This document discusses quantified self and self-tracking in health. It provides examples of individuals who track various health metrics like blood glucose, exercise, diet, biomarkers and have found benefits like reduced insulin needs, weight loss, and cured illnesses. Common metrics tracked include blood glucose, heart rate, inflammation, microbiome, and DNA. The quantified self movement values first-person observations and experimentation to gain insights into one's own health and ways to improve it through lifestyle tracking and changes. There is a goal to aggregate user data to gain broader health insights through projects like the 100k Wellness Project.