It was long thought that the brain was an insulin independent. However, this was quickly recanted after the identification of insulin receptors in the brain. Insulin action influences brain function in various outcomes, thus affecting memory, eating habits, etc. PD Dr. Kullmann focused in her presentation on the aspects of insulin and its effect on eating behaviors as well as the brain activity.
For men, the central insulin diminishes the feeling of hunger and food craving. For women, this effect is only seen in the postprandial state. Modulated by wanting, the prefrontal cortex activity in men decreases under insulin. However, the opposite pattern is seen in women. This allows for the conclusion that women demonstrate a higher central insulin-induced prefrontal cortex activity by appetizing food cues.
Furthermore, Kullmann looked at the factors that may correlate with this difference and found that the cognitive restraint score correlates with food-cue activity in the prefrontal cortex. Women who show a higher central insulin-induced prefrontal cortex activity also had a higher cognitive restraint.
Insulin plays an important role in reward and decision making in regards to nutrition as well as there are sex-specific differences. These different reactions in women and men need to be further examined to be able to further identify what mechanisms determine this.