Chapter 9 Diet, Exercise, and Obesity
Clinical Case Problem 1 A 45-Year-Old Man Weighing 320 Pounds and Complaining of Fatigue
Select the best answer to the following questions
1. Assuming that his total energy expenditure is 2300 kcal/day and he does, in fact, stick to his 1800 kcal/day diet, how long will it take for him to reach his ideal weight?
2. How is obesity generally defined?
3. Which of the following statements is (are) true regarding obesity?
4. What is the overall prevalence of obesity in the United States?
5. Which of the following conditions is (are) most clearly linked with obesity?
6. The use of severe calorie-restricted diets (800 kcal/day) has been responsible for many deaths. What is the most common cause of death in these cases?
7. What is the percentage of individuals in the United States who achieve levels of vigorous leisure-time activity of more than 10 minutes at least three times per week?
8. Which of the following statements is (are) true regarding the use of anorexic drugs?
9. Which of the following is (are) advocated as part of a weight loss program?
10. The practical management of weight loss by the family physician should involve which of the following?
11. Which of the following recommendations should the family physician make in addition to the practical management components chosen in question 10?
Answers
1. e. One pound of fat is equal to 3500 kcal. Therefore, if his total energy expenditure is 2300 kcal/day and the patient is taking in only 1800 kcal/day (the recommended difference in a weight loss program between energy expenditure and energy intake is 500 kcal), his energy deficit is 500 kcal/day. His excess weight above ideal body weight is 150 pounds. This 150 pounds is equal to 525,000 kcal. The corresponding time to lose this number of calories is 1050 days (2.87 years).
2. d. The National Institutes of Health defines obesity as a BMI of 30 kg/m2 or more, and it defines overweight as a BMI of between 25 and 29.9 kg/m2. BMI is calculated by multiplying the weight in pounds by 703 and dividing the product by the height in inches squared, that is, BMI = (weight in pounds × 703) ÷ (height in inches)2.
3. e. Obesity is a major public health issue. There is a certain stigmatization to the diagnosis of obesity not present in many other conditions. Some authorities suggest that we should label obesity as essential obesity in the same way that we label hypertension as essential hypertension. The comparison between hypertension and obesity does not end there. Obesity is a major risk factor for coronary artery disease and other cardiovascular conditions, including hypertension, congestive heart failure, cardiomyopathy, and angina pectoris.
4. d. The overall prevalence of obesity in the U.S. adult population is approximately 34% (BMI = 30), an astounding increase from approximately 15% in 1976. Results from the 2008 National Health and Nutrition Examination Survey, using measured heights and weights, indicate that an estimated 17% of children and adolescents aged 2 to 19 years are overweight. Overweight increased from 7.2% to 13.9% among 2- to 5-year-olds and from 11% to 19% among 6- to 11-year-olds between 1988-1994 and 2008. Among adolescents aged 12 to 19 years, overweight increased from 11% to 17% during the same period. In certain groups, such as the Pima Indians, the prevalence of obesity is 50%. A higher prevalence of obesity occurs in those individuals in the lowest socioeconomic groups; the prevalence does, in fact, decrease as socioeconomic status increases. Combining the categories of overweight (BMI 25 to 29.9) at 32% and obesity (BMI = 30) at 34%, fully 66% of the adult population in the United States is carrying excess weight.
5. e. Of the conditions already postulated as linked with obesity, the strongest associations are between obesity and hypertension and obesity and diabetes. The other conditions listed previously are also linked to obesity. Moreover, there is strong evidence that weight loss in an obese individual reduces blood pressure and hemoglobin Alc, triglyceride, low-density lipoprotein, and total cholesterol levels, and it increases high-density lipoprotein levels.
6. a. The most common cause of death reported among patients who are on severe calorie-restricted diets is sudden cardiac death as a result of ventricular arrhythmias or dysrhythmias.
7. b. Recommended weekly physical activity is defined as moderate-intensity activities (brisk walking, bicycling, vacuuming, gardening, or anything that causes small increases in breathing or heart rate) for at least 30 minutes per day, at least 5 days per week, or vigorous-intensity activities (running, aerobics, heavy yard work, or anything else that causes large increases in breathing or heart rate) for at least 20 minutes per day, at least 3 days per week, or both. This can often be accomplished through lifestyle activities (i.e., household, transportation, or leisure-time activities), which means almost all patients should be able to incorporate recommended levels of physical activities in their lifestyle.
8. e. Although short-term weight loss is enhanced by these agents, long-term studies demonstrate that most patients suffer a rebound effect and actually may end up even heavier. In addition, hypertension, stroke, and renal failures have been documented in patients using anorexic drugs. These medications can be classified as catecholaminergic or serotonergic: