The type of sugar in your beverage could affect whether or not you feel hungry after drinking it. In a study published in the Journal of the American Medical Association, researchers determined that fructose and glucose are processed differently in the brain. Both are simple sugars, yet fructose did not cause participants to feel full, whereas glucose did.
Using magnetic resonance imaging to map the brains of 20 test subjects, the study authors discovered that the glucose drink suppressed activity in the hypothalamus and other brain regions that regulate appetite, motivation and reward processing, while the fructose drink did not. The responses to the fructose-based drinks were associated with reduced levels of insulin, a hormone responsible for sending satiety messages to the brain.