Being overweight and obesity are major, global health care problems, causing a myriad of physical health and psychological/social problems.

There are numerous health risks associated with obesity and being overweight, including:

• Heart disease and stroke
• High blood pressureHeart disease and stroke
• Diabetes
• Cancer
• Gallbladder disease and gallstones
• Osteoarthritis
• Gout
• Breathing problems, such as sleep apnea and asthma
• Kidney diseases

Obesity is arguably the single biggest healthcare crisis in the world today. From 1960 to 1980, the obesity rate in the United States remained fairly constant. Since 1980, the number of obese people in the United States has tripled. This staggering increase has been fueled by growing rates of obesity across all ages, ethnic groups and socioeconomic classes. And while the United States has one of the highest rates of obesity in the world, most developed countries have seen similar growth in obesity rates.

Most people eat until they feel full. Fullness is determined less by the calories consumed and more by the volume of food consumed. The past few decades have seen energy-dense processed food become a larger and larger share of diets around the world leading people to consume more calories before they feel full. This diet, together with increasingly sedentary lifestyles, is driving the epidemic growth in the number of obese people.

The World Health Organization (WHO) uses Body Mass Index (BMI) to classify people based on height and weight. BMI is a measure of weight relative to height.

In 2005 WHO estimated that approximately 1.6 billion adults were overweight and at least 400 million were obese. By 2015, WHO estimates that 2.3 billion people will be overweight and 700 million will be obese. And the fastest growing segment is the morbidly obese.