The Journal of the American Medical Association (JAMA) just published a study which compared the effects of fructose vs glucose on the brain in order to determine if there was an association between fructose consumption and weight gain.
Fructose is found in fruit and it is also found in some processed foods, especially as high fructose corn syrup. Fructose is used as a sweetener and also as a stabilizer in processed foods.
The results of the study showed that glucose ingestion, but not fructose ingestion, reduced activation to the areas of the brain that regulate appetite and reward and it also increased brain to brain connections that were responsible for feelings of satiety. Fructose does not appear to affect the brain the same way as glucose; it does not appear to turn of the areas of the brain responsible for appetite. The authors note that this is probably because after fructose ingestions there is a of the reduced levels of insulin, the hormone responsible for satiety signaling.