Obesity is a multifactorial disease involving complex interactions among genetic, metabolic, environmental, cultural, and psychosocial factors. Estimates from the 2003-2004 National Health and Nutrition Examination Survey (NHANES) indicate that 66.3% of the U.S. population is either overweight (body mass index [BMI] 25 to 29.9 kg/m2
) or obese (BMI ≥ 30 kg/m2
with significant increases in the overweight prevalence among children and adolescents, and obesity prevalence in men between 1999 and 2004.2
In the United States today, obesity has become a pandemic, the most common nutritional problem, the second most preventable cause of death, a significant contributor to increased health care costs, and a condition that lessens life expectancy and reduces quality of life across the lifespan.3
This medical condition is not limited to the United States, and the World Health Organization (WHO) has now deemed overnutrition to be a health concern.4
Nearly 2.3 billion adults will be overweight and more than 700 million will be obese by 2015 according to estimates by the WHO. Despite overweight and obesity once being regarded as a problem of affluent countries, the prevalence of these conditions is on the increase in low- and middle-income countries, especially in metropolitan areas.5
See Figure 38-1
for the estimated prevalence of obesity in several countries.
Obesity has been linked to a host of chronic disorders associated with heart disease, including type 2 diabetes, dyslipidemia, and hypertension.6
It is associated with deleterious effects on the heart and circulatory system, contributing to an increased risk of arrhythmia, sudden death, congestive heart failure, and ischemic heart disease.7
Moreover, several physiologic parameters that affect cardiovascular risk factors are associated with obesity, such as lipoprotein oxidizability, arterial blood pressure, hemostatic or fibrinolytic abnormalities, and C-reactive protein, a vascular inflammatory marker.9
Obesity was established as a major risk factor for coronary heart disease (CHD) in 1998.
In the midst of the mounting evidence demonstrating the deleterious effects of obesity on health in general, and on the cardiovascular system in particular, research has demonstrated numerous benefits to health by as little as 5% to 10% reduction in initial weight.6
However, survey data show that 33% of men and 46% of women are attempting to lose and maintain weight but approximately only 20% are using a combination of reduced caloric intake and at least 150 minutes of weekly physical activity during leisure time to achieve weight loss.11
These facts highlight the importance of identifying the patient at risk and implementing an early treatment course that may prevent the development of obesity.
This major health problem began to receive increasing attention from the scientific community in the mid-1990s. Indeed, in 1997, a paper was published recognizing obesity as a chronic disease.12
The work of several organizations and policymaking groups helped draw attention to obesity as a health concern; for example, the Institute of Medicine published criteria for evaluating weight-management programs and other organizations published guidelines for treatment.13
In 1998, the National Heart, Lung, and Blood Institute (NHLBI) issued the Evidence report,15
which provided empirically based guidelines for the identification, evaluation, and treatment of overweight and obesity in adults. The guidelines are being updated by the NHLBI in 2008. Today, other organizations are becoming involved in this increasing public health concern. America on the Move is a national nonprofit online organization whose goal is to improve the health of Americans by advocating small changes in eating and physical activity routines to promote weight loss or cessation of weight gain. This organization offers free web-based programs and tools to individuals, groups, and communities to encourage changes like decreasing daily caloric intake by 100 cal and increasing daily physical activity by 2,000 steps.16
On the international level, the WHO began addressing the issue through the International Obesity Task Force.17
However, despite all the attention given to this serious public health problem, this problem is not being addressed by clinicians or policymakers to the extent that previous health threats, such as the use of tobacco, have been addressed. When patients’ visits to their family physicians were observed, only one in four received any nutritional counseling.18
Health care professionals can help slow the trend of excess weight by educating and counseling their patients about maintaining a healthy weight and how to use healthy lifestyle measures to reduce excess weight.
This chapter draws on the growing volume of empirical literature pertaining to obesity and the evidence-based guidelines to provide an overview of treatment of overweight and obesity. It begins with a review of the process of identification and evaluation of a patient’s risk status and the selection of appropriate treatment. The major components of treatment are covered: lifestyle modification, which includes dietary, exercise, and behavioral therapy; drug therapy; and surgical therapy. Finally, maintenance strategies to enhance long-term adherence to the lifestyle changes that facilitated the weight loss are reviewed.
Baseline assessment of the cardiac patient includes the BMI, waist circumference, and cardiovascular risk profile, as well as noncardiovascular conditions, for example, sleep apnea, OA, gallstones, and gynecologic abnormalities. These factors need to be evaluated so that obesity is treated in the context of the patient’s risk profile and existence of comorbid conditions.7
Weight loss frequently ameliorates risks by reducing blood pressure and triglycerides, as well as lessens the impact of other comorbid conditions. Therefore, risk factors should be addressed through weight loss treatment. The NHLBI Evidence report15
includes an algorithm that addresses the treatment decisions based on that assessment (Fig. 38-2
). This algorithm is focused on weight-related assessment and treatment and does not include evaluation for other disorders for which the patient may be seeing a health care provider. As noted in Figure 38-2
, if the patient’s BMI and waist circumference are in the normal range, these parameters should be measured again in 2 years. For the patient who is of normal weight, brief counseling about prevention of future weight gain should be provided. Knowing that weight gain can be expected from most patients, maintenance of weight is a positive outcome and patients should receive reinforcement for maintaining a healthy weight.
For the patient whose parameters are not normal, assessment needs to include the patient’s history, including prior excess weight or weight fluctuations. If not done previously, a physical examination and laboratory measurements to assess lipid profile, glucose level, and related parameters need to be performed. The provider needs to identify existing cardiovascular disease and the presence of possible end-organ damage.
▪ Figure 38-2 Treatment algorithm. This algorithm applies only to the assessment for overweight and obesity and subsequent decisions based on that assessment. It does not include any initial overall assessment for cardiovascular risk factors or diseases that are indicated. (Adapted from National Heart, Lung, and Blood Institute, Obesity Education Initiative Expert Panel on the Identification Evaluation and Treatment of Overweight and Obesity. . Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults: The evidence report. Bethesda, MD: National Institutes of Health.)
Eating and Physical Activity Patterns
A nutritional and physical activity assessment provides additional information that can be used in the treatment plan. This can be done by having the patient complete a 3-day food and activity diary, which should include two work and one nonwork or leisuretype days. When using a 3-day food and activity diary, the patient needs to be instructed on completion of the diary and the details to be included (e.g., exact amount of food eaten and inclusion of recipes or package labels if the food is unusual). Food frequency, 24-hour dietary recalls and activity questionnaires are another means of assessing past year food consumption or current level of physical activity.37
During the 24-hour dietary recall, the trained interviewer asks the patient to recall every food and drink that was consumed in the previous 24 hours. The interview may be conducted either in-person or via the telephone, is usually unannounced, and typically takes 20 to 30 minutes to complete; this assessment tool may be more commonly used in a research setting.37
Before considering treatment options, the patient’s motivation for engaging in weight loss treatment needs to be assessed. Embarking on a weight loss and maintenance program requires a commitment to a change in lifestyle and an investment of resources by the patient and the provider. Moreover, the change is not for a limited time, but rather lifelong. Factors to consider in the initial assessment include the patient’s attitude toward weight loss, prior treatment failures and successes, support system, comprehension of risk posed by weight status, readiness to initiate lifestyle changes,40
self-efficacy for achieving weight loss,41
time commitment, barriers to behavior change,42
and financial issues if the treatment is not covered by insurance. Adverse medical events have been reported as a motivating trigger for initiating weight loss efforts and are in fact associated with greater weight loss and less regain, suggesting that health care professionals might use these occasions as an opportunity to introduce the topic of weight management.43
Individuals experiencing major life events, such as a relocation, change in marital status, and family illness, may find it better to delay initiating a weight loss program until they can focus on the behavior changes required. Those individuals with significant anxiety, depression, or eating disorders (e.g., binge eating or bulimia) may need to be treated for these conditions before initiating a weight loss program, even if health care professionals conduct the program. Patients with eating disorders are best served by a referral to a specialist.44
For the unmotivated patient, the provider needs to review the risks of excess weight and the benefits of initiating treatment and discuss how this treatment may be different and how the patient will be assisted. If the patient remains uninterested in treatment, the provider needs to address coexisting risk factors and initiate management of these, including further weight gain prevention. When the patient is ambivalent about making lifestyle change or initiating a weight loss program, motivational interviewing (MI) strategies, also referred to as reflective listening, can be used.45
This approach, which will be discussed in more detail later in this chapter, requires training of the clinician. Once the assessment has been completed, the treatment plan needs to be considered and discussed with the patient.
Provider Assessment of Patient’s Objectives
The manner and attitude of the health care professional when addressing the patient’s obesity and weight management may be an important determinant of the patient’s receptivity. There is some evidence that health care professionals doubt a patient’s motivation or ability to make lifestyle changes and thus might be nonsupportive of the patient’s goals.46
The patient needs to define the problem and the clinician needs to be nonjudgmental in discussing the behavior and the weight problem. When discussing treatment options with the patient, conveying an empathetic understanding of the challenges that come with the long-term lifestyle changes is important. Finally, eliciting the patient’s objective for the treatment and mutually agreeing on a plan of action for the short- and long term will enhance the probability of a positive outcome.47
Environmental Barriers to Weight Loss
Environmental obstacles exist partially as a result of our technologically advanced society where reduced energy expenditure in day-to-day life and increased access to high-fat, high-calorie convenience food in larger portion sizes are common.49
In addition, ethnic minorities might be particularly affected by the living environment. For example, neighborhoods in New Orleans with 80% Black residents had 2.4 fast-food restaurants per square mile compared to 1.5 fast-food restaurants per square mile in communities with only 20% Black individuals. Black neighborhoods had access to six more fast-food restaurants than did mostly White neighborhoods when comparing communities of similar size.50
Recent findings revealed that persons who live in areas with a higher number of fast-food restaurants had a higher BMI compared with persons who live in areas with a higher number of full-service restaurants.51