Obesity: Diagnosis and Treatment

Diagnosis

A diagnosis of obesity requires a complete history and physical examination, with special attention to medications, herbal remedies, nutritional and exercise history, risk factors for coronary artery disease, and family history of thyroid and cardiac diseases.

BMI calculation is commonly used to estimate the severity of overweight.

Anthropometric measures also include waist circumference, waist–to–hip circumference ratio, and body–fat determination, which is based on skin–fold thickness or bioimpedance.

Laboratory testing includes fasting glucose and insulin concentration, thyroid–stimulating hormone and free T4 hormone levels, renal function, lipid panel, complete blood count (CBC), and aspartate aminotransferase (AST) to screen for hepatic steatosis.

Treatment

The therapeutic essentials for treating obesity are diet, exercise, and lifestyle modification that reduce energy intake and increase energy expenditure. Nutritional interventions are discussed below. Physical activity helps to retain lean body mass and may better prepare patients to keep weight off after the initial loss,¹ in comparison with food restriction alone.

Pharmocotherapy  

Several medical therapies are available. However, long–term results of pharmacotherapy are only moderate, and weight is regained once the patient discontinues the medications.² Recent evidence suggests that a combination of pharmacotherapy and behavior therapy achieves better results than either modality used alone.³

Medications that are commonly used (but not necessarily recommended) include:

Appetite suppressants. Examples are sibutramine, phentermine, benzphetamine, phendimetrazine, and diethylpropion.

Orlistat. This gastric lipase inhibitor decreases the absorption of dietary fat. However, when using this medicine it is necessary to supplement diet with fat–soluble vitamins and phytonutrients.

Surgery

Bariatric surgery has been used successfully in morbidly obese patients (BMI >40). Gastric bypass and banding are the most frequently used surgeries. Complications such as nutrient malabsorption and infection are common and lead to the 1% to 2% mortality risk associated with these procedures.

Lifestyle Modification

Certain personality and behavioral factors are characteristic of those who succeed at maintaining weight loss. These factors include developing coping skills that prevent using food for comfort; increasing self–efficacy with respect to weight control⁴; engaging in high levels of physical activity (approximately 1 hour per day); choosing a low–calorie, low–fat diet; eating breakfast regularly; self–monitoring weight; and maintaining a consistent eating pattern through the 7–day week.⁵ The characteristic behaviors of those who keep weight off are documented and updated through the National Weight Control Registry, available at: http://www.nwcr.ws/.⁵

Dietary Supplements

Patients should be advised to avoid dietary supplements promoting weight loss. Reviews of their effectiveness indicate a lack of efficacy for chitosan, chromium picolinate, Garcinia cambogia, glucomannan, guar gum, hydroxy–methylbutyrate, plantago psyllium, pyruvate, yerba mate, and yohimbe.⁶ Ephedra–containing formulas have been found effective for weight control, particularly when combined with aspirin. However, the risk–to–benefit ratio of this combination is prohibitively high due to potential adverse cardiovascular effects of ephedra, as well as potential gastrointestinal damage caused by aspirin.