Lifespan or Maximum Lifespan is referred to as the greatest age reached by any member of a given population (or species). For humans, the lifespan is currently between 120 and 125. Life Expectancy is defined as the average number of years that members of a population (or species) live. According to the World Health Organization (WHO) (2016) global life expectancy at birth in 2015 was 71.4 years, with females reaching 73.8 years and males reaching 69.1 years. Women live longer than men around the world, and the gap between the sexes has remained the same since 1990. Overall life expectancy ranged from 60.0 years in the WHO African Region to 76.8 years in the WHO European Region. Global life expectancy increased by 5 years between 2000 and 2015, and the largest increase was in the WHO African Region where life expectancy increased by 9.4 years. This was due primarily to improvements in child survival and access to antiretroviral medication for the treatment of HIV. According to the Central Intelligence Agency (2016) the United States ranks 43rd in the world for life expectancy.

World Healthy Life Expectancy: A better way to appreciate the diversity of people in late adulthood is to go beyond chronological age and examine how well the person is aging. Many in late adulthood enjoy better health and social well-being than average and would be aging at an optimal level. In contrast, others experience poor health and dependence to a greater extent than would be considered normal. When looking at large populations, the WHO (2016) measures how many equivalent years of full health on average a newborn baby is expected to have. This age takes into account current age-specific mortality, morbidity, and disability risks and is referred to as The Healthy Life Expectancy. In 2015, the global Healthy Life Expectancy was 63.1 years up from 58.5 years in 2000. The WHO African Region had the lowest Healthy Life Expectancy at 52.3 years, while the WHO Western Pacific Region had the highest at 68.7 years.

Life Expectancy in America: In the United States the overall life expectancy is 79.7 years, however, life expectancies vary by sex, race, and ethnicity. Table 9.3 shows the life expectancy of three demographic groups for males and females for a child born in 2012 (Ortman et al., 2014). As can be seen, females enjoy a longer life expectancy, and overall Hispanics have the highest life expectancy.

Table 9.3 2012 U. S. Life Expectancy by Sex, Race, and Ethnic Origin in Years

American Healthy Life Expectancy: To determine the current United States Healthy Life Expectancy (HLE), factors were evaluated in 2007-2009 to determine how long an individual currently at age 65 will continue to experience good health (CDC, 2013). The highest Healthy Life Expectancy (HLE) was observed in Hawaii with 16.2 years of additional good health, and the lowest was in Mississippi with only 10.8 years of additional good health. Overall, the lowest HLE was among southern states. Females had a greater HLE than males at age 65 years in every state and DC. HLE was greater for whites than for blacks in DC and all states from which data were available, except in Nevada and New Mexico.

Although improvements have occurred in overall life expectancy, children born in the United States today may be the first generation to have a shorter life span than their parents. Much of this decline has been attributed to the increase in sedentary lifestyle and obesity. According to the American Heart Association (2014), currently one in three American children is overweight or obese. The rate of childhood obesity tripled from 1971 to 2011, and obesity in children is associated with a range of health problems, including high blood pressure, type 2 diabetes, elevated blood cholesterol levels, and psychological concerns including low self-esteem, negative body image and depression. Excess weight is associated with an earlier risk of obesity-related diseases and death. In 2007 former Surgeon General Richard Carmona stated, “Because of the increasing rates of obesity, unhealthy eating habits and physical inactivity, we may see the first generation that will be less healthy and have a shorter life expectancy than their parents” (p. 1).