Studies have found that glucose level plays a significant role in decision-making and self-control, as it affects energy available to the entire system. Researchers such as Roy Baumeister have found that people who have not eaten recently have poorer performance on decision-making tasks that test self-control than those who ingested calories. Specifically he notes that “glucose is the chemical in the bloodstream that carries energy to the brain, muscles and other organs and systems. In simple terms, glucose is fuel for the brain. Acts of self-control reduce blood glucose levels. Low levels of glucose predict poor performance on self-control tasks and tests. Replenishing glucose, even just with a glass of lemonade, improves self-control performance.”
Glucose is brain fuel and we need it to make well thought out decisions. If you are someone struggling with craving states, and you haven’t eaten in the last 3 hour window, try a little snack before you decide to ‘temporarily suspend” your substance goals (“I’ll just have a couple quick drinks with the guys this one time”). A little brain fuel might help you stick with your original plan.