THE DISRUPTED BODY CLOCK

These chapters look at how our digital lives affect the systems in our body that control sleep, vision, posture, heart health, metabolism and how our gut and brain talk to each other. Using screens in the evening messes with our body's rhythm by reducing the hormone that makes us sleepy changing the part of the brain that controls our sleep and triggering stress responses that make us stay awake and disrupt our rest. Not getting sleep leads to big hormonal changes that affect how we regulate our appetite, process sugar respond to illness and the signals that control growth and reproduction. Spending much time on screens also causes eye strain and muscle stress because we focus on things that are close to us blink less sit in bad positions and change how our neck and eyes work together making us feel uncomfortable, tired and mentally strained. At the level of our heart and metabolism ongoing digital stress triggers pathways in our body that lower our heart rate variability raise our blood pressure cause inflammation in our blood vessels make our body resistant to insulin and increase our risk of heart and metabolic problems in the long run.