The researchers reviewed evidence on widely used sweeteners such as table sugar (sucrose) and high-fructose corn syrup. Although both contain glucose and fructose, the scientists say fructose behaves differently inside the body and may play a more direct role in obesity and related health problems.

“Fructose is not just another calorie,” said Richard Johnson, MD, professor at the University of Colorado Anschutz and study lead author. “It acts as a metabolic signal that promotes fat production and storage in ways that differ fundamentally from glucose.”

How Fructose Affects Metabolism

According to the report, fructose is processed through metabolic pathways that bypass some of the body’s normal regulatory controls. This process can increase fat production, reduce cellular energy levels (ATP) and generate compounds associated with metabolic dysfunction.

Over time, these biological changes may raise the risk of metabolic syndrome, a group of conditions linked to obesity, insulin resistance and cardiovascular disease.

The researchers also note that fructose exposure is not limited to food and beverages alone. The body is capable of producing fructose internally from glucose, which suggests its contribution to disease could be broader and more complex than scientists once believed.

Concerns About Rising Sugar Consumption

The findings arrive as obesity and diabetes rates continue to climb around the world. While sugary drink consumption has declined in some countries, intake of “free sugars” remains higher than recommended in many parts of the world and is still increasing in others.

The researchers suggest fructose may once have provided an evolutionary advantage. By helping the body store energy efficiently, it could have supported survival during periods of famine or food shortages. However, in modern environments where calorie-rich foods are constantly available, the same biological mechanisms may now be contributing to chronic disease.

“This review highlights fructose as a central player in metabolic health,” said Johnson. “Understanding its unique biological effects is critical for developing more effective strategies to prevent and treat metabolic disease.”