Managing Adult Obesity Lifestyle

According to the Centers for Disease Control and Prevention (CDC) Behavioral Risk Factor Surveillance System (BRFSS), self-reported prevalence of obesity among US adults increased from 12% in 1991 to 18% in 1998. [8] Data from the 1988 to 1994 National Health and Nutrition Examination Survey (NHANES) suggested that 63% of men and 55% of women were overweight. [9] More recent (1999) data from NHANES IV found that obesity rates among adult Americans increased from 15% in 1980 to 27% in 1999.

America regrettably is a world leader in the epidemic of overweight and obesity, but it does not stand alone. Surveys in Europe and the Far East show that over the last 10-20 years, rates of overweight and obesity have increased by 1.5 to 2.0 fold in many countries.  Recent reports from Hong Kong and the Republic of China suggest an emerging epidemic of obesity which is directly related to the increasing dietary fat and calories.

The magnitude of the increased prevalence of obesity in the US between 1991 and 1998 varies by region. It ranges from 31.9% in the mid-Atlantic to 67.2% in the south Atlantic regions. The increased prevalence also varies considerably by state ranging from 11.3% in Delaware to 101.8% for Georgia.  In another survey, Missouri ranked 2nd in overweight. [11] The magnitude of the increase is greatest in 18 to 29 year olds (7.1% to 12.1%), those with some college education (10.6% to 17.8%), and those of Hispanic ethnicity (11.6% to 20.8%).

Although attempts to lose weight are common in the United States (36.2% of the population in the 1998 BRFSS were trying to lose weight), the prevalence of overweight and obesity continues to increase. [12] An additional 55.6% of respondents in the 1998 BRFSS indicated they were trying to maintain their current bodyweight. One third of the respondents indicated they were consuming fewer calories and fat, and 60% indicated they were using exercise to assist with weight control. However, other studies indicate that most persons attempting to lose weight through exercise and diet are neither doing enough exercise nor are they using sound dietary principles.

The annual economic costs of obesity are estimated to be > 70 billion dollars.  In spite of the health and economic burden of obesity, studies show that health professionals do not consistently advise overweight and obese patients that they should lose weight.  In fact, the 200 BRFSS revealed that only 14.5% of patients were counseled about weight whether it was to lose, gain, or maintain bodyweight.

Thus, there is clearly a global epidemic of overweight and obesity. It can be estimated that, at the present rate of increasing prevalence of obesity, by the year 2030, 90% of US adults will be obese! We think it’s time to seriously address this issue and establish a nationwide campaign to help American adults achieve and maintain healthy body weights.

Overweight and obesity are risk factors for numerous chronic diseases. After statistically accounting for tobacco use, an estimated 325,000 deaths each year are attributable to obesity (body mass index [BMI] > 30.0).  Several studies confirm a strong relationship between BMI and mortality in US adult men and women.

Calle et al. reported that the lowest risk for mortality in a 14 year follow-up of a large cohort of 457,785 men and 588,369 women was at a BMI of 23.5 to 24.9 in men and 22.0 to 23.4 in women.  The relative risk for mortality in the heaviest BMI group ( > 40) was 2.58 in men and 2.0 for women compared to those in the group between 23.5 and 24.9 in men and 22.0 and 23.4 in women. A high body mass index was most predictive of death from coronary vascular disease (CVD), especially in men (relative risk = 2.90). The CVD risk of overweight and obesity was greater in Caucasians than African-Americans.

Similar findings in large cohorts were reported previously by Manson et al. (women) and Stevens et al. (men and women) although the nadir of their curves was somewhat lower at between 19 and 22 BMI.  In the study by Manson et al., the lowest mortality over 16 years was observed among women who weighed at least 15% less than the U.S. average for women of similar age and among those whose weight had remained stable since early adulthood.

In a 26-year study of 26,000 white Seventh Day Adventist women who never smoked and were healthy at baseline, the relative risk of death was lowest for 30-54 year old women at a BMI between 21.3 to 22.9.  For women between 55 and 74 years of age, the lowest relative risk was found at a BMI between 23.0 to 24.8.

A recent ten-year follow-up report of middle aged women (Harvard Nurses’ Health Study) and men (Health Professionals Follow-up Study) looked at the impact of overweight on the risk of developing common chronic diseases during a 10-year period.  The most significant and startling finding from this study was that men and women with a BMI over 35 were approximately 20 times more likely to develop diabetes mellitus (DM) than their same-sex peers with a BMI between 18.5 and 24.9. Additionally, women and men who were not obese, but were overweight (BMI’s between 25 and 29.9) were at 1.5 to 2.0 fold greater risk of developing gallstones, hypertension, high cholesterol, colon cancer, heart disease, or stroke. The results of another study also found that persons with coronary artery disease (CAD) and a BMI greater than 35 had a seven-fold increased risk for mortality compared to persons with CAD and a BMI less than 25.

Chronic diseases are the leading causes of mortality and morbidity in the United States and they pose a tremendous public health challenge. Clearly, one of the most well-established risk factors for chronic diseases is overweight and obesity. In fact, a recent report from the RAND Corporation found that after controlling for demographics, obesity was associated with more chronic conditions and worse physical health-related quality of life than tobacco use or poverty.

Prospective epidemiological studies have shown that weight loss, weight gain, and weight cycling (frequent episodes of weight loss and regain) are all related to increased mortality compared with a stable weight.  Since unintentional weight loss is often associated with symptomatic disease, it is apparent why mortality might be increased. Weight gain clearly increases the prevalence of several risk factors for chronic disease and, thereby, would be expected to increase morbidity and mortality. Recent studies also have demonstrated that weight cycling is associated with increased health risks.  Many epidemiological studies of weight loss have not adequately addressed these issues creating confusion among the public. It is the author’s perspective that the evidence regarding sustained weight loss in adulthood clearly supports the health benefits of intentional weight loss and maintenance.

Numerous studies show that weight loss, even if only 5-10%, significantly improves lipoproteins,  hypertension,  DM and insulin resistance, risk for osteoarthritis and it’s symptoms,  risk for selected cancers,  and other risk factors for chronic diseases.

A recent study from Finland of nearly 500 men and women at risk for type 2 DM who were randomized to intensive lifestyle modifications or standard care found a 58% reduction in new cases of DM over three years.  None of the subjects who achieved all five study goals (weight loss of 5-10%, 30-45 minutes of physical activity, 4-5 days per week, < 30% fat calorie intake, < 10% saturated fat calorie intake, and 15 grams of fiber per 1000 calories) developed DM. This study was a multifactorial design, but included common lifestyle changes (i.e., increased physical activity and a 30% or less fat diet with increased fiber) aimed at weight loss. Clearly even small amounts of weight loss can significantly improve risk factors for CVD and other chronic diseases. However, it is not clear whether the benefits of moderate weight loss are sustained long term. One basic problem has been the inability to successfully maintain significant long-term weight loss. The Finnish study which was the first published randomized clinical trial of diabetes prevention through lifestyle changes suggests that sustained modest weight losses of 5% of bodyweight can indeed reduce the risk of developing a chronic disease.

Several recent large prospective studies suggest that intentional weight loss is associated with decreased mortality.  One study of 43,457 women found that any amount of intentional weight loss resulted in health benefits.  In this study, women who intentionally lost weight had a 40-50% decrease in deaths from obesity-related cancers and a 30-40% decrease in death from type 2 DM. Another study of 49,337 men reported a 32-36% decline in death from DM among men with health problems who intentionally lost weight.

It is beyond the scope of this case to thoroughly review and discuss the benefits of intentional weight loss. However, it seems clear that numerous health benefits are potentially derived from weight loss, particularly when it is intentional and sustained over the long term. Throughout the management plan for the case study presented in this paper, additional evidence will be provided for the health benefits associated with intentional weight loss.

Etiology of Obesity

Since the 1970′s, Americans have become more health conscious. Blood pressure levels are lower as are cholesterol levels and CVD mortality has decreased by more than half. Many experts suggest that at least half of the decline in heart attacks is due to improved lifestyles among Americans. In addition, low fat foods are abundant, health club memberships are up considerably, and athletic gear manufacturing is a multibillion-dollar industry.

However, overweight and obesity rates have continued to increase during this expansion of health-related industries. What are the causes for this apparent paradox of an increasingly overweight populace in the face of increasing attention to health issues? Katherine Flegal, PhD, an epidemiologist for the National Center for Health Statistics, (NCHS) states that “the data are confusing, but the causes of the obesity epidemic most likely are too much food and too little physical activity.”

Although there have been landmark discoveries in the past decade of genetic contributions to obesity such as the OB gene in mice, leptin, uncoupling proteins, and neuropeptides, these findings cannot explain the obesity epidemic. Human genes certainly have not changed dramatically in just 8 years from 1991-1998, a period over which there was a 50% rise in the prevalence of obesity. Studies suggest that 25% to 70% of obesity can be explained by genetics. [39] [40] Studies of twins suggest inheritance explains 25% to 40% of inter-individual differences in obesity. A few single gene defects have been discovered such as congenital leptin deficiency or congenital leptin receptor deficiency.

However, in most cases, genes involved in weight gain do not directly cause obesity but rather they increase the susceptibility to fat gain in subjects exposed to an environment characterized by an abundance of food and limited physical activity. Hill and Peters and Hill and Melanson argue that “the culprit is an environment which promotes behaviors that cause obesity.”  The bottom line appears to be that some individuals with a genetic tendency may avoid obesity by maintaining a pattern of healthy eating and physical activity behaviors.

Thus, obesity is a complex, multifactorial chronic disease. Simply stated, bodyweight depends upon the balance between calories consumed and calories expended. This balance depends largely on genetic make-up, level of physical activity, and resting energy expenditure. If more calories are consumed than expended, the excess calories are stored as fat in the form of adipocytes. The more compelling issue, however, is why do some people store more calories than they expend? Is it because overweight people simply eat too much and engage in too little physical activity? Or are some persons predestined by their inheritance to be overweight or obese irrespective of their environment and personal habits?

Scientists have identified several dozen genes that appear to be connected to human obesity. In 1994, the OB gene was discovered.  The OB gene is responsible for the production of leptin in adipocytes, a hormone which appears to decrease appetite and stimulates metabolism. In humans, it was found that most obese persons have high levels of leptin due to their high levels of body fat.  As a result, low levels of leptin due to an absence of the OB gene does not appear to be a common cause of obesity. Thus, many scientists believe that some obese humans are “leptin-resistant” in much the same way persons with type 2 DM are “insulin-resistant.”

American society has evolved into an environment which facilitates weight gain. Studies show that only approximately 20% of Americans achieve the minimum public health goal of 30 minutes of moderate intensity physical activity on most days of the week.  This percentage has essentially been the same for nearly three decades. However, the population has increased by ~60 million during that same period. Thus, the absolute number of Americans achieving 30 minutes or more of physical activity has increased from 44 million in 1975 to 56 million in 2000, resulting in 48 million more sedentary or irregularly active persons.

Food is readily available and in “super-sized” portions. In fact, a study of the ecological basis of the increased US prevalence of obesity estimated that food availability has increased 15% since the mid-1970′s. [2] Physical activity has been all but “engineered” out of our vocational and leisure-time pursuits. This environment facilitates a positive energy balance by promoting overeating and discouraging physical activity. As an example of the cultural pressure towards a positive energy balance, Yanovski et al. reported that the average American gains 1-2 lbs during the yearly holiday season. [47] Over ten years, this amounts to a 10-20 lb weight gain.

The US also is a leading innovator of passive entertainment. Television viewing, for example, has been shown to be positively related to obesity and the development of diabetes.  The average adult American spends half his or her leisure time watching television. Combine this with jobs that involve very little physical activity, plus video games, computing, gambling, etc., and it becomes apparent why daily caloric expenditure has declined precipitously since the 1950′s and 60′s.

Other factors that contribute to the obesity epidemic include the high energy density and fat content of processed foods, increased prevalence of eating out, particularly at fast food restaurants, availability of food in gasoline stations, vending machines, and in discount and department stores. Essentially, the US culture seems to have created an environment of “sedentarism and obsessive-compulsive eating.”

It is beyond the scope of this case to review in detail the causes of obesity. However, the case below will illustrate that obesity can be successfully treated through lifestyle changes. This case will demonstrate further the environmental factors which increase susceptibility to obesity.

Management Plan

It was decided, after thorough discussion of the benefits, risks, and purposes of the procedure with the patient, that a cardiac catheterization should be done. This was performed and revealed a 50% non-calcified lesion in her proximal right coronary artery and a 30-40% lesion in her mid-LAD with some plaqueing throughout the coronary tree, but no other significant stenoses. Left ventricular pressures were at the upper limits of normal and her ejection fraction was calculated to be 67%.

After discussion with the patient and family, it was decided to treat her with a trial of aggressive medical and lifestyle therapy. Due to the enormous body of literature supporting the role of statin (HMG Co-A Reductase Inhibitors) therapy in stabilizing vulnerable plaques and reducing the risk of first heart attacks, she was placed on 20 milligrams of Pravastatin (Pravachol®).  She also was prescribed a baby aspirin (81 mg/day) for anti-platelet therapy.

It was decided to attempt to treat her metabolic disorders initially with lifestyle changes which is clearly supported by several national and association guidelines.  She was referred to a Registered Clinical Exercise Physiologist and a Registered Clinical Dietitian for consultations and guidance in implementing a sound weight loss plan. A high fiber, low fat, and low calorie diet and a three month supervised exercise program were prescribed. Goals of 30-45 minutes of aerobic exercise, 4-5 days per week, stretching and weight training for 20-30 minutes, 2-3 days per week, and a daily caloric intake target of 1400 calories per day to produce a weight loss of 0.5 to 1.5 lbs per week were established.

A Stages of Change evaluation revealed she was ready to take action to improve her health through increasing physical activity, improving her diet, and losing bodyweight.

Diet Plan

A low fat, low calorie, and high fiber diet was prescribed. Emphasis was placed on both short-term realistic goals (0.5 to 1.5 lbs of fat loss per week) and developing a foundation for long-term maintenance of a healthy, palatable diet. Retrospective studies suggest that, long-term, low fat, high complex carbohydrate dietary patterns are most effective for weight loss and maintenance.

Based on measured resting energy expenditure adjusted for light physical activity, and estimated and anticipated caloric expenditure during exercise and increased lifestyle physical activity (PA) after 1-2 months (1100 in exercise and 800 in increased lifestyle PA), a 1400 kilocalorie diet was prescribed. In light of the type 2 DM, particular attention was given to meal planning, high fiber, and low glycemic index foods. A macronutrient distribution of 25% protein, 55% carbohydrate, and 20% fat was prescribed. Since she does not consume alcohol, this was not an issue with respect to calorie distribution.

The caloric distribution was prescribed to be 350 protein (~88 grams), 770 carbohydrate (~192 grams), and 280 fat (~31 grams). A slightly increased dietary protein percentage was suggested to compensate for increased protein needs when sedentary adults initiate a regular exercise program.

Mrs. Jones was advised to consume these calories in three meals and two snacks per day including, in particular, a high fiber breakfast. In addition, it was recommended that she try to consume 75% of calories before 6:00 pm. She also was seen by a certified diabetes educator (CDE) for education about type 2 DM and self-monitoring of blood glucose.

Several recent studies have shown the safety and efficacy of the DASH (Dietary Approaches to Stop Hypertension) Diet on lowering blood pressure in adult men and women of varied ethnicity with Stage 1 hypertension or upper normal levels. [65] [66] [67] [68] One study of the DASH Diet showed that a low sodium diet of 1500 milligrams per day optimized the efficacy of this diet which on average is 26% fat and 6% saturated fat with 143 mgs cholesterol intake per day.

Key components of the DASH diet are clearly compatible with a hypoglycemic diet and include 7-9 servings of fruits and vegetables, 6-11 whole grain servings, 4-6 ounces of lean animal foods, and 2-3 low fat (1% or less) dairy product servings per day.

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