“WHY FAST: Brain function. A neuroscientist Mark Mattson found that intermittent fasting increases levels of a protein called brain-derived neurotrophic factor, or BDNF. This, in turn, stimulates new brain cells in the hippocampus, the region of the brain that is responsible for memory. (Shrinking of the hippocampus has been linked to dementia and Alzheimer’s disease.) Increases mood. The protein called BDNF that helps improve memory also suppresses anxiety and elevates mood. Mattson showed this to be true in a study of rats. He injected BDNF into their brains, and it had the same effect as a regular antidepressant. Increases the effectiveness of insulin, the hormone that affects our ability to process sugar and break down fat. Reduces blood pressure. As your insulin level increases, so does your blood pressure. Insulin stores magnesium, but if your insulin receptors are blunted and your cells grow resistant to insulin, you can’t store magnesium; it ends up passing out of your body through urination. Magnesium in your cells relaxes muscles. If your magnesium level is too low, your blood vessels will constrict rather than relax, which will raise your blood pressure and decrease your energy level. Reduces triglycerides. Insulin upregulates LPL on fat tissue and inhibits activation on muscle cells. On the other hand, glucagon upregulates LPL on muscle and cardiac tissue, while inhibiting the activation of fat. Weight loss. You burn fat, rather than sugar, in a fasted state.”