Epidemiologic and Etiologic Considerations of Obesity

Excerpt

For much of the twentieth century, cigarette smoking was the most common preventable cause of morbidity and mortality. However, there has been a paradoxical decrease in tobacco use and a subsequent increase in obesity. In simple terms, obesity occurs when caloric intake exceeds energy expenditure. This chronic and often progressive condition is debilitating and has far-reaching implications extending far beyond the afflicted and into society. The causes of obesity involve genetics, socioeconomic, diet, physical activity, medications, medical conditions, and culture.

Genome-wide databases have identified more than 500 specific gene loci related to the development of obesity. Those genes can have profound lifelong implications (e.g., Prader-Willi syndrome, Bardet-Biedl syndrome). Researchers have discovered racial disparities in the development of obesity. Various prenatal/childhood factors and normal aging has an association with the development of adult obesity. In addition, those with sedentary lifestyles tend to make poor choices in food selection and adopt a daily caloric intake that does not match their energy expenditure. As a result, this caloric excess is the primary driver in the development of obesity.

Health professionals should be aware of various medications known to cause obesity. In addition, various medical conditions affecting the hypothalamic-pituitary axis (HPA) can contribute to obesity onset. Recently, investigators have become interested in the role of the gut microbiome in the development of obesity, particularly in the proportion of two-bacterial strains (Bacteriodes and Firmicutes) in the gut microbiome and the role of endocrine-disrupting chemicals.

Finally, the development of chronic obesity produces a cascade of downstream molecular targets leading to the development of dyslipidemia, hypertension, and diabetes. This unique cluster of conditions in conjunction with obesity has been coined metabolic syndrome and substantially increases morbidity and mortality.

The above-reviewed factors are quintessential to understanding how to treat this chronic disease. Previously, healthcare professionals have struggled with understanding these known causes of obesity. These deficiencies have led to missed opportunities and failure to educate patients on up-to-date treatment options for chronic obesity.