Obesity is a worldwide epidemic. Nearly 60% of Americans are overweight and 30% are obese (body mass index [BMI] >30 kg/m2).26,55 Even more alarming, the incidence of obesity in children between the ages of 6 and 19 years has tripled in the past 30 years.9 Nearly 9 million children and adolescents are now considered overweight.9 Obesity contributes to 325,000 deaths annually in the United States.5 Obesity is linked to numerous health risks, including type II diabetes, hypertension, coronary heart disease,9,19 metabolic syndrome138 and even low back pain.119 Because of this, it can be considered a leading preventable health risk, second only to cigarette smoking. In the past several decades, research has been dedicated to the pathophysiology of obesity and to novel therapeutic approaches. Genetic links, including particular genepolymorphisms, have been identified and are being pursued.3,23,73
Americans spend $33 billion per year on weight loss therapies and modalities. Dieting and weight loss are attempted by many more people than just those who are overweight and obese by medically defined criteria. Weight loss management is difficult and frequently even the best lifestyle modifications only result in a modest weight loss in a majority of people. Pharmacologic interventions may result in a 5% to 10% weight loss, although a return to baseline upon drug cessation is common.40 Surgical interventions consistently achieve substantial weight loss, causing up to a 30% reduction in weight, but are not free from complications.2,16
Obesity and attempts at weight loss have probably existed since antiquity. One of the earliest accounts of weight loss therapy dates back to 10th-century Spain. King Sancho I, who was obese, underwent successful treatment with a "theriaca," thought to contain plants and possibly opioids, administered with wine and oil. In addition, he was closely supervised and treated by a physician.60
Currently, medicinal weight loss therapies (Table 39–1) are available as prescription medications (sibutramine, phentermine); nonprescription dietary supplements (Citrus aurantium, chitosan, Garcinia cambogia, caffeine); and in late 2007, orlistat, a fat blocker, was approved as a nonprescription diet aid. Acquisition and utilization of natural weight loss remedies have undergone a resurgence since passage of the Dietary Supplement Health and Education Act (DSHEA) of 1994, which created a new category separate from food and drugs. As a result of the DSHEA, numerous botanicals and other substances are offered to consumers as weight loss aids, some with no proven efficacy and some with potentially serious toxicity.
Table 39–1. Available Weight Loss Drugs and Dietary Supplements |Favorite Table|Download (.pdf)
Table 39–1. Available Weight Loss Drugs and Dietary Supplements
|Drug or Supplementa||Mechanism of Action||Regulatory Status||Adverse Effects/Contraindicationsb|
|Diethylpropion (Tenuate)||Increased release of norepinephrine and dopamine||Schedule IV prescription drug||Dry mouth, ...|