In another study, four days of continuous fasting increased BMR by 12 percent. Levels of the neurotransmitter norepinephrine (also known as noradrenaline), which prepares the body for action, increased by 117 percent, keeping energy levels high. Fatty acids in the bloodstream increased over 370 percent as the body switched over from burning food to burning stored fats. Figure 3.1. During fasting, basal metabolism and exercise capacity are
