Severe underweight or significant overweight is associated with negative health consequences. In the United States, obesity is the primary weight issue affecting health and is associated with heart disease, diabetes, cancer and other life-threatening conditions. Insufficient body weight is associated with malnutrition in countries with political or ecological food shortages. Both underweight and overweight conditions correlate to increased mortality and shortened longevity. A healthy weight leads to longer life.
Underweight
In the United States, where a significant portion of the population is overweight or obese, studies of the correlation between low body weight and mortality are sparse. Underweight health conditions are more common in regions such as Rwanda, where the U.S. Agency for International Development reports that 23 percent of children are underweight, 4 percent severely so, due to political, economic and environmental factors which restrict access to adequate food. Underweight people are disproportionately likely to die of non-cancer and non-cardiovascular disease causes such as pneumonia, tuberculosis and asthma, according research published in 2007 by Katherine M. Flegal of the National Center for Health Statistics and colleagues. Lack of body mass may make it more difficult for underweight people to fight off certain illnesses, leading to higher mortality rates and reduced longevity.
Body Mass Index
Body fat levels, measured as body mass index, as well as daily exercise levels are important, independent measures of potential longevity, reports the Harvard School of Public Health. A high BMI is usually associated with excessive weight, and people with a lower BMI are those who tend to exercise more frequently. The Harvard School of Public Health determined that to maximize longevity, you should exercise daily and maintain a healthy, moderate BMI.
Caloric Intake
Daily caloric intake and body weight independently affect longevity, reports the University of Alabama Birmingham, which found in laboratory studies that obesity and excess daily caloric intake led to premature mortality in laboratory animals. The researchers were able to control their study in such a way as to determine that free access to unlimited calories and excess weight independently contributed to shortened lifespan in their animal subjects.
Overweight and Obesity
Obesity, defined as having a BMI of 30 and above, is associated with significantly increased mortality from causes such as diabetes, cardiovascular disease and cancer, Flegel concluded. Being of healthy weight or slightly overweight is associated with lower mortality rates from all causes.
References
- Harvard School of Public Health: Study Finds that Both Weight and Exercise are Key to Longevity
- USAID: Rwanda: Maternal and Child Health
- University of Alabama Birmingham: Caloric Intake, Body Weight Independently Affect Longevity
- Johns Hopkins Bloomberg School of Public Health: Cause-Specific Excess Deaths Associated with Underweight, Overweight and Obesity
