I have studied longevity and height for about 40 years and I have published in about 40 medical, nutritional, and scientific journals and books. My work has found a longevity advantage for shorter people. A number of biological mechanisms are at work to promote longevity for smaller people. These include: 1. Fewer cell replications allow a reserve of cells for use during old age. 2. Insulin and other growth factors are lower and low levels are related to greater longevity. 3. Smaller left ventricular mass of the heart is related to reduced heart failure and all-cause mortality. 4. Lower levels of C-reactive protein, homocysteine, and glucose reduce mortality. 5. Lower blood pressure. 6. Lower damage to DNA. 7. Lower free radical generation with reduced cell damage. 8. Higher sex hormone binding globulin [low levels have a variety of harmful effects.] The above assumes similar economic status, lifestyle, and body proportions. Height is about 10% of the longevity picture. Therefore, tall people can offset their tall height by improved nutrition, lower weight and lifestyle habits. However, I found that we lose about 1.3 years per inch of increased height. For more information on how our physiology, performance and impact on resources and the environment change with increasing body size, see www.humanbodysize. The book, The Truth About Your Height, provides information on height as well.