“Glucose and fructose provide the same amount of energy, measured in calories. Glucose and fructose caused similar reductions in food consumption, but they affected food preferences differently. Studies have shown that when brain cells called agouti-related protein (AgRP) neurons are more active…{and} the theory {states} that nutrients like glucose and fructose reduce AgRP neuronal activity–and by extension hunger and appetite–equally.
A team of NIH-funded researchers, led by Dr. Amber Alhadeff of the Monell Chemical Senses Center and the University of Pennsylvania, recently tested that theory. They did so by comparing how AgRP neurons in mice respond to fructose versus glucose. This revealed that fructose is sensed by a distinct gut-brain pathway. They also suggest that fructose-related signals travel to AgRP neurons through the vagus nerve instead of the spinal cord. Their findings were published on June 10, 2026, in Neuron.
The scientists found that AgRP neurons were less active when mice consumed calories from glucose rather than fructose. High-fructose corn syrup, a mixture of fructose and glucose, suppressed AgRP neuron activity more than fructose alone. Glucose and fructose caused similar reductions in food consumption, but they affected food preferences differently. The results show that glucose has a larger effect than fructose on brain cells that influence eating behavior. This suggests that glucose’s larger effects on AgRP neurons might lead to a preference for foods sweetened with glucose over those containing fructose.”