Life expectancy, mortality and longevity data related to height and body size for various US and world population samples are reviewed. Research on energy restriction, smaller body size and longevity is also examined. Information sources include various medical and scientific journals, books and personal communications with researchers. Additional information is presented based on research involving eight populations of the world noted for their health, vigor and longevity. This information includes the findings of one of the authors who led research teams to study these populations. While conflicting findings exist on the cardiovascular death rates for shorter people, many examples of short populations with very little heart disease are described. Most cancer studies indicate that shorter people have significantly lower mortality risk. Considerable data suggest that shorter people generally have greater longevity than taller people, and extensive animal research supports human longevity findings. Tall populations with low mortality rates are also described. Shorter stature and smaller body weight appear to promote better health and longevity in the absence of malnutrition and infectious diseases. Several theoretical reasons for this greater longevity potential are covered. Also discussed, is the role of socioeconomic status, diet, relative weight, environment and other factors in increasing or decreasing the longevity of individuals, regardless of their heights and weights.