Prevalence of excess weight has increased by more than two fold over the past 30 years. Two third of the 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 the 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, to name a few. Each of these conditions can in turn result in secondary disorders. Diabetes, a leading public health challenge, can result in deterioration of kidney function, nerve function, and eyesight, and decreased ability to fight infection through its negative impact on the immune system.

High blood pressure is a major source of cardiovascular morbidity, negatively impacting the heart and blood vessels, and 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 disease associated with excess weight, it is not surprising 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 and maintain a near normal weight, majority of their obesity-related co-morbidities resolve completely or improve significantly, and they can regain longevity. And because weight loss brings about significant improvement in quality of life and psychological well-being, the added years are qualitatively superior.

Unfortunately, for individuals with severe excess weight (30-40 lbs. or more), losing weight with diet and exercise has been associated with high 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 own body exhibits a complex metabolic response resulting in significant decrease in metabolic rate and increase in hunger. Together, these changes counter our efforts of weight loss and contribute to weight regain. The good news is that bariatric metabolic surgery can put a stop to that detrimental metabolic response via alteration of gastrointestinal hormones such as Ghrelin (hunger hormone) and Peptide YY (a satiety hormone). Following bariatric surgery, contrary to what is seen with dieting, patients experience decreased hunger and increased metabolic rate in spite of reduced calorie intake. This complimentary metabolic response with bariatric surgery helps greatly in long-term maintenance of weight.

Watch Dr. Zaré's 2015 lecture at Good Samaritan Hospital, San Jose, on how bariatric surgery can improve metabolism.