Weight Loss Diets & Supplements Exam Prep Chapter 10

Chapter 10

Weight Loss Drugs, Commercial and Fad Diets, Supplements, and Surgery

Learning Outcomes

Upon successful completion of this chapter, students should be able to:

1. Characterize a good weight-loss drug and summarize the effectiveness of drug therapy for weight management.
2. For the weight management drugs discussed in this chapter, describe their potential for promoting weight loss and typical adverse effects.
3. List the physiological effects of caloric reduction and summarize the effectiveness of very-low-calorie and popular low-calorie diets for weight management.
4. Discuss the factors that a consumer should consider when evaluating a low-calorie diet.
5. Define dietary supplement and describe how dietary supplements are regulated in the U.S.
6. For the dietary supplements discussed in this chapter, describe their potential for promoting weight loss and typical adverse effects.
7. Compare and contrast the most common bariatric surgery procedures, including their benefits and potential complications.
8. Evaluate the effectiveness of liposuction as a treatment for obesity.

Chapter Outline/Summary

1. Weight-loss drugs
   1. Characteristics of a good weight-loss drug:

In reviewing drugs for the treatment of obesity, the Food and Drug Administration (FDA) considers potential risks of the drug, as compared to the benefits it offers, potential for abuse, potential to reduce weight at least 5% more than a placebo or to help 35% of users lose 5% or more of baseline weight, and potential to reduce comorbidities. Generally, a user should have a BMI of 30 or a BMI of 27 with disease risk factors.

• 1. Drugs that reduce energy intake:

Anorexiant drugs suppress appetite and promote satiety and act on the catecholaminergic system, the serotonergic system or both. These include phentermine and related drugs, lorcaserin, and combination drugs. All have side effects.

• 1. Drugs that reduce fat absorption:

Orlistat, available by prescription and over-the-counter in a lower dose, is the only drug that reduces fat absorption. It helps to reduce some of the comorbidities of obesity, but has gastrointestinal side effects.

• 1. Diabetic medications for weight management:

Metformin, pramlintide, and glucagon-like peptide-1 agonists are medications prescribed for the treatment of diabetes that may also have weight-reducing effects.

• 1. How effective is drug therapy:

Most obese individuals who take weight-reducing drugs lose between 5-10% of their initial body weight during drug therapy. Drugs may also reduce the comorbidities associated with obesity. Individuals who are most successful in losing weight also make lifestyle modifications – paying closer attention to the quantity of food ingested and making an effort to increase physical activity.

1. Low-calorie diets
   1. Physiological effects of caloric reduction:

When daily caloric intake falls below approximately 1,200 kcals, physiological changes occur – energy expenditure decreases, hunger increases, and the individual may experience weakness, dizziness, constipation, and other unpleasant effects. When caloric intake drops below 1,000 kcal/day, gallstones, gout, and sudden cardiac death are more serious side effects.

• 1. What are very-low-calorie diets:

Very-low-calorie diets (VLCDs) are medically supervised diets that provide ample protein but no more than 800 kcal/day. Nutrients are obtained from bars, soups, or liquid formulation prepared from a powder mixed with water. Most VLCDs last for 12 weeks, followed by 12-14 weeks of refeeding with regular foods. These diets have positive health outcomes and can result in reductions of 15-25% of initial weight. However, a substantial amount of weight is regained when the diet ends.

• 1. How effective are popular low-calorie diets:

Popular low-calorie diets provide 800-1500 kcal/day from various nutrient combinations, some of which use special foods. Commercial weight-loss programs such as Weight Watchers and Nutrisystem are additional examples of these diets. Other than Weight Watchers, popular low-calorie diets are generally not systematically evaluated and have poor long-term outcomes. Depending on the combination of nutrients recommended by the diet, they can have unhealthy side effects.

• 1. Consumer protection from fraudulent low-calorie diet programs:

The Federal Trade Commission and the Partnership for Healthy Weight Management developed Voluntary Guidelines for Providers of Weight Loss Products or Services, which can help consumers evaluate weight-loss programs.

1. Weight-loss dietary supplements
   1. Regulation of dietary supplements:

The FDA regulates dietary supplements, although its oversight is constrained by provisions of the Dietary Supplement Health and Education Act. U.S. manufactured dietary supplements do not follow standard formulary. Dietary supplements are not drugs and therefore cannot claim to treat specific diseases or conditions.

• 1. Supplements that claim to promote weight loss:

Several dietary supplements claim to promote weight loss, including caffeine, chromium, soluble fibers, garcinia cambogia, chitosan, pyruvate, dieter’s teas, and fat burners. Only pyruvate and soluble fibers have any evidence that they promote small weight losses. Adverse effects of dietary supplements can be significant.

• 1. Avoiding fraudulent products and practices:

Consumers need to be wary of claims made by dietary supplement manufacturers. The best way to assure that a supplement contains what the label states is to look for the U.S. Pharmacopeia (USP) mark. The FDA and the National Institutes of Health Office of Dietary Supplements publish information about supplements.

1. Weight-loss surgery
   1. Who should (and who should not) have bariatric surgery:

Bariatric surgery is generally used only after other weight-loss methods fail. Surgery should be reserved for the very obese (BMI > 40) or the obese (BMI 35-39) who have comorbidities. Patients should be screened for their readiness to make dietary and activity modification necessary for the success of bariatric surgery.

• 1. The most common bariatric procedures:

Three procedures are most commonly performed: gastric bypass (Roux-en-Y gastric bypass), which has the greatest potential for weight loss; laparoscopic adjustable gastric banding, which results in the smallest weight losses; and laparoscopic sleeve gastrectomy, whose effectiveness falls between the other two.

• 1. How safe and effective is bariatric surgery:

Bariatric surgery has been called the only treatment for severe obesity resulting in significant weight loss that is maintainable. Average weight losses of 40-50% of excess body weight are common. Comorbidities of obesity almost always improve. The patient’s readiness, willingness, and ability to change are crucial predictors of surgery success. Surgical complications and mortality rates for bariatric surgery are low.

1. Localized fat reduction
   1. Cellulite:

Cellulite is fat tissue that has projected into the dermis, which gives it a dimpled appearance. Cellulite is far more common in women than men. Herbal treatments, creams, and laser therapy have a modest impact on cellulite’s appearance.

• 1. Liposuction as a treatment for obesity:

Liposuction is the localized removal of superficial fat tissue with cannulae as fat tissue is broken up with liquids, ultrasound, and lasers. Serious complications can result: pulmonary embolism, fat embolism, necrotizing fasciitis, and burns. Although large amounts of fat can be removed with liposuction, fat will return if behavior is not changed, and obesity cannot be reversed with liposuction alone.

1. Conclusion:

While the approaches to weight loss in this chapter suggest that pills, diets, dietary supplements, or surgery alone can effectively treat obesity in the absence of lifestyle change, that is not the case. Unless weight loss is needed to maintain health, a better approach is to focus on behaviors that promote health, good attitudes toward food and activity and prevention of further weight gain.

Suggested Activities and Applications

Application 10.1 Weight-Loss Drugs

For this application, students will read a case study about John, an accountant who is 6 feet tall and weighs 250 lb. John and his doctor have agreed that he needs to lose some weight to help normalize his blood glucose and blood pressure. John has tried exercise but was unable to remain compliant with an exercise program. John’s doctor is preparing to prescribe Xenical.

Students could be required to work through this case study, individually or in groups, before the instructor presents a lecture about weight-loss drugs. This will allow them to read about Xenical specifically and the FDA guidelines for approval and use of weight-loss medications in general. The instructor might even assign different drugs to different groups. Students will respond to these questions:

• Is John an appropriate candidate for a weight-loss drug? Yes. His BMI is >30, and he has two comorbidities: borderline hypertension and elevated glucose.
• What information should his physician provide about Xenical? His physician should inform him of the side effects (gas, bloating, fecal discharge) and how a lower-fat diet can help minimize these. He should also be told about the potential for weight loss, so he will have a realistic concept of what to expect.
• What kind of weight loss should John expect? An 11% weight loss is realistic, which could reduce John to a weight of around 223 lb and lower his BMI to 30-31.
• How could John improve the chance of losing more weight? Increasing his physical activity, even if not through formal exercise, could help him lose a bit more. In addition, he should pay attention to portion sizes and reduce the fat in his diet.

Application 10.2 Low-Calorie Diets

This application continues the case study about John. Students learn that John took Xenical for about a year, exercised a bit, and was careful about what he ate, and he was able to reduce his weight to 218 lb. at this point in the case study, John has stopped taking Xenical due to gastrointestinal side effects, and at the same time he has been dining out more and exercising less. A 30-lb weight regain has led John to follow a low-calorie diet recommended by a co-worker. He intends to eat 1,000 kcal/day with limited carbohydrates.

• Students are asked to design a 1,000 kcal/d day with only 20% of kcals from carbohydrates and at least 300 kcal from protein. Tip: students can use the Exchange System for this, as foods in Appendix C are categorized by their carbohydrate, fat, and protein content and their caloric value.
• Barriers to staying on such a diet: Students may note the quantity of food, lack of variety, difficulty dining out as barriers.

Application 10.3 Bariatric Surgery

The continuing case study about John now finds him weighing 370 lbs after a succession of diets, including a VLCD. He has arthritis in his knees, hypertension, and type 2 diabetes, and is embarrassed about his size. His physician has suggested bariatric surgery.

• Is John a good candidate for bariatric surgery? He meets the recommendations for body weight and comorbidities. He loves to eat, so he will need pre-surgery counseling and education to help him understand the food limitations associated with bariatric surgery.
• Estimate the excess weight John might lose from bariatric surgery. With good compliance after surgery, John could lose 40-50% of his excess weight. His excess weight is the difference between his current weight (370 lb) and what a height-weight table indicates as a healthy weight for a 6-foot man. If we make the assumption that he is of medium frame, the 1959 Metropolitan Desirable Weight table (Appendix A-2) suggests a weight range between 144-159 lb. The 1983 Metropolitan table (Appendix A-3) suggests 157-170 lb. Using 170 lb as his desirable weight, he is carrying 200 lb of excess weight (370 minus 170). Note that if he is large framed, his desirable weight could be 153-188. If he loses 40-50% of his excess weight, he could anticipate a weight loss of 80-100 lb.
• Students should pick one of the types of bariatric surgery and explain to John what he can expect postoperatively. The instructor could assign individuals or groups of students to the types of bariatric surgery covered in this chapter, so that a discussion of this question includes gastric bypass, lap-band surgery, and sleeve gastrectomy.
• What will John need to do to maximize the weight-loss potential of the type of bariatric surgery chosen/assigned? Failure to comply with a new way of eating is the most common reason that bariatric surgery is unsuccessful. John needs good nutrition information so that he includes sufficient fiber in his diet to slow food emptying from the pouch, and he needs to avoid empty calorie foods that empty quickly. He needs support to adopt a regular exercise and physical activity regimen.

Activity 10-1 Diet Book Review

Students are often intrigued with popular diet books, such as The Paleo Diet and The Zone. This assignment asks them to critique objectively the dietary advice contained in these books. Students can work individually or in groups. They should read the diet book and develop a brief written critique that includes:

(a) Summary of the diet program.

(b) The author’s justification for this approach to weight loss.

(c) An evaluation of the efficacy of the diet, based on scientific evidence.

(d) Assessment of potential benefits and harm from following such a diet program.

Chapter 10

Weight Loss Drugs, Commercial and Fad Diets, Supplements, and Surgery

Test Questions

True/False

1. The USDA did not approve any new weight loss medications between 1973 and 1996. (True/ False)

2. Weight loss drugs have been prescribed with increasing frequency in the United States. (True/ False)

3. Catecholaminergic drugs are like amphetamines and have a high potential for abuse.

4. The research on the effectiveness of Lorcaserin also showed that half of the study participants taking the placebo also maintained weight loss for a two year period. (True/ False)

5. Orlistat increases the absorption of vitamins A, D, E, and K. (True/ False)

6. People on a very low calorie diet (600-800 kcal/day) are three times more likely to develop gallstones than someone following a low calorie diet. (True/ False)

7. The research on meal replacements show that the weight loss effects are comparable to weight loss with drugs, such as orlistat and lorcaserin. (True/ False)

8. Exercising while fasting is recommended as a way to expedite weight loss. (True/ False)

9. In cases of prolonged fasting, decreasing the metabolic rate may make regaining weight easier. (True/ False)

10. The scientific literature demonstrates some short-term success with participants in a modified fast program. (True/ False)

11. Most commercial weight loss programs are technically “medically supervised.”

(True/ False)

12. Approximately 70% of people who begin commercial low calorie diets dropout within twelve weeks. (True/ False)

13. Being able to identify a person’s genotype might allow us to someday suggest a specific diet (e.g. low carb, low fat, balanced diet) and improve weight loss success. (True/ False)

14. Half of adult women and one quarter of adult men will go on a diet this year. (True/ False).

15. Vitamins and minerals are the only dietary supplements. (True/ False)

16. According to FDA analysis, many of the dietary supplements vary widely and many products marketed as “natural” or “herbal” contain harmful ingredients. (True/ False)

17. Dietary supplements are the same as drugs. (True/ False)

18. There is ample evidence that chitosan promotes weight loss in humans. (True/ False)

19. In theory, excess pyruvate might accelerate aerobic metabolism, oxidizing blood glucose and prevent conversion of excess carbohydrate to fat. (True/ False)

20. Dieter’s teas promote weight loss by speeding food through the digestive tract so calories cannot be absorbed. (True/ False)

21. “Fat burning” herbal supplements have been implicated in documented cases of liver toxicity. (True/ False)

22. Individuals who binge and demonstrate an inability to make dietary or activity modifications are usually good candidates for bariatric surgery. (True/ False)

23. Laparoscopic adjustable gastric banding does not result in as much weight loss as gastric bypass surgery but has fewer complications. (True/ False)

24. Cellulite is easy to treat because it involves weak connective tissue as well as clumped fat cells. (True/ False)

25. Fat deposits generally do not return after liposuction. (True/ False)

26. Cellulite occurs in both lean and obese women. (True/ False)

27. With the exception of gastric surgery, the more extreme weight control approaches result in about the same amount of weight loss as behavioral programs. (True/ False)

Multiple Choice

28. ____________________ are drugs that suppress appetite and reduce food intake.

    A. Catecholaminergic drugs

    B. Anorectic, or Anorexiant drugs

    C. Serotonergic drugs

    D. All of the above

29. Lorcaserin is a weight loss drug that reduces food intake by acting on the serotonin receptor in the ____________________.

    A. Hypothalamus

    B. Limbic System

    C. Prefrontal Cortex

    D. All of the above

30. _____________________ is a drug that blocks the absorption of about 30% of dietary fat from the small intestine.

    A. Olestra

    B. Orlistat

    C. Phentermine/Topiramate

    D. All of the above

31. _____________________ are deposits made of cholesterol, bile, and calcium salts that form in the gallbladder and may block the duct between the gallbladder and the duodenum, causing pain.

    A. Gout

    B. Gallstones

    C. Necrotic fasciitis

    D. All of the above

32. ____________________ involves the deposition of excess uric acid in the joints, especially the big toe, causing swelling and pain.

    A. Gout

    B. Gallstones

    C. Necrotic fasciitis

    D. Arthritis

33. Very low calorie diets are classified as containing no more than _______ kcal per day.

    A. 600 kcal

    B. 800 kcal

    C. 1,200 kcal

34. _______ to _______mg of caffeine per day is not harmful to most adults (this is the equivalent to about three cups of coffee).

    A. 100-300 mg

    B. 200-400 mg

    C. 300-500 mg

    D. 400-600 mg

35. More than ______ mg of caffeine a day has been associated with extreme anxiety, heart palpitations, paranoia and even death.

    A. 200 mg

    B. 300 mg

    C. 400 mg

    D. 500 mg

36. ____________________ is a mineral needed in small amounts for normal carbohydrate and lipid metabolism as well as insulin function.

    A. Caffeine

    B. Chromium

    C. Calcium

    D. Magnesium

37. Bariatric surgery is usually restricted to people whose BMI is ______ or higher.

    A. 28

    B.30

    C. 35

    D. 40

38. ___________________ is the most common type of liposuction procedure in use today.

    A. Tumescent liposuction

    B. Ultrasound assisted liposuction

    C. Laser assisted liposuction

    D. All of the above

39. This type of liposuction has the highest complication rate.

    A. Tumescent liposuction

    B. Ultrasound assisted liposuction

    C. Laser Assisted liposuction

    D. All of the above.

40. A ____________________ occurs when a piece of fat tissue lodges in an artery.

    A. pulmonary embolism

    B. fat embolism

    C. hypertension

    D. all of the above

41. “USP” on a dietary supplement container signifies that

    A.  the manufacturer has followed U.S. Pharmacopeia standards for quality

    B.  the product should be used as prescribed

    C.  the product contains untested ingredients

    D.  the product is understood to be safe

42. Which of the following statements about ephedra/caffeine supplements is FALSE?

A.  these supplements have cause hundreds of adverse reaction complaints at   

     the FDA

    B.  some evidence supports the use of these supplements in weight loss

    C. ephedra bears no resemblance to prescription ephedrine

    D.  this supplement combination functions as a stimulant

Short Answer/ Fill in the Blank

43.  ______________________ are also known as “uppers.” This is a classification of drugs that stimulate the central nervous system and have high potential for abuse.

44. ____________________ is the federal agency responsible for overseeing the safety of food, drugs, nutritional supplements, cosmetics, and medical devices.

45. Describe the characteristics of a good weight loss drug. What are some realistic expectations from weight loss drugs?

46. What are three of the factors that are considered by the FDA prior to approving a new weight loss drug?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

3)______________________________________________________________________________________________

47. What are the two broad categories of anti-obesity drugs?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

48. What are two of the additional health benefits of orlistat?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

49. What are some of the negative side effects of orlistat?

50.  Overall, what are some of the negative side effects of weight loss drugs?

51.  What are three of the physiological effects of caloric restriction (very low calorie diets)?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

3)______________________________________________________________________________________________

52. What are the characteristics of a very low calorie diet (VLCD)?  What are the short-term and long-term weight loss and health outcomes of a VLCD?

53. Provide two of the reasons that meal replacements work well for short term weight loss:

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

54. Describe the characteristics of a low carb diet. What are the effects of a low-carb/ high fat diet on health?

55. How do the very low fat diets (e.g. Pritikin diet and Ornish program) compare to low carb diets?

56. What are the three questions an individual should ask prior to beginning a medically unsupervised low calorie diet?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

3)______________________________________________________________________________________________

57. A ___________________ is a product (other than tobacco) that contains a vitamin, mineral, amino acid, herb or other botanical, any extract or combination of these; they are intended for ingestion in a pill, capsule, tablet, or liquid form and are not considered to be conventional foods or the sole item consumed in a meal.

58. How are dietary supplements regulated by the FDA?

59. How are dietary supplements different from drugs?

60. What are two dietary supplements that claim to promote weight loss?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

61. What are some of the problems with the dietary supplements that are advertised to promote weight loss? What are some of the signs that a product may not be all that it is claimed to be?

62. What are two of the recommendations for identifying quality dietary supplements?

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

63. Surgical procedures for the treatment of obesity are called ____________________.

64. What is one of the most common bariatric surgical procedures?

65. ____________________ involves the insertion of a small scope through the abdominal wall to examine the abdominal cavity or perform surgery.

66. What are the benefits of bariatric surgery?  What are some of the additional factors that impact successful outcomes?

67. ____________________ is adipose tissue characterized by a dimpled appearance due to weak connective tissue that allows fat to penetrate into the dermis.

68. Name two nonsurgical treatments for cellulite:

1)______________________________________________________________________________________________

2)______________________________________________________________________________________________

69. What are some of the adverse effects of liposuction?

70. An overweight client/patient is considering drugs, gastric surgery, or a very-low-calorie diet for weight loss.  List at least two advantages and two disadvantages of each form of treatment.  

71. What are two important points that you would raise with someone who wanted to take a dietary supplement for weight loss.