Physical Activity, Drugs, Surgery, and Other Treatments for Overweight and Obesity

Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it.

—Plato

One credible hypothesis about the source of the epidemic of overweight and obesity in the United States is the progressive decrease in physical activity expended in daily life—for work, transportation, and household chores. Some researchers contend that the average caloric intake of Americans has not substantially increased; instead, by reducing daily physical activity, the caloric imbalance between calories consumed and expended has shifted to favor weight gain. Even though no data conclusively prove this hypothesis, evidence does support it.

Among the recent studies that support the premise that Americans' sedentary lifestyle has precipitated the obesity epidemic is research that examined the diets of an Amish community in Ontario, Canada. In ''Physical Activity in an Old Order Amish Community'' (Medicine and Science in Sports and Exercise, vol. 36, no. 1, January 2004), David R. Bassett, Patrick L. Schneider, and Gertrude E. Huntington describe the ''Amish paradox''— that despite a diet that is high in fat, calories, and refined sugar, the Amish community had a scant 4% obesity rate, compared to 31% in the general U.S. population. The researchers chose this particular Amish population because it has rejected technological advances such as automobiles and electricity, and its physically demanding lifestyle is comparable to the way Americans lived 150 years ago. (Other Amish communities that have assumed occupations less physically active than farming have obesity rates that are similar to those found in the general U.S. population.) Bassett, Schneider, and Huntington analyzed the daily routines of about one hundred Amish people and found that men averaged about eighteen thousand steps per day and women about fourteen thousand, compared to the recommended ten thousand steps per day that most Americans struggle to achieve. The Amish men performed about ten hours per week of vigorous exercise and women spent about three-and-a-half hours engaged in heavy lifting, shoveling, digging, shoeing horses, or tossing straw bales. Men devoted an additional forty-three hours per week and women an average of thirty-nine hours to moderate physical activities such as gardening, performing farm-related chores, or doing laundry.

PHYSICAL ACTIVITY

In sharp contrast to the Amish farmers, many Americans are not physically active. The Centers for Disease Control and Prevention (CDC) defines in ''How Active Do Adults Need to Be to Gain Some Benefit?'' (May 22, 2007, http://www.cdc.gov/nccdphp/dnpa/physical/recommendations/adults.htm) the minimum recommended physical activity level for adults as ''moderate-intensity physical activity for 30 minutes or more on 5 or more days of the week, or vigorous-intensity physical activity for 20 minutes or more on 3 or more days of the week.'' Regardless, Table 6.1 shows that the percent of men and women that are physically inactive during leisure time increases with age and income. In 2004 more than half (52.7%) of adults aged sixty-five and older said they were physically inactive during leisure time, compared to about one-third (35.4%) of adults aged eighteen to forty-four. Women were more physically inactive than men of the same age across all age groups. However, the proportion of the U.S. population that reported no leisure-time physical activity has decreased from 31% in 1989 to 25% in 2005. (See Figure 6.1.)

The 2007 National Health Interview Survey data reveal that among adults aged eighteen to sixty-four who engage in regular leisure-time physical activity, the gender gap is closing, with comparable percentages of men and women reporting regular physical activity. (See Figure 6.2.) Figure 6.3 shows that non-Hispanic white adults (35%) were more likely than Hispanic adults (22%) and non-Hispanic African-American adults (20%) to participate in regular leisure-time physical activity.

Physical Activity and Weight Loss

Increasing physical activity and exercise is an important element of regimens intended to produce weight loss, even though the addition of exercise to a diet program generally does not produce substantially greater weight loss—most weight lost is attributable to decreased caloric intake. By favorably affecting blood lipids, increased and sustained physical activity does offer many direct and indirect health benefits, including reducing risks for cardiovascular heart disease and Type 2 diabetes beyond the risk reduction possible through diet alone. Physical activity lowers low-density lipoprotein (LDL) cholesterol and triglycerides, increases high-density lipoprotein (HDL) cholesterol, reduces abdominal fat as measured by waist circumference, and may protect against a decrease in muscle mass during weight loss.

Like those who have been inactive or sedentary, overweight people are advised to initiate physical activity slowly and gradually. Walking and swimming at a slow pace are ideal activities because they are enjoyable, easy to schedule, and less likely to produce injuries than many competitive sports. Table 6.2 is an example of a walking program that progressively increases physical activity. Furthermore, because amounts of activity and the resulting health benefits are functions of the duration, intensity, and frequency, the same amounts of activity may be obtained in longer sessions of moderately intense activity such as brisk walking than in shorter sessions of more strenuous activities such as running. Table 6.3 shows how a moderate amount of activity—physical activity that uses about 150 calories of energy per day for a total of about 1,000 calories per week—can be obtained in a variety of ways. Table 6.3 also indicates how performing common household chores, and even self-care activities such as using a wheelchair, may be used to fulfill requirements for moderate amounts of physical activity. Changing routines to include walking up stairs rather than taking an elevator or parking farther than usual from work, school, or shopping are ways to increase physical activity incrementally. Even reducing sedentary time, such as hours spent in front of the television or computer, can serve to increase energy expenditure.

Table 6.3 also shows the relationship between the intensity and duration of physical activities by comparing the amount of time a 154-pound adult must spend performing each activity to expend 150 calories. It is interesting to note that just five additional minutes of walking at a moderate pace expends the same number of calories as walking at a brisk pace.

In ''Effect of Exercise Duration and Intensity on Weight Loss in Overweight, Sedentary Women'' (Journal of the American Medical Association, vol. 290, no. 10, September 10, 2003), John M. Jakicic et al. of the University of Pittsburgh confirm the weight-loss benefits of even moderate exercise. The study divided 201 women aged twenty-one to forty-five into four groups. Two groups of women expended one thousand calories per week walking at a moderate pace for forty minutes per day. The other two groups expended two thousand calories per week; one group walked at a moderate pace for sixty minutes per day and the other at a vigorous pace for forty-five minutes per day. All the study participants reduced their calorie consumption to between twelve hundred and fifteen hundred calories per day. Jakicic et al. find no differences based on different exercise durations and intensities; one group of women lost almost as much weight—about thirteen to twenty pounds over twelve months—from walking at a moderate pace as another group did from walking at a brisk pace.

In another study, Cris A. Slentz et al. find in ''Effects of the Amount of Exercise on Body Weight, Body Composition, and Measures of Central Obesity: STRRIDE— A Randomized Controlled Study'' (Archives of Internal Medicine, vol. 164, no. 1, January 12, 2004) a close relationship between exercise and weight loss—increasing amounts of exercise yielded greater benefits. The study randomly assigned 182 sedentary, overweight adults aged forty to sixty-five to one of four groups: a control group with no exercise; supervised low-dose/moderate-intensity exercise equivalent to walking twelve miles per week; low-dose/vigorous-intensity exercise equivalent to jogging twelve miles per week; or high-dose/vigorous-intensity exercise equivalent to jogging twenty miles per week. The subjects were advised to maintain their weight and not to change their diets. Slentz et al. followed the subjects for eight months and then measured weight, body fat, waist circumference, and lean muscle mass.

Weight change was a 3.5% loss in the high-dose/ vigorous-intensity group and about a 1% loss in the two low-dose exercise groups, compared to a 1.1% gain in the control group. Increases in lean body mass were 1.4% in the two vigorous-intensity groups and 0.7% in the low-intensity group. Body fat mass increased by 0.5% in the control group and decreased by 2% in the low-dose/moderate-intensity group, by 2.6% in the low-dose/ vigorous-intensity group, and by 4.9% in the high-dose/ vigorous-intensity group. Waist circumference increased by 0.8% in the control group and decreased by 1.6% in the low-dose/moderate-intensity group, by 1.4% in the low-dose/vigorous-intensity group, and by 3.4% in the high-dose/vigorous-intensity group. The three exercise groups had also significantly decreased waist and hip circumference measurements compared to the control group.

RESEARCHERS RECONSIDER THE ROLE OF EXERCISE IN WEIGHT LOSS AND MAINTENANCE. In ''Long-Term Weight Losses Associated with Prescription of Higher Physical Activity Goals: Are Higher Levels of Physical Activity Protective against Weight Regain?'' (American Journal ofClinical Nutrition, vol. 85, no.4, April 2007), Deborah F. Tate et al. confirm that regular exercise and high levels of physical activity help maintain weight loss over time. However, does strenuous exercise really cause weight loss?

In an effort to answer this question, Neil A. King et al. asked thirty-five overweight people to exercise vigorously enough to burn five hundred calories per day for twelve weeks and reported their findings in ''Individual Variability Following 12 Weeks of Supervised Exercise: Identification and Characterization of Compensation for Exercise-Induced Weight Loss'' (International Journal of Obesity, September 11, 2007). Even though many of the subjects lost weight during the study, five gained weight-and there was not much variability between dietary changes made by subjects who lost as much as thirty pounds, those who lost just a few pounds, and those who gained. King et al. opine that their results demonstrate that there is considerable variability in the body's compensatory responses to exercise. In other words, moderate exercise may cause some people to lose weight, whereas others find that their weight is unchanged or even increases.

MEDICATION

Pharmacotherapy for weight loss involves the use of prescription drugs as one of several strategies including diet, physical activity, behavioral therapy, counseling, and participation in group-support programs that in combination can work to effect weight loss. Adding weight-loss medications to a comprehensive treatment program consisting of diet, physical activity, and counseling can increase weight loss by five to twenty pounds during the first six months of treatment. The decision to add prescription drugs to a treatment program usually considers the individual's body mass index (BMI), other medical problems, or coexisting risk factors. Table 6.4 shows the therapies appropriate for people with differing BMIs and takes into account the presence of comorbidities (the coexistence of two or more diseases) such as diabetes, severe obstructive sleep apnea, or heart disease.

Most drugs used for weight loss are anorexiants (appetite suppressants), which act on neurotransmitters (chemical substances that convey impulses from one nerve cell to another) in the brain. Anorexiant drugs vary depending on which neurotransmitters they affect: some

affect catecholamines such as dopamine and norepinephrine; others affect serotonin; and a third class of drugs acts on more than one neurotransmitter. The drugs act by increasing the secretion of dopamine, norepinephrine, or serotonin, by inhibiting reuptake of neurotransmitters, or by a combination of both mechanisms. For example, sibutramine inhibits the reuptake of norepinephrine and serotonin.

Another class of weight-loss drugs blocks the absorption of fat. Orlistat, which was approved by the U.S. Food and Drug Administration (FDA) in 1999, decreases fat absorption in the digestive tract by about one-third. Because it also inhibits absorption of water and vitamins, some users suffer from cramping and diarrhea.

Rimonabant, another weight-loss drug, acts on the endocannabinoid system to block the ''munchie receptor,'' which is believed to stimulate appetite among people who smoke marijuana. Because it blocks cravings, rimonabant has also been used to aid smoking cessation. Even though it is approved for use in Europe, at the close of 2007 the FDA had not granted marketing approval for the drug, largely due to reports of adverse side effects reported with its use, which were addressed in Rimonabant Briefing Document (June 13, 2007, http://www.fda.gov/ohrms/dockets/ac/07/briefing/2007-4306b1-fda-backgrounder.pdf).

The determination of which type of drug to prescribe is based on individual patient characteristics—sibutramine works best for people who are preoccupied with food and feel constantly hungry, orlistat may be effective for those who are unwilling to reduce fat from their diet, and rimonabant may help reduce food cravings. Even though drug therapy has not demonstrated remarkable effectiveness, only modestly enhancing weight loss over diet alone, consumer demand for weight-loss drugs is high. In February 2007 the FDA approved the over-the-counter (nonprescription) sale of orlistat.

Several weight-loss drugs that appeared effective and were popular among consumers have been withdrawn from the U.S. market due to the number and severity of adverse side effects associated with their use. During the 1990s a combination of two drugs—phentermine and fenfluramine, commonly known as ''phen-fen''—was prescribed for long-term use (more than three months); however, rare but unacceptable side effects, including serious damage to the heart valves, prompted the withdrawal of fenfluramine and a similar drug, dexfenfluramine, in September 1997. Phentermine is still approved for short-term use.

In ''Effective Obesity Treatments'' (American Psychologist, vol. 62, no. 3, April 2007), Lynda H. Powell, James E. Calvin III, and James E. Calvin Jr. evaluate the results of published studies of the efficacy (effectiveness) of obesity treatments and conclude that ''drug interventions result in modest weight loss with minimal risks but disproportionate clinical benefit. Combinations of lifestyle, drug, and, where appropriate, surgical interventions may be the most efficacious approach to achieving sustained weight loss for the widest diversity of patients.''

Research Focuses on New Weight-Loss Drugs

By the close of 2007, only two weight-loss drugs, orlistat and sibutramine, were FDA-approved for long-term use, and evidence indicates that many users experience ''rebound'' weight gain when the use of either of these drugs is discontinued. During 2007, however, more than a dozen new drugs were in various stages of development.

Researchers have identified that the hormone ghrelin may be involved in establishing hunger and satiety (the feeling of fullness or satisfaction after eating) set points. When the stomach is empty, it releases ghrelin, which in turn triggers hunger signals in the brain. Blood levels of ghrelin peak before meals and decrease after eating. Because ghrelin appears to increase appetite and slow metabolism, an excess of it may sabotage long-term weight-loss efforts. Small studies show that ghrelin levels are higher in obese patients who have recently lost weight, compared to obese patients at a steady weight. In recent years, pharmaceutical companies have been seeking to create drugs that safely and effectively block ghrelin's effects. According to the article ''Nastech Submits Investigational New Drug Application for PYY3-36 Nasal Spray to Treat Obesity'' (Medical News Today, June 9, 2006), an analogous approach seeks to boost levels of a peptide known as PYY that produces the opposite effects of ghrelin. After eating, the stomach and digestive tract release PYY, conveying the satiety signal to the brain.

Mike Nagle reports in ''Genaera Begins Human Trials of Obesity Drug'' (DrugResearcher.com, August 5, 2007) that a new appetite-suppressing drug called trodusquemine was undergoing clinical trials in 2007. Trodusquemine is the first highly selective inhibitor of the protein tyrosine phosphatase 1B (PTP1B). In preclinical testing on obese mice, trodusquemine suppressed appetite, caused weight loss, and normalized fasting blood glucose and cholesterol levels.

Gabriele E. Sonnenberg, Glenn Matfin, and Rickey R. Reinhardt indicate in ''Drug Treatments for Obesity: Where Are We Heading and How Do We Get There?'' (British Journal of Diabetes and Vascular Disease,vol. 7, no, 3, 2007) that more effective drug therapy will likely target multiple systems, such as the gastrointestinal (digestive) system as well as the endocrine and neurological pathways. There is also enthusiasm for the development of a drug that increases the body's metabolic rate because it might enable people to forgo severely restricted diets and still realize weight loss.

Nonprescription Weight-Loss Aids

The withdrawal of fenfluramine from the market prompted many consumers to seek alternative weight-loss aids, including herbal preparations that were marketed as dietary supplements and available over the counter. Some preparations combined ephedra, caffeine, and other ingredients. Ephedra (also known by its traditional Chinese medicine name, ma huang) is a naturally occurring substance that comes from botanicals. Products containing ephedra and ephedrine have been promoted to accelerate weight loss, increase energy, and improve athletic performance. The principal active ingredient in ephedrine is an amphetamine-like compound that stimulates the nervous system and heart. Because ephedrine has some anorectic and thermogenic properties, it may induce weight loss in some people, and some studies show that when ephedrine is combined with caffeine, the combination may lead to even more weight loss.

During 2003 the FDA and the National Institutes of Health (NIH) investigated reports of adverse effects linked to ephedra use. In Ephedra and Ephedrine for Weight Loss and Athletic Performance Enhancement: Clinical Efficacy and Side Effects (February 2003, http://www.ahrq.gov/downloads/pub/evidence/pdf/ephedra/ephedra.pdf), Paul Shekelle et al. of the RAND Corporation conclude that there is only limited evidence of health benefits resulting from ephedra use. These benefits do not outweigh the serious risks posed by its association with heart palpitations, psychiatric and upper gastrointestinal effects, tremors, and insomnia, especially in formulations in which it was combined with caffeine or taken with other stimulants. Shekelle et al. reviewed sixteen thousand adverse events and identified one seizure, two deaths, four heart attacks, five psychiatric cases, and nine strokes in which ephedra appeared to be the causative agent.

In another study, ''The Relative Safety of Ephedra Compared with Other Herbal Products'' (Annals of Internal Medicine, vol. 138, no. 6, March 18, 2003), Stephen Bent et al. compare the risk for adverse events attributable to ephedra and other herbal products. The researchers find that even though ephedra products comprised 0.8% of all dietary supplement sales, they accounted for 64% of adverse events associated with dietary supplements. Bent et al. conclude that ''the risk for an adverse reaction after the use of ephedra is substantially greater than with other herbal products.''

According to the press release ''FTC Charges Direct Marketers of Ephedra Weight Loss Products with Making Deceptive Efficacy and Safety Claims'' (July 1, 2003, http://www.ftc.gov/opa/2003/07/ephedra.shtm), in July 2003 the Federal Trade Commission (FTC) charged marketers of weight-loss products that contain ephedra with making deceptive efficacy and safety claims. The FTC deemed as examples of false advertising claims that ephedra causes rapid, substantial, and permanent weight loss without diet or exercise, and that ''clinical studies'' or ''medical research'' proved these claims. The FTC also challenged claims that the ephedra weight-loss products are ''100% safe,'' ''perfectly safe,'' or have ''no side effects.''

The press release ''FDA Announces Plans to Prohibit Sales of Dietary Supplements Containing Ephedra'' (http://www.hhs.gov/news/press/2003pres/20031230.html) notes that on December 30, 2003, the U.S. Department of Health and Human Services and the FDA notified manufacturers of dietary supplements containing ephedra that the sale of these dietary supplements would be banned sixty days following publication of the year-end notice. That same day, the FDA issued an alert to consumers advising them to stop using ephedra products immediately.

In early 2004 dieters flocked to health food stores and Internet sites selling dietary supplements and bought entire inventories of supplements containing ephedra in anticipation of the ban of its sale. Many of the supplements' fans asserted that the ban was prompted by the publicity surrounding the ephedra-related death of the Baltimore Orioles pitcher Steve Bechler on February 17, 2003. Bechler was twenty-three years old when he collapsed from heatstroke at the Orioles' spring training camp in Florida. Two weeks later, the FDA ordered warning labels be placed on products containing ephedra and set in motion plans to ban its sale.

Many health professionals and consumer watchdog agencies applauded the FDA action. However, they also observed that the FDA first proposed warning labels and a dosage curb for ephedra in 1997, but the supplement industry effectively blocked the move. The December 2003 action was a historic occasion-it was the first time the FDA completed the steps necessary to ban the sale of a dietary supplement.

WILL HOODIA BE THE NEXT BEST THING FOR DIETERS? With ephedra withdrawn from the market, dieters waited for the introduction of another nonprescription drug to replace it. In 2003 reports of an appetite suppressant derived from hoodia, a bitter-tasting cactus that grows in the South African Kalahari desert, generated interest. The San Bushmen of the Kalahari, one of the world's oldest and most primitive tribes, have been eating hoodia for thousands of years to stave off hunger during long hunting trips.

The plant contains the molecule p57, which is thought to act on the hypothalamus to mimic the sense of satiety that normally results only from eating food. The first clinical trials of hoodia were considered successful when subjects given hoodia consumed an average of one thousand calories fewer per day than those given a placebo. By 2007 dozens of Web sites offered pills, powders, and liquids containing various amounts of hoodia.

SURGERY

Weight-loss surgery is considered a treatment option only for people for whom all other treatment methods have failed and who suffer from clinically severe obesity-BMI of 40 or greater or BMI of 35 or greater in the presence of comorbidities. (Clinically severe obesity was formerly known as morbid obesity, indicating its potential to cause disease.) Two types of surgical procedures have been demonstrated effective in producing weight loss maintained for five years: restrictive techniques, which restrict gastric volume, and malabsorptive procedures, which not only limit food intake but also alter digestion. An example of the first type is banded gastroplasty, in which an inflatable band that can be adjusted to different diameters is placed around the stomach. The Roux-en-Y gastric bypass is an example of the second type. (See Figure 6.4.) On average, patients maintain a weight loss of 25% to 40% of their preoperative body weight after these procedures.

The surgery not only improves patients' quality of life by causing weight loss and the resolution of many weight-related conditions such as sleep apnea, joint pain, and diabetes, but also reduces their risk of death. Lars Sjöström et al. find in ''Effects of Bariatric Surgery on Mortality in Swedish Obese Subjects'' (New England Journal of Medicine, vol.357, no, 8, August 23, 2007), a study following 2,010 bariatric surgery patients and a control group consisting of 2,037 obese subjects who did not have surgery, that bariatric surgery was associated with a reduction in overall mortality.

Because the surgical procedures are not without risk, physicians generally recommend surgery only when the risks of obesity far outweigh the risks associated with the surgery. The National, Heart, Lung, and Blood Institute explains that surgical complications vary depending on the weight and overall health of the surgical patient. According to Daniel Leslie, Todd A. Kellogg, and Sayeed Ikramuddin, in ''Bariatric Surgery Primer for the Internist: Keys to the Surgical Consultation'' (Medical Clinics of North America, vol. 91, no. 3, May 2007), young people without comorbidities and a BMI equal to or less than 50 have the lowest reported mortality rates— less than 1%. Not unexpectedly, those with a BMI equal to or greater than 60 with comorbidities such as diabetes or high blood pressure have higher mortality rates.

People who undergo weight-loss surgeries require lifelong medical monitoring. After surgery, they are no longer able to eat in the way to which they were accustomed. Those who have undergone gastric bypass experience ''dumping syndrome'' with symptoms such as sweating, palpitations, lightheadedness, and nausea when they ingest significant amounts of calorie-dense food, and most become conditioned not to eat such foods. Patients who have had gastric restriction surgery are unable to eat more than a limited amount of food at a single sitting without vomiting, so they must eat several small meals per day to maintain adequate nutrition. Those who do not adhere to a prescribed regimen of vitamins and minerals may develop vitamin and iron deficiencies. There are also postoperative and long-term complications of surgery such as wound infections, problems such as hernias at the incision site, and gallstones. Generally, however, patients fare extremely well, experiencing dramatic improvement and even complete resolution of diabetes, hypertension (high blood pressure), and infertility, as well as improved mobility, self-esteem, and overall quality of life.

The article ''Gastric Bypass Surgery May Cause Post-op Nutrient Deficiencies'' (Reuters Health Information. October 15, 2007) notes that besides the possibility of nutritional deficiencies, research reveals that bypass surgery may cause a condition known as ''small intestinal bacterial overgrowth,'' which interferes with nutrient absorption. Deficiencies in vitamin D, calcium, and zinc may in turn increase the risk of developing other serious conditions such as hypothyroidism (deficiency of the thyroid hormone, which is produced by the thyroid gland) and osteoporosis.

In ''Death Rates and Causes of Death after Bariatric Surgery for Pennsylvania Residents, 1995 to 2004'' (Archives of Surgery, vol. 142, no. 10, October 2007), a study of more than sixteen thousand patients who had undergone bariatric surgery, Bennet I. Omalu et al. report an excessive number of patient deaths attributable to coronary artery disease and suicide. Heart disease was the leading cause of death and was responsible for 20% of deaths that occurred thirty days or more after the surgery. This rate is nearly three times higher than in the general population. Another 7% of deaths were attributable to suicide or drug overdose, and the researchers speculate that continued obesity and/or weight regain might have contributed to both the heart disease and suicide deaths.

Number of Surgeons and Surgeries Soars

Nanci Hellmich states in ''Study: Gastric Bypass Reduces Death Risk in the Morbidly Obese'' (USA Today, August 22, 2007) that 23,100 bariatric procedures were performed in 1997; by 2007 the number was estimated to be more than 205,000. For thousands of patients, weight-loss surgery has eliminated debilitating diseases and improved their quality of life. With the number of candidates for bariatric surgery increasing, the number of procedures is expected to continue to grow, even in view of data that reveal that the risks may be greater than previously believed.

In ''Assessing the Value of Weight Loss among Primary Care Patients'' (Journal of General Internal Medicine, vol. 19, no. 12, December 2004), Christina C. Wee et al. find that even the risk of death does not dissuade many patients from undergoing bariatric surgery. In an effort to quantify the value people place on modest weight loss, the researchers interviewed 365 patients at a large hospital-based primary care practice, one-third of whom were obese. The subjects were asked to imagine a treatment that would guarantee them effort-less weight loss of varying amounts of weight. For each amount, they were asked if they would be willing to accept a risk of death to achieve it. If so, how much of a risk of death?

Willingness to risk death or trade years of life to lose weight significantly increased with higher BMI, and the more weight the subjects imagined they could lose, the greater the risk they would take to achieve it. Eighteen percent of overweight and 33% of obese people said they would risk death for even a modest 10% weight loss, compared to just 4% of normal-weight subjects willing to risk death to lose 10% of their weight.

Many of the overweight and obese participants in the survey also said they would give up some of their remaining years of life if they could live those years weighing slightly less. Thirty-one percent of obese patients and 8.3% of overweight patients said they would trade up to 5% of their remaining life to be 10% thinner. Wee et al. conclude that many people, especially those who are obese, value modest weight loss and suggest that physicians emphasize the benefits of modest weight loss when counseling their patients.

COUNSELING AND BEHAVIORAL THERAPY

Weight-loss counseling and behavioral therapy aim to assist people to develop the skills needed to identify and modify eating and activity behaviors, and change thinking patterns that undermine weight-control efforts. Behavioral strategies include self-monitoring of weight, food intake, and physical activity; identifying and controlling stimuli that provoke overeating; problem identification and problem solving; and using family and social support systems to reinforce weight-control efforts. Counseling and behavioral therapy are often perceived as necessary components of comprehensive weight-loss treatment, but are also viewed as labor intensive because educating and supporting people seeking to lose weight is time consuming. The effort also requires the active participation of everyone who may be involved in treatment—the affected individuals, their families, physicians, nurses, nutritionists, dieticians, exercise instructors, and mental health professionals. In view of the considerable resources that must be allocated to deliver counseling and behavioral therapy, it is important to know if these approaches effectively promote weight loss.

Kathleen M. McTigue et al. considered the evidence supporting the efficacy of counseling and behavioral therapy as well as other treatment methods and reported their findings in ''Screening and Interventions for Obesity in Adults: Summary of the Evidence for the U.S. Preventive Services Task Force'' (Annals of Internal Medicine, vol. 139, no. 11, December 2, 2003). The investigators report that counseling to promote change in diet, exercise, or both, and behavioral therapy to help patients acquire the skills, motivations, and support to change diet and exercise patterns enabled obese patients to achieve modest but clinically significant and sustained (one to two years) weight loss. Furthermore, they observe that because control groups also frequently received some form of counseling, education, or support, they might have underestimated the effectiveness of counseling. Not unexpectedly, more intensive programs, with more frequent contact, were generally more successful, as were those incorporating behavioral therapy.

Interestingly, McTigue et al. find that treating patients on an individual basis rather than on a group basis did not appear to affect outcomes. This finding offers credence to the theory that the benefits of mutual aid and peer support provided by group programs may be as powerful as the personalized, one-to-one attention afforded patients in individual counseling sessions. If this is true, then group programs might be a laborsaving, cost-effective alternative to individual weight-loss counseling.

McTigue et al. conclude that ''all obesity therapies carry promise and burden, which must be balanced in clinical decision-making. Counseling approaches appear the least harmful and produce modest, clinically important weight loss, but entail cost in time and resources. Pharmacotherapy promotes modest additional weight loss, but long-term drug use may be needed to sustain this benefit with unknown long-term adverse events and appreciable cost. Only surgical options consistently result in large amounts of long-term weight reduction; however, they carry a low risk for severe complications and are expensive. Body size, health status, and prior weight-loss history may all influence obesity treatment.''

Comparing Weight-Loss Using a Self-Help Program and a Commercial Program

Stanley Heshka et al. report the results of their research to determine the efficacy of commercial weight-loss programs in ''Weight Loss with Self-Help Compared with a Structured Commercial Program'' (Journal of the American Medical Association, vol. 289, no. 14, April 9, 2003). Their study randomly assigned one group of obese men and women to a self-help program consisting of two twenty-minute counseling sessions with a nutritionist and provision of self-help resources such as public library materials, Web sites, and telephone numbers of health organizations that offered free weight-control information. The other group was assigned to attend Weight Watchers, a commercial weight-loss program consisting of a food plan, an exercise plan consistent with NIH-recommended physical activity guidelines, regular weight monitoring, printed educational materials, and a behavior modification plan, delivered at weekly meetings.

Subjects were evaluated regularly during the course of the two-year study—at 12, 26, 52, 78, and 104 weeks. The primary outcome measure used to evaluate the effectiveness of the programs was change in body weight; however, BMI, waist circumference, and body fat as quantified by bioimpedance analysis (electrical resistance) were also recorded. Other secondary measures were blood pressure, total cholesterol, HDL cholesterol, triglycerides, insulin, and quality of life measured using the ''Medical Outcomes Study Short-Form 36 Health Survey and Impact of Weight on Quality of Life Questionnaire.''

After one year of participation in the study, subjects in the commercial program had greater weight loss than those in the self-help group. Similarly, waist circumference and BMI decreased more in the commercial group than in the self-help group. Blood pressure and serum insulin showed greater improvement in the commercial group, compared to the self-help group at year one, but only insulin was significantly different at year two. Total cholesterol and the HDL/total cholesterol ratio improved in both groups. The commercial group maintained a weight loss of 9.5 to 11 pounds at the end of the first year and was 5.9 to 6.6 pounds lower than its initial weight at the end of the second year. Subjects who attended 78% or more of the commercial group sessions maintained a mean weight loss of almost 11 pounds at the end of the two-year study. Heshka et al. conclude that even though the structured commercial weight-loss program provided only modest weight loss, it was more effective than brief counseling and self-help for over-weight and obese adults over a two-year period.

Weight-Loss Counseling to Change Behavior

The NIH designed a practical protocol, known as an algorithm, for obtaining and organizing information necessary for effective weight-loss counseling. The algorithm is based on the ''five As'':

• Assessing obesity risk
• Asking about readiness to lose weight
• Advising about a weight-control program
• Assisting to establish appropriate intervention
• Arranging for follow-up

The National Heart, Lung, and Blood Institute recommends in Practical Guide to the Identification, Evaluation,and Treatment of Overweight and Obesity in Adults (October 2000, http://www.nhlbi.nih.gov/guidelines/obesity/prctgd_c.pdf) that health-care professionals consider a variety of psychosocial, environmental, and health-related issues when performing a ''behavioral assessment'' of an individual for whom weight loss is indicated. These issues include:

• Whether the individual is seeking to lose weight on his or her own or in response to pressure from family members, an employer, or a physician. This is an important consideration because people who feel coerced into seeking weight-loss treatment are not as likely to achieve success as those who seek it on their own initiative.
• Identifying the source of the individual's desire to lose weight to better understand his or her motivation and goals. Because many people have suffered from overweight or obesity for years before seeking treatment, pinpointing the stimulus to lose weight can assist the health-care professional to motivate and support the individual's weight-loss efforts.
• Assessing the individual's stress level to determine if external stressors such as family-, financial-, or work-related problems might prevent the individual from concentrating on weight loss. It is also important to determine if the individual is suffering from depression or other mental health problems because it is usually advisable to treat mood disorders or other mental health problems before embarking on a weight-loss program.
• Evaluating the individual for the presence of an eating disorder such as binge eating that may coexist with overweight or obesity. People suffering from eating disorders are more likely to require psychological treatment and nutritional counseling to ensure the success of weight-loss programs than those who do not have eating disorders.
• Determining the individual's understanding of the lifestyle and other changes required for weight loss. The success of treatment hinges on the individual's ability to successfully make the required changes, so it is vital to develop a treatment plan that includes realistic activities such as gradually increasing physical activity that the individual agrees are attainable.
• Setting and agreeing on realistic weight-loss goals and objectives. If an obese individual has unrealistic expectations about the amount of weight that will be lost, then he or she may become discouraged and abandon efforts to lose weight. Health professionals should temper unrealistic expectations by informing individuals about the considerable health and lifestyle benefits of even modest weight loss.

Successful weight loss is more likely to occur when health-care professionals—physicians, nurses, nutritionists, dieticians, and mental health professionals—actively involve people seeking to lose weight in a collaborative effort to establish short-term goals and attain them. ''Shaping'' is a behavioral technique in which a series of short-term objectives are identified that ultimately lead to a treatment goal, such as incrementally increasing physical activity from ten minutes per day to forty-five minutes per day over time. ''Self-monitoring'' is the practice of observing and recording behaviors such as caloric intake, food choices, amounts consumed, and emotional or other triggers to eat as well as physical activity performed and daily or weekly monitoring of body weight.

Finally, the National Heart, Lung, and Blood Institute reminds health professionals to acknowledge the challenges of accomplishing weight loss and encourages everyone involved in treatment to ''focus on positive changes and adapt a problem-solving approach toward shortfalls. . . . Emphasize that weight control is a journey, not a destination, and that some missteps are inevitable opportunities to learn how to be more successful.''

Weight-Loss Counseling Online

An expanding array of diet, counseling, and support group programs are available on the Internet; however, little research has compared them or determined their efficacy. In ''A Randomized Trial Comparing Human E-Mail Counseling, Computer-Automated Tailored Counseling, and No Counseling in an Internet Weight Loss Program'' (Archives of Internal Medicine, vol. 166, no. 15, 2006), Deborah F. Tate, Elizabeth H. Jackvony, and Rena R. Wing sought to determine whether computer-generated feedback, delivered via the Internet, would prove to be a viable alternative to human counseling via e-mail. They compared the effects of custom-tailored computer-automated interactions with an Internet program that provided weight-loss counseling from a human via e-mail.

All the subjects received one weight-loss group session, coupons for meal replacements, and access to an interactive Web site. The human e-mail counseling and computer-automated feedback groups also had access to an electronic diary and message board. The human e-mail counseling group received weekly e-mail feedback from a counselor, the computer-automated feedback group received automated, custom-tailored messages, and a control group received no counseling at all. Recommendations included calorie-restricted diets of between twelve hundred and fifteen hundred calories per day, daily exercise equivalent to walking for thirty minutes, and instructions about how to use meal replacement products. All participants were encouraged to self-monitor their diets and exercise using diaries and calorie books. Both groups accessed the same Web site, which featured weekly reporting and graphs of weight, weekly e-mail prompts to report weight, weekly weight-loss tips via e-mail, recipes, and a weight-loss e-buddy network system that enabled users to interact with other dieters with similar characteristics via e-mail.

The primary outcome measure used to compare the groups was change in body weight from baseline and at three and six months. Both the human and automated e-counseling groups had greater reductions in weight than the control group at each weigh-in. Tate, Jackvony, and Wing conclude that automated computer feedback was as effective as human e-mail counseling.

Complementary and Alternative Therapies

Many complementary and alternative medicine practices such as yoga, Dahn—a holistic mind-body training method—and ''mindful eating,'' which teaches greater awareness of bodily sensations such as hunger and satiety and helps people identify ''emotional eating,'' have been used to promote weight loss. Acupuncture (the Chinese practice of inserting extremely thin, sterile needles into any of 360 specific points on the body) and hypnosis are, however, the only alternative medical practices that have been studied as potential treatments for obesity. Several studies report that acupuncture does not appear to have any benefit greater than a placebo.

Hypnosis is an altered state of consciousness. It is a state of heightened awareness and suggestibility and enables focused concentration that may be used to alter perceptions of hunger and satiety and to modify behavior. Hypnosis is considered a mainstream treatment for addictions and overeating. There are conflicting data about its effectiveness—some studies find that it adds little, if any, benefit beyond that of placebo. Others conclude that hypnosis may have some initial benefit for people seeking weight loss, but that it has little sustained effect.

In ''Complementary Therapies for Reducing Body Weight: A Systematic Review'' (International Journal of Obesity, vol. 29, no. 9, 2005), Max H. Pittler and Edzard Ernst review the published literature describing a variety of complementary and alternative medicine therapies for weight loss. They find that subjects receiving hypnotherapy lost more weight than subjects in a control group that did not receive hypnotherapy; that the addition of hypnotherapy to cognitive behavioral therapy led to a small reduction in body weight; and that patients in a small hypnotherapy group aimed at stress management lost significantly more weight than those in a control group.

MIGHT WEIGHT LOSS BE HARMFUL?

Successful weight-loss treatments generally result in reduced blood pressure, reduced triglycerides, increased HDL cholesterol, and reduced total cholesterol and LDL cholesterol. Weight loss of as little as 5% to 10% of initial weight produces measurable health benefits and may prevent illnesses among people at risk. These findings suggest that treatment should not exclusively focus on the medical consequences of obesity, but that obesity itself should be treated. The NIH recommends weight loss for people with a BMI greater than 30 and for those with a BMI greater than 25 with two or more obesity-related risk factors. The NIH guidelines recommend that for people with a BMI between 25 and 30 without other risk factors, the focus should be on prevention of further weight gain, rather than on weight loss.

In ''Obesity: What Mental Health Professionals Need to Know'' (American Journal of Psychiatry, vol.157,no. 6, June 2000), Michael J. Devlin, Susan Z. Yanovski, and G. Terence Wilson report that critics cite the health and psychological risks of weight cycling (the repeated loss and regain of body weight) as even greater than the risks associated with obesity. They assert that multiple unsuccessful efforts to lose weight demoralize people and make future weight loss even more challenging, and that the dietary treatment of obesity may trigger or worsen binge eating among people who are obese. Devlin, Yanovski, and Wilson also offer several studies that find an association between weight cycling and increased morbidity and mortality as evidence of the dangers of dieting.

In ''Screening and Interventions for Obesity in Adults: Summary of the Evidence for the U.S. Preventive Services Task Force'' (Annals of Internal Medicine, vol. 139, no. 11, 2003), Kathleen M. McTigue et al. review the studies that reveal a link between weight cycling and mortality. The investigators find that some studies failed to distinguish between intentional and unintentional weight loss. In the research considering the relationship between weight cycling with intentional weight loss, some studies found unfavorable effects on coronary heart disease and its risk factors and others did not. McTigue et al. also find data suggesting that a weight-cycling risk increases inversely with BMI-the higher the BMI, the lower the risk of weight cycling. If these findings are correct, then people suffering from obesity as opposed to overweight are at less risk of morbidity and mortality attributable to weight cycling.

Is It Better to Be Overweight?

Two studies indicate that there is less risk associated with overweight than previously thought. The first, Katherine M. Flegal et al.'s ''Excess Deaths Associated with Underweight, Overweight, and Obesity'' (Journal of the American Medical Association, vol. 293, no. 15, April 20, 2005), finds that increased risk of death from obesity was mostly among the extremely obese, a group constituting just 8% of Americans. The researchers also find that extreme thinness carried a slight increase in the risk of death. Flegal et al.'s study does not explain how or why being slightly overweight affords protection, but they speculate that it is because most people die when they are over seventy. Being mildly overweight in old age may be protective, because it gives rise to more muscle and bone.

The second study, ''Secular Trends in Cardiovascular Disease Risk Factors According to Body Mass Index in U.S. Adults'' (Journal of the American Medical Association, vol. 293, no.15, April 20, 2005) by Edward W. Gregg et al., examines forty-year trends in cardiovascular disease (CVD) risk factors by BMI groups among adults aged twenty to seventy-four years and finds that except for diabetes, CVD risk factors have declined considerably over the past forty years in all BMI groups. Even though obese people still have higher risk-factor levels than lean people, the levels of these risk factors are much lower than in previous decades. Gregg et al. observe that obese people in the twenty-first century have better CVD risk-factor profiles than their leaner counterparts did twenty to thirty years ago; however, they suggest that other factors, such as effective treatment to reduce cholesterol and blood pressure as well as the decreased prevalence of smoking, might explain the improved profiles of obese people.