Obesity is a modern-day epidemic. In the United States in 2018, approximately 42.4% of adults were obese (a body mass index – BMI – over 30), according to the CDC National Center for Health Statistics. Even more alarming is the increasing prevalence in youth — 19.3% of 2- to 19-year-old youths were obese in 2018. Related to obesity is the metabolic syndrome: a cluster of metabolic dysfunctions, which include obesity, as well as hypertension and increased fat levels in the blood.
- Obesity raises the risk of developing co-existing conditions, including type 2 diabetes, arthritis, and asthma, and is the leading risk factor for heart disease and certain types of cancer.
- Obesity negatively impacts the peripheral nervous system, and can result in nerve damage in the legs and arms, known as peripheral neuropathy. It can also injure the network of nerves that regulate heart function.
- Obesity damages both brain structure and function, promoting problems with cognition and thinking.
- General obesity is frequently measured by BMI, but can also be measured by comparing proportions of the body. Central obesity, for example, is defined by waist circumference. Other obesity measurements include hip, upper and lower arm, and thigh circumferences, in addition to waist-to-hip ratio.