Obesity is a condition whereby excessive fat tissue accumulates and is usually diagnosed by using weight and height to calculate body mass index, or BMI. A person can have a low, normal, overweight, or obese BMI. A BMI greater than 40 is considered morbidly obese. About 3.5 percent of Americans are morbidly obese, which does not sound like a high number until you realize that it translates to about 12.5 million people. It’s as if every person who lives in New York City, Boston, and Philadelphia is morbidly obese.

According to the World Health Organization (WHO), 39 percent of adults globally are overweight and 13 percent are obese. In the United States, the rates of obesity are known to exceed those in the rest of the world, with 69 percent of Americans overweight and 35 percent obese. A lot of this is due to the proliferation of internet use (due to drops in leased line costs) and the fact that most young children prefer indoors to the outdoors.

Obesity is also a significant risk factor for a host of medical problems, including diabetes, cancer, heart disease and stroke, high blood pressure, osteoarthritis, respiratory problems, and mood disorders. All this extra weight is a leading reason why people live with persistent pain.

Central obesity is characterized as excessive abdominal fat around the stomach, abdomen, and back. Fat accumulation in this part of the body has a negative impact on health. Obesity remains a critical population health concern because of its effects on pain, disease, disability, and health-care costs.

There is a definitive link between excess weight and painful conditions, such as osteoarthritis, spinal and joint pain, autoimmune disease, diabetes, and metabolic syndrome. It is now clear that mechanical (the body’s physical makeup), metabolic (the internal chemical reactions), and psychosocial factors (behavior, environment, and lifestyle) all have significant contributing and lasting effects on this chronic health problem. The lifestyle you lead directly impacts your ability to live healthy or live in pain. According to the Arthritis Foundation, losing 15 pounds may decrease knee pain by 50 percent. Just as weight gain causes more pain, weight loss reduces pain. You have the power to increase or decrease your pain—and it’s tied directly to your weight.

There is no doubt that as we have gained weight, so, too, have we carried more pain. Studies from the early 1990s point to one in seven people struggling with persistent pain, whereas more recent studies now support a much higher percentage: Almost 25 percent of us live with persistent pain. As our obesity epidemic has risen, so, too, have the levels of pain we carry.