbohydrates originate from plants. But fructose is specifically found in fruits and honey, and glucose is specifically found in plant sap.

Distinctions

Fructose is the sweetest of all sugars, including glucose. And while glucose and fructose share the molecular formula C6H12O6, the structure of the six carbon, 12 hydrogen, and six oxygen atoms of each molecule is different.

Molecular Structure

Oxygen atoms in these two sugars form bonds differently. Glucose forms an aldehyde compound sugar, while fructose forms a ketone sugar.

Function

Your body is able to convert glucose into energy with greater efficiency than it can convert fructose. And unlike glucose, fructose does not trigger the release of insulin, nor does it increase leptin production. Insulin and leptin are homones that help regulate hunger and body weight.

Effects

Many scientists believe that high fructose diets can lead to calorie overconsumption and weight gain.

References

• Georgia State University HyperPhysics: Comparison of Glucose and Fructose
• UT Southwestern Medical Center: "Limiting fructose may boost weight loss"
• American Society for Clinical Nutrition, 2004: "Consumption of high-fructose corn syrup in beverages may play a role in the epidemic of obesity"