Prevalence of excess weight has increased by more than two-fold over the past 30 years. Two third of US adults are currently overweight, and one third suffer from obesity. This has resulted in a public health epidemic with significant human and economic impact. If the current trend continues, it is estimated that by 2030 one half of US adult population will suffer from obesity.
Excess weight has a detrimental impact on quality of life. Individuals suffering from excess weight report decreased tolerance of physical activities and increased fatigue. They find their excess weight an impediment to performance of day-to-day activities and work-related functions. They may experience anxiety, depression, and decreased self-esteem.
Excess weight can also have a detrimental impact on health. Metabolic syndrome, resulting from excessive accumulation of adipose tissue, affects many organ systems and directly impacts health through disorders like diabetes, high blood pressure, coronary artery disease, obstructive sleep apnea, and degenerative joint disease. Each of these conditions can in turn result in secondary disorders. Diabetes, a leading public health challenge, can result in deterioration of kidney function and eyesight, and decreased ability to fight infection through its negative impact on immune system.
High blood pressure is a major source of cardiovascular morbidity, negatively impacting the heart and blood vessels, resulting in increased risk of heart attack and stroke.
Musculoskeletal disorders such as osteoarthritis can destroy articular cartilages within weight-bearing joints, resulting in chronic pain and disability, and requiring major surgical corrective procedures such as knee and hip replacement. Excess weight is also associated with increased incidence of many cancers.
Considering the burden of morbidities associated with excess weight, it is not surprising to find that excess weight is associated with increased risk of premature death and decreased longevity. The good news, however, is that excess weight is a preventable cause of death, much like smoking. When individuals lose their excess weight, majority of their obesity-related co-morbidities resolve completely or improve significantly. With that, they can expect increase in quality of life, functional ability, satisfaction with social interactions, and emotional well-being.
For individuals with severe excess weight, losing weight with diet and exercise has been is associated with over 90% failure rate. Although many are able to lose weight, they find it difficult to maintain a lower weight. Until recently, this was attributed to lack of will power. However, research has shown that during an intentional period of caloric restriction, our body exhibits a complex metabolic response resulting in significant decrease in metabolic rate and increase in hunger. Together, these changes counter the efforts of weight loss and contribute to weight regain.