Words into action—promoting successful weight loss in overweight patients

Jump to:

Choose article section...Learning objectives Disclosure of conflict of interest Evaluation of obesity and associated risks Weight-loss diets The hazards of dieting Beyond the diet: The role of exercise and drugs Alternative treatments for weight control Diet drugs of the future KEY POINTS in this article

Silvia E. Hines

Ms. Hines is a freelance medical writer. The author has indicated no relationships to disclose relating to the content of this article.

A patient who wants to lose weight is faced with a daunting array of weight-loss options and conflicting claims. Here's how to sort them all out.

Reducing the incidence of obesity has become a major objective of various government agencies, including the Office of the Surgeon General¹ and the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH).^2,3 It is the clinician, however, who must inform overweight and obese patients of the health risks of their excess weight and urge them to take steps to reduce it. Providers may need to overcome a reluctance to discuss weight with patients that is rooted in time constraints, lack of reimbursement, the social stigma of obesity, or the perception that patients will not follow their advice. Clinicians may share the societal view that obesity results from a lack of discipline rather than from an underlying chronic disease process. PAs will find it helpful to keep conversations focused on health outcomes and to support patients' self-esteem by stressing responsibility without blame.

Once patients are convinced of the importance of losing weight, they need not be left to their own devices to figure out the best way to accomplish the task. You can help patients wade through the abundance of information about diets and diet products available today. Urging patients to choose a healthier lifestyle is the first step in the weight-loss effort. Even small dietary changes and increases in physical activity can have health benefits. Since social and behavioral factors are involved in the persistence of overweight and obesity, psychological interventions, such as behavior modification or membership in a weight-loss group, should be considered, where appropriate, in addition to diet (see "The behavior and psychology of weight management"). A three-pronged approach consisting of dietary change, increased physical activity, and behavior modification is often more effective than diet, or diet and exercise, alone.

PAs, in the forefront of preventive medicine, are in a key position for encouraging and helping patients to lose weight. This article describes trial results and evidence-based guidelines in order to equip PAs for the task of assisting overweight and obese patients to achieve and maintain weight loss.

Evaluation of obesity and associated risks

Early steps in obesity management include assessing patients' related health risks and ruling out obesity secondary to other, treatable disorders, such as hypothyroidism and to the use of some drugs, such as corticosteroids. The extent of obesity may then be determined through weight and height measurements and by calculation of the body mass index (BMI), a measure that is correlated with total body fat content. BMI is equal to weight in kilograms divided by the square of height in meters. BMI may also be calculated in pounds and inches by dividing weight in pounds by the square of height in inches and multiplying the result by 703.

Standards defining overweight and obesity on the basis of BMI were developed by the International Obesity Task Force of the World Health Organization⁴ and adopted by an expert committee of the NHLBI.² A patient whose BMI is between 25.0 and 29.9 kg/m² is considered overweight, and one whose BMI is 30.0 kg/m² or higher is considered obese. Obesity is further categorized as class I (BMI 30.0 to 34.9 kg/m²), class II (BMI 35.0 to 35.9 kg/m²), or class III (BMI 40 kg/m² and greater).

Waist circumference should be measured as well, because of the association of abdominal fat, or central obesity, with metabolic disorders and hypertension.⁵ Waist circumference is reported to be a more accurate reflector of central obesity than either BMI or waist-hip ratio.⁶ A waist circumference greater than 35 inches in women or 40 inches in men is associated with increased risk. The NHLBI guidelines for treatment of overweight and obesity currently recommend treating patients with a BMI of 30 kg/m² or higher regardless of health risk factors, but treating patients with a BMI between 25.0 and 29.9 kg/m² or a large waist circumference only if they have two or more risk factors.² Risk factors include hypertension, cigarette smoking, dyslipidemia, impaired fasting glucose, and a family history of coronary heart disease.

A conversation with the patient should help to determine readiness to change lifestyle and habits. Issues to discuss include weight history, previous weight-loss attempts, reasons for wanting to lose weight, barriers to weight loss, and social supports.⁷ The presence of a major life stressor or an eating disorder may necessitate referral to a specialist before weight loss is addressed. After this assessment, engage in goal setting with the patient. NHLBI guidelines suggest setting an initial goal of a 5% to 10% reduction in body weight during the first 6 months and aiming for a rate of weight loss of about 1 to 2 pounds per week.³ To achieve these goals, patients need to know their daily caloric requirement for maintaining their present weight as well as for losing weight. Approximate average daily energy needs for men, women, and children are shown in Table 1.

TABLE 1 Recommended average daily energy allowances for children and adults*
Age, y	Kcal/kg	Kcal/d
CHILDREN
1-3	102	1,300
4-6	90	1,800
7-10	70	2,000
MEN
11-14	55	2,500
15-18	45	3,000
19-24	40	2,900
25-50	37	2,900
>50	30	2,300
WOMEN†
11-14	47	2,200
15-18	40	2,200
19-24	38	2,200
25-50	36	2,200
>50	30	1,900
*Engaged in light to moderate physical activity, with no underlying medical condition. †Nonpregnant, nonlactating.
Adapted from National Research Council. Recommended Dietary Allowances. Subcommittee on the Tenth Edition of the RDAs, Food Nutrition Board, Commission on Life Sciences. 10th ed. Washington, DC: National Academy Pr; 1989:32.

Weight-loss diets

To achieve and maintain weight loss, patients must restrict energy intake and increase energy expenditure. While increasing expenditure is a relatively straightforward task, restricting intake can be accomplished in a number of ways, some safer and more effective than others. The limited success of dieting alone beyond the short term⁸ and the reported poor methodologic quality of weight-loss studies make it difficult for the clinician to confidently recommend specific diets.⁹

In designing or recommending a diet, remember that the etiology of obesity is complex, with genetic, metabolic, biochemical, cultural, and psychosocial contributions.¹⁰ A particular challenge is helping patients overcome the cultural factors that promote the maintenance of obesity, such as the ready availability of palatable, energy-dense prepared foods, often served in overly large portions. Patients must learn to replace these prepared foods and "fast foods" with less energy-dense foods, eaten in smaller portions. Consideration should be given both to the relative proportions of carbohydrate, fat, and protein that best promote weight loss and to the types of foods in each category that best promote health.

The optimal proportions are controversial, with proponents of low-fat, low-carbohydrate, and high-protein diets sparring for the spotlight. The best types of carbohydrate, fat, and protein are less controversial. Carbohydrates should be complex—those found in vegetables, fruits, and whole grains—rather than simple*those found in refined sugars and flours. Five or more servings per day of vegetables and fruits are typically recommended.⁵ Protein-rich foods should be lean to avoid excessive intake of saturated fat. Fats should be used sparingly, but intake of omega-3 fatty acids from fish and fish oils should be promoted.^11,12 Olive and canola oils may be used, but consumption of hydrogenated or partially hydrogenated oils (trans-fatty acids) should be minimized.¹³

Some data suggest that eating breakfast may be a factor in successful weight loss. Among the participants in the National Weight Control Registry who maintained a loss of at least 30 pounds for at least 1 year, 78% reported eating breakfast every day, while only 4% reported never eating breakfast.¹⁴ There was no difference in reported energy intake between breakfast eaters and noneaters, although breakfast eaters reported slightly more physical activity.

Low-fat diets Excessive intake of fat has long been considered the principal cause of adiposity. The recommendation that dieters reduce the amount of fat that they consume is based on the consistent association of dietary fat with body fat, probably owing to the energy density of fat.¹⁵ Patients may be well aware of this fact: A telephone survey revealed that a common strategy among respondents was to attempt weight loss through reduction of dietary fat alone, without concomitant calorie restriction or exercise.¹⁶

A low-fat diet contains about 10% to 19% of calories in fat, whereas a very-low-fat diet, as advocated by proponent Dean Ornish, contains less than 10% of calories in fat. Although dietary intervention trials clearly show that low-fat diets promote weight loss in both overweight and normal weight people in the short term, the relative benefit of these diets over the long term is uncertain. In a review of six randomized controlled trials with follow-up for 6 to 18 months, investigators found no significant differences in sustained weight loss between groups following low-fat diets and those following other types of weight-reducing diets.¹⁷ One problem with low-fat diets from a health standpoint is that they may turn out to be high in refined carbohydrates, although their proponents do not intend this consequence.¹⁸

Low-carbohydrate diets This approach has been touted for more than 100 years, since William Banting reported a loss of 46 pounds on a low-carbohydrate regimen.¹⁹ Usually defined as containing less than 60 to 100 grams of carbohydrate daily, low-carbohydrate diets are likely to be high in protein. Proponents point to a sharp rise in the intake of sugar and refined carbohydrates in the United States in the past 30 years as a cause of increased obesity. In contrast to critics' concerns regarding the risks associated with increased fat intake, Robert Atkins, the most visible proponent of the low-carbohydrate diet, held that when carbohydrate intake is low, fat takes a different metabolic pathway, forming energy through ketones, which are quickly burned, rather than accumulating.¹⁸

Until recently, there has been a lack of compelling evidence of a link between carbohydrate intake and risk of obesity or of an association between carbohydrate-restricted diets and sustainable weight loss. In one study, weight loss was greater on a high-protein, low-carbohydrate diet compared to a high-carbohydrate diet (8.9 kg vs 5.1 kg).²⁰ However, in a recent comparison of a low-carbohydrate diet with a conventional low-fat diet, participants in the low-carbohydrate group lost more weight in the first 6 months, but the difference did not remain significant after 1 year.²¹ Notably, the low-carbohydrate group had greater improvements in HDL cholesterol and triglyceride concentrations, a result that might be expected on the basis of Atkins's ketone theory; alternatively, fat intake may not be increased significantly on a low-carbohydrate diet.²²

The effectiveness of low-carbohydrate diets may not result directly from the carbohydrate content. According to a recent review of published studies of low-carbohydrate diets, weight loss was associated with restricted calorie intake and longer diet duration rather than reduced carbohydrate content.¹⁹ The reviewers concluded there was insufficient evidence on which to base a recommendation for or against low-carbohydrate diets and that additional follow-up study was needed.

Low-calorie diets It appears that reduced calorie intake results in weight loss regardless of the macronutrient content.²³ Both low-fat and low-carbohydrate diets can succeed, therefore, because they significantly reduce calories, since fats and carbohydrates are both energy-dense constituents of food. It is possible, however, for a patient to consume a diet that is sufficiently low in calories to effect weight loss but is lacking in essential nutritional elements. Patients should be warned that such diets can be harmful to their health. In addition, patients should be cautioned against attempting a very-low-calorie diet (VLCD) without medical supervision. Moreover, there is evidence that the benefits of VLCDs, which may be featured in commercial diet programs, are limited to the short term.⁸

The American College of Preventive Medicine recommends that overweight and obese patients receive counseling concerning an energy-reduced, or low-calorie, diet consisting of 800 to 1,500 kcal/d.⁸ The NHLBI guidelines advocate a diet that creates a deficit of 500 to 1,000 kcal/d to achieve a weight loss of 1 to 2 lb per week.² This deficit may require subtracting 500 to 1,000 kcal/d from patients' estimated caloric requirements (see Table 1).

Commercial diets Studies of the effectiveness of liquid formula diets and diets outlined in books tend to be invalid because the participants are usually self-selected rather than randomly assigned.⁸ Few studies have been done comparing the long-term effects of commercial weight-loss programs with the results of other methods of dieting. In a study of the Sandoz Nutrition diet program, 40% of participants later regained more weight than they had initially lost, and only 12% maintained 75% of their weight loss after completing the program.²⁴

The hazards of dieting

Although the health risks of obesity are well established, the hazards of dieting may also be formidable. Patients should be cautioned concerning the potential detrimental effects of VLCDs, defined as diets containing fewer than 800 kcal/d, when undertaken without medical supervision. VLCDs have been associated with arrhythmias, gout, gallstones, hair loss, cold intolerance, diarrhea, and fatigue.⁸ Weight cycling, resulting from repeated dieting and regaining of weight, appears to present risks as well. Retrospective studies have linked weight cycling with cardiovascular events and increased mortality, although the findings were not corroborated in a meta-analysis.⁸

Despite these potential risks, most authorities believe that the evidence linking obesity with chronic disease and mortality is sufficient to justify medically supervised dietary treatment. Many studies have shown reductions in risk of obesity-related conditions over the short term after intentional weight loss.²⁵ Practitioners should monitor patients to avoid excessive loss of lean body tissue, electrolyte imbalance, dehydration, gallbladder disease, and psychological distress. Patients following VLCDs should have essential amino acids and micronutrients replenished.⁸

Beyond the diet: The role of exercise and drugs

Although dietary modification can result in weight loss, most people cannot maintain their losses on that basis alone.²⁵ Exercise is a necessary adjunct; pharmacotherapy is justifiable in specific circumstances; and alternative treatments, such as nutritional supplements, acupuncture, and hypnosis, may be worth trying for interested patients (see "Alternative treatments for weight control").

 

Alternative treatments for weight control Because of the refractory nature of obesity, patients often become interested in alternative approaches to controlling weight. One researcher concluded that alternative therapies for weight control were generally not rigorously tested but that some had plausible mechanisms of action and encouraging preliminary data.1 Patients should be reminded that diet modification and exercise must not be abandoned when other types of therapy are attempted. Nutritional supplements The efficacy and adverse effects of nutritional supplements used for weight loss are generally unknown. While some approaches are likely harmless, such as the short-term use of trace minerals, others may have serious side effects. Clinicians can encourage patients to bring in any supplement they are taking so the label can be checked. Chromium picolinate is a trace mineral supplement that enhances insulin activity, increases lean body mass, and raises basal metabolic rate; these effects led to its promotion for use in weight reduction. A meta-analysis of randomized controlled trials demonstrated a small effect on weight reduction for this product compared with placebo.2 Two Chinese herbal products used for weight reduction have presented problems in the past decade. The adverse effects of ephedra are mentioned in the discussion of ephedrine (see "OTC drugs"). Cases of "Chinese herb nephropathy," reported in the early 1990s, were caused by a manufacturing error; one of the herbs in a combination diet product was inadvertently replaced by another, Aristolochia fangchi, which is nephrotoxic and carcinogenic.3 Acupuncture Stimulation of acupuncture points is said to correct an imbalance of chi, a vital energy postulated in Eastern medical systems, sometimes translated as "life force." Western medicine's interpretation of the effects of acupuncture suggests that CNS neurotransmitter levels are altered through the stimulation of peripheral nerves.4 The literature concerning acupuncture for obesity treatment tends to be marred by studies that are often only descriptive in nature and of short duration (12 weeks or less) and by the difficulty of instituting an adequate placebo control for the procedure. A recent review of studies concluded only that additional careful study was in order.4 1. Allison DB, Fontaine KR, Heshka S, et al. Alternative treatments for weight loss: a critical review. Crit Rev Food Sci Nutr. 2001;41:1-28. 2. Pittler MH, Stevinson C, Ernst E. Chromium picolinate for reducing body weight: meta-analysis of randomized trials. Int J Obes Relat Metab Disord. 2003;27:522-529. 3. Nortier JL, Martinez MC, Schmeiser HH, et al. Urothelial carcinoma associated with the use of a Chinese herb (Aristolochia fangchi). N Engl J Med. 2000;342:1686-1692. 4. Lacey JM, Tershakovec AM, Foster GD. Acupuncture for the treatment of obesity: a review of the evidence. Int J Obes Relat Metab Disord. 2003;27:419-427.

Exercise is essential If maintenance of desirable weight depends on the balance between energy intake and energy expenditure, it is evident that physical activity occupies 50% of the equation. At one time, vigorous exercise was thought to increase the appetite so much that any benefit would be counteracted by additional eating. That theory has long been laid to rest, and physical activity is universally considered an important component of any weight-loss or weight-maintenance regimen.

Throughout most of human history, physical activity was required for survival. Modern technology has almost eliminated that requirement for performing necessary tasks both at home and at work. Leisure time, too, is often spent in sedentary activities, such as watching television or surfing the Internet. Obese patients may be particularly adept at avoiding opportunities for physical activity owing to difficulty with mobility or discouragement.

According to a meta-analysis of weight-loss studies, the likelihood of achieving long-term maintenance of weight loss is significantly enhanced when exercise is combined with diet.²⁶ Regular exercise alone, on the other hand, leads to modest weight loss, usually less than what is reported when calorie restriction is part of the program.²⁷ In addition, increased physical activity, as well as the increased muscle mass that may result, is believed to at least partially compensate for the decreased basal metabolic rate that often accompanies weight loss; this adjustment may protect against weight regain.²⁸ Finally, regular physical activity is likely to be beneficial to health, reducing the risk of diabetes and coronary heart disease beyond what may be attributed to weight loss alone.²⁹

The NHLBI guidelines recommend starting with 30 to 40 minutes of exercise per day 3 to 5 days a week and setting a long-term goal of 30 minutes or more a day on most, preferably all, days.² The exact amount of exercise may not be important: In a recent year-long trial comparing the effects of different exercise regimens along with a low-calorie diet, weight loss and improved cardiorespiratory fitness were achieved, but neither was related to either intensity or duration of the exercise regimen.³⁰

Patients may need to introduce exercise into their lives slowly. In addition to following a daily exercise regimen, they can be encouraged to incorporate incidental and leisure time activities into their daily routine—for example, taking stairs instead of the elevator and walking rather than driving, whenever possible. Planned activities can include walking, fitness classes, and swimming. Strength training may be desirable to help certain patients achieve overall fitness. Those who want to institute a daily walking routine may find it feasible to start walking for only 10 minutes 3 days a week and build up gradually to 30 to 45 minutes or more of brisk walking 5 to 7 days a week.

Pharmacotherapy is optional Guidelines for use of pharmacotherapy call for caution in prescribing. The American College of Preventive Medicine reported that evidence is lacking to support either short- or long-term use of drugs for weight loss and suggested that such therapy be individualized in accordance with clinical judgment.⁸ The NHLBI guidelines reserve pharmacotherapy for patients who have a BMI higher than 27 kg/m² along with obesity-related disorders such as hypertension, dyslipidemia, coronary heart disease, or type 2 diabetes, or for patients whose BMI is higher than 30 kg/m² regardless of comorbid conditions.² Pharmacotherapy clearly should not be undertaken without concomitant lifestyle modification, and drug efficacy and safety should be continually assessed.

The literature regarding weight-loss drugs must be examined with caution. In some cases, appetite-suppressant drugs have shown short-term efficacy in trials funded by the pharmaceutical industry, but weight is generally regained after discontinuation and long-term safety is unknown.⁸ In a well-publicized case, a combination weight-loss drug containing fenfluramine or dexfenfluramine plus phentermine*popularly known as "fen-phen"*was withdrawn from the market in 1997 because of its association with valvular injuries.³¹

Prescription drugs Presently, two drugs are FDA approved for long-term use in the management of obesity: sibutramine (Meridia), which acts by reducing cravings and increasing satiety, and orlistat (Xenical), an inhibitor of intestinal lipid peroxidase. Phentermine is still approved for short-term use, and several other drugs are under investigation (see "Diet drugs of the future").

 

Diet drugs of the future Weight-loss drugs of the future will doubtless be developed out of increased understanding of the etiology and pathophysiology of obesity. In two cases, however, drugs that are nearing the approval stage were discovered incidentally—when weight loss was found to be a side effect of their use in other diseases. Zonisamide (Zonegran) is an anticonvulsant drug that was associated with weight loss as an adverse effect in clinical trials in patients with epilepsy. In a preliminary, short-term trial of its efficacy as an anti-obesity drug, zonisamide, along with a calorie-reduced diet, resulted in greater weight loss than did placebo with the same diet.1 Ciliary neurotrophic factor (CNTF) is a neuroprotective substance found to induce weight loss when tested in patients with amyotrophic lateral sclerosis (ALS). Investigators discovered subsequently that CNTF activated signaling pathways in neurons of an appetite-control center in the hypothalamus; this mechanism is related to the function of the weight-regulating hormone leptin.2 A recombinant form of CNTF (rhvCNTF) was shown to bypass the resistance typically shown to exogenously administered leptin. In a short-term dose-ranging study, obese patients treated with rhvCNTF lost more weight than those treated with placebo.2 This drug has been moved to "fast track" status by the FDA.3 Researchers are looking at the potential of amylin, a recently discovered naturally occurring hormone released by the beta cells of the pancreas, for the treatment of obesity. Also called islet amyloid polypeptide, amylin has been found to be elevated in obese people. It has been suggested that these elevated levels may lead to down-regulation of amylin receptors and reduce the impact of postprandial amylin secretion on satiety and gastric emptying. Administration of amylin may decrease food intake as well as slow gastric emptying.4 1. Gadde KM, Franciscy DM, Wagner HR II, Krishnan KR. Zonisamide for weight loss in obese adults: a randomized controlled trial. JAMA. 2003;289:1820-1825. 2. Ettinger MP, Littlejohn TW, Schwartz SL, et al. Recombinant variant of ciliary neurotrophic factor for weight loss in obese adults: a randomized, dose-ranging study. JAMA. 2003;289:1826-1832. 3. Vastag B. Experimental drugs take aim at obesity. JAMA. 2003;289:1763-1764. 4. Reda TK, Geliebter A, Pi-Sunyer FX. Amylin, food intake, and obesity. Obes Res. 2002;10:1087-1091.

In a 2-year randomized controlled trial of orlistat, a group receiving the drug along with dietary modification lost more weight and maintained the loss somewhat more successfully than a placebo group.³² In an 18-week trial of orlistat plus a diet mildly reduced in calories, significantly more patients taking orlistat lost 10% or more of their initial body weight compared to those taking placebo.³³ Those taking orlistat also were more likely to maintain their weight loss and had a greater decrease in fasting blood glucose and LDL cholesterol levels compared to control patients. Adverse effects of orlistat include inhibition of water and vitamin absorption in some patients, resulting in cramping and diarrhea, as well as rebound weight gain.³⁴

Sibutramine also attenuates the drop in metabolic rate associated with significant weight loss. Clinical trials showed that two thirds of patients taking sibutramine lost at least 5% of their weight.³⁵ Dose-related weight loss with sibutramine has been accompanied by improved serum lipid and uric acid levels but also by small mean increases in heart rate and BP (approximately 4 mm Hg).³⁶ Clinicians should therefore take care to follow recommended exclusion criteria, monitor BP and heart rate, and observe withdrawal criteria.³⁷ Like orlistat, sibutramine may cause rebound weight gain.³⁴

The concurrence of obesity and depressive symptoms, particularly among patients seeking treatment for depression, has led to investigation of the effects of the antidepressant bupropion on weight loss. In a randomized controlled trial involving obese patients with depressive symptoms but not major depression, significantly more patients treated with bupropion than placebo, along with a 500-kcal/d deficit, lost at least 5% of their baseline weight.³⁸ Improvement in depressive symptoms was, however, strongly related to loss of at least 5% of body weight regardless of treatment.

OTC drugs Patients should be cautioned concerning the uncertain or hazardous effects of OTC diet drugs. Phenylpropanolamine (PPA) is a sympathetic amine found in cold remedies and in weight-control products such as Dexatrim. Use of this appetite suppressant has been associated with hypertensive episodes and hemorrhagic stroke, particularly in younger women.³⁹ In addition, abuse and overuse of PPA have been linked with myocardial injury in seven cases; in one case report, myocardial injury in a young woman followed the use of Dexatrim at doses recommended for weight control.³⁹

Ephedrine, a synthetic drug derived from the Chinese herb Ephedra sinica, is a decongestant and bronchodilator also found in weight-loss products. In a meta-analysis of studies of ephedrine or ephedra, researchers found evidence of modest short-term weight loss.⁴⁰ However, use of either substance combined with caffeine was linked with increased risk of psychiatric, autonomic, and GI symptoms as well as with heart palpitations.⁴⁰ In February, the FDA prohibited the sale of dietary supplements containing ephedra because they present an unreasonable risk of illness or injury.⁴¹

 

KEY POINTS in this article A three-pronged approach consisting of dietary change, increased physical activity, and behavior modification is often more effective at achieving and maintaining weight loss than is diet, or diet and exercise, alone. Exercise is critical to both losing weight and maintaining a healthy weight. Drugs may help some patients. Caution patients against attempting a very-low-calorie diet without medical supervision. Besides the health concerns, these diets appear to have only short-term benefits.

REFERENCES

1. Office of the Surgeon General, US Department of Health and Human Services. The Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity. 2001. Available at: http://www.surgeongeneral.gov/topics/obesity/calltoaction/toc.htm . Accessed March 4, 2004.

2. The National Heart, Lung, and Blood Institute and National Institute of Diabetes and Digestive and Kidney Diseases. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults. 1998. Available at: http://www.nhlbi.nih.gov/guidelines/obesity/ob_home.htm . Accessed March 4, 2004.

3. The National Heart, Lung, and Blood Institute and North American Association for the Study of Obesity. The Practical Guide: Identification, evaluation, and treatment of overweight and obesity in adults. Available at: http://www.nhlbi.gov/guidelines/obesity/practgde.htm . Accessed March 4, 2004.

4. World Health Organization. Obesity: preventing and managing the global epidemic. Report of the World Health Organization on Obesity. Geneva, Switzerland; 1998. Available at: http://www.who.int/nut/documents/obesity_executive_summary.pdf . Accessed October 16, 2003.

5. McInnis KJ. Diet, exercise, and the challenge of combating obesity in primary care. J Cardiovasc Nurs. 2003;18:93-100.

6. Sönmez K, Akçakoyun M, Akçay A, et al. Which method should be used to determine the obesity, in patients with coronary artery disease? (body mass index, waist circumference or waist-hip ratio) Int J Obes Relat Metab Disord. 2003;27:341-346.

7. Serdula MK, Khan LK, Dietz WH. Weight loss counseling revisited. JAMA. 2003;289:1747-1750.

8. Nawaz H, Katz DL. American College of Preventive Medicine practice policy statement. Weight management counseling of overweight adults. Am J Prev Med. 2001;21:73-78.

9. Glenny A-M, O'Meara S, Melville A, et al. The treatment and prevention of obesity: a systematic review of the literature. Int J Obes Relat Metab Disord. 1997;21:715-737.

10. Lyznicki JM, Young DC, Riggs JA, et al. Obesity: assessment and management in primary care. Am Fam Physician. 2001; 63:2185-2196.

11. Mori TA, Bao DQ, Burke V, et al. Dietary fish as a major component of a weight-loss diet: effect on the serum lipids, glucose, and insulin metabolism in overweight hypertensive subjects. Am J Clin Nutr. 1999;70:817-825.

12. Méndez-Sánchez N, González V, Aguayo P, et al. Fish oil (n-3) polyunsaturated fatty acids beneficially affect biliary cholesterol nucleation time in obese women losing weight. J Nutr. 2001;131:2300-2303.

13. Baylin A, Kabagambe EK, Ascherio A, et al. High 18:2 trans-fatty acids in adipose tissue are associated with increased risk of nonfatal acute myocardial infarction in costa rican adults. J Nutr. 2003;133:1186-1191.

14. Wyatt HR, Grunwald GK, Mosca CL, et al. Long-term weight loss and breakfast in subjects in the National Weight Control Registry. Obes Res. 2002;10:78-82.

15. Bray GA, Popkin BM. Dietary fat intake does affect obesity! Am J Clin Nutr. 1998;68:1157-1173.

16. Serdula MK, Mokdad AH, Williamson DF, et al. Prevalence of attempting weight loss and strategies for controlling weight. JAMA. 1999;282:1353-1358.

17. Pirozzo S, Summerbell C, Cameron C, Glasziou P. Should we recommend low-fat diets for obesity? Obes Rev. 2003;4(2):83-90.

18. Stephenson J. Low-carb, low-fat diet gurus face off. JAMA. 2003;289:1767-1773.

19. Bravata DM, Sanders L, Huang J, et al. Efficacy and safety of low-carbohydrate diets. A systematic review. JAMA. 2003; 289:1837-1850.

20. Skov AR, Toubro S, Ronn B, et al. Randomized trial on protein vs carbohydrate in ad libitum fat reduced diet for the treatment of obesity. Int J Obes Relat Metab Disord. May 1999;23:528-536.

21. Foster GD, Wyatt HR, Hill JO, et al. A randomized trial of a low-carbohydrate diet for obesity. N Engl J Med. 2003;348:2082-2090.

22. Bray GA. Low-carbohydrate diets and realities of weight loss [editorial]. JAMA. 2003;289:1853-1855.

23. Freedman MR, King J, Kennedy E. Popular diets: a scientific review. Obes Res. 2001;9(suppl 1):1S-40S.

24. Grodstein F, Levine R, Troy L, et al. Three-year follow-up of participants in a commercial weight loss program. Can you keep it off? Arch Intern Med. 1996;156:1302-1306.

25. National Task Force on the Prevention and Treatment of Obesity. Overweight, obesity, and health risk. Arch Intern Med. 2000;160:898-904.

26. Miller WC, Koceja DM, Hamilton EJ. A meta-analysis of the past 25 years of weight loss research using diet, exercise or diet plus exercise intervention. Int J Obes Relat Metab Disord. 1997;21:941-947.

27. Skender ML, Goodrick GK, Del Junco DJ, et al. Comparison of 2-year weight loss trends in behavioral treatments of obesity: diet, exercise, and combination interventions. J Am Diet Assoc. 1996;96:342-346.

28. Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995;332:621-628.

29. Hill JO, Wyatt H. Outpatient management of obesity: a primary care perspective. Obes Res. 2002;10(suppl 2):124S-130S.

30. Jakicic JM, Marcus BH, Gallagher KI, et al. Effect of exercise duration and intensity on weight loss in overweight, sedentary women: a randomized trial. JAMA. 2003;290:1323-1330.

31. Weissman NJ, Tighe JF Jr, Gottdiener JS, Gwynne JT, for the Sustained-Release Dexfenfluramine Study Group. An assessment of heart-valve abnormalities in obese patients taking dexfenfluramine, sustained-release dexfenfluramine, or placebo. N Engl J Med. 1998;339:725-732.

32. Davidson MH, Hauptman J, DiGirolamo M, et al. Weight control and risk factor reduction in obese subjects treated for 2 years with orlistat: a randomized controlled trial. JAMA. 1999;281:235-242.

33. Krempf M, Louvet J-P, Allanic H, et al. Weight reduction and long-term maintenance after 18 months treatment with orlistat for obesity. Int J Obes Relat Metab Disord. 2003;27:591-597.

34. Vastag B. Experimental drugs take aim at obesity. JAMA. 2003;289:1763-1764.

35. Finer N. Sibutramine: its mode of action and efficacy. Int J Obes Relat Metab Disord. 2002;26(suppl 4):S29-S33.

36. Bray GA, Blackburn GL, Ferguson JM, et al. Sibutramine produces dose-related weight loss. Obes Res. 1999;7:189-198.

37. Narkiewicz K. Sibutramine and its cardiovascular profile. Int J Obes Relat Metab Disord. 2002;26(suppl 4):S38-S41.

38. Jain AK, Kaplan RA, Gadde KM, et al. Bupropion SR vs. placebo for weight loss in obese patients with depressive symptoms. Obes Res. 2002;10:1049-1056.

39. Pilsczek FH, Karcic AA, Freeman I. Case report: Dexatrim (phenylpropanolamine) as a cause of myocardial infarction. Heart Lung. 2003;32:100-104.

40. Shekelle PG, Hardy ML, Morton SC, et al. Efficacy and safety of ephedra and ephedrine for weight loss and athletic performance: a meta-analysis. JAMA. 2003;289:1537-1545.

41. FDA issues regulation prohibiting sale of dietary supplements containing ephedrine alkaloids and reiterates its advice that consumers stop using these products [press release]. February 6, 2004.

© 2007 Haymarket Media, Inc. and the American Academy of Physician Assistants. All rights reserved.
Use of jaapa.com subject to License agreement. Please read our Disclaimer and Privacy policy.