Dietary Therapy
In the majority of overweight and obese patients, adjustment of the diet to reduce caloric intake will be required. Dietary therapy consists, in large part, of instructing patients on how to modify their diets to achieve a decrease in caloric intake. A key element of the current recommendation is the use of a moderate reduction in caloric intake to achieve a slow but progressive weight loss. Ideally, caloric intake should be reduced only to the level required to maintain weight at the desired level. If this level of caloric intake is achieved, excess weight will gradually disappear. In practice, somewhat greater caloric deficits are used in the period of active weight loss, but diets with very low calories are to be avoided. Finally the composition of the diet should be modified to minimize other cardiovascular risk factors.
The centerpiece of dietary therapy for weight loss in overweight patients is a low-calorie diet (LCD) (800 to 1,500 kcal/day). This diet is to be distinguished from a very low-calorie diet (VLCD) (250 to 800 kcal/day), which has been unsuccessful in achieving weight loss over the long term. The LCD recommended in this report also contains nutrient compositions that will decrease other risk factors, notably, high serum cholesterol and hypertension.
Evidence Statement: LCDs can reduce total body weight by an average of 8 percent and help reduce abdominal fat content over a period of approximately 6 months. Evidence Category A.
Rationale: A decrease in calorie intake is the most important dietary component of weight loss and maintenance. LCDs have been shown to reduce total body weight by an average of 8 percent over a period of 6 months, accompanied by significant reductions in waist circumference. Since this represents an average that includes individuals who did not lose weight, an individual average goal of 10 percent is feasible.
When weight loss occurs, the loss consists of about 75 percent fat and 25 percent lean tissue. A deficit of 500 to 1,000 kcal/day will produce a weight loss of 70 to 140 grams/day, or 490 to 980 grams/week (1 to 2 lb/week). A deficit of 300 to 500 kcal/day will produce a weight loss of 40 to 70 grams/day, or 280 to 490 grams/week (1/2 to 1 lb/week) A patient may choose a diet of 1,000 to 1,200 kcal for women and 1,200 to 1,500 kcal for men.
VLCDs (less than 800 kcal/day) are not recommended for weight loss therapy because the deficits are too great, and nutritional inadequacies will occur unless VLCDs are supplemented with vitamins and minerals. Moreover, clinical trials show that LCDs are just as effective as VLCDs in producing weight loss after 1 year. Although more weight is initially lost with VLCDs, more is usually regained. Further, rapid weight reduction does not allow for gradual acquisition of changes in eating behavior. Successful behavior therapy is the key to longterm maintenance of weight at a reduced level. Finally, patients using VLCDs are at increased risk for developing gallstones.
Successful weight reduction by LCDs is more likely to occur when consideration is given to a patient's food preferences in tailoring a particular diet. Care should be taken to be sure that all of the recommended dietary allowances are met; this may require use of a dietary supplement. Dietary education is a necessary ingredient in achieving adjustment to an LCD. Educational efforts should pay particular attention to the following topics:
 | energy value of different foods; |
| food composition fats, carbohydrates (including dietary fiber), and proteins; |
| reading nutrition labels to determine caloric content and food composition; |
| new habits of purchasing preference to low calorie foods; |
| food preparation avoiding adding high-calorie ingredients during cooking (e.g., fats and oils); |
| avoiding over consumption of high-calorie foods (both high-fat and high-carbohydrate foods); |
| maintain adequate water intake |
| reducing portion sizes; and |
| limiting alcohol consumption. |
The Step I Diet in ATP II provides an appropriate nutrient composition for an LCD diet. The composition of the diet is presented in Table 4.
Recommendation: A diet that is individually planned to help create a deficit of 500 to 1,000 kcal/day should be an integral part of any program aimed at achieving a weight loss of 1 to 2 lb/week. Evidence Category A.
Recommendation: Reducing dietary fat alone without reducing calories is not sufficient for weight loss. However, reducing dietary fat, along with reducing dietary carbohydrates, can facilitate caloric reduction. Evidence Category A.
Evidence Statement: Optimally, dietary therapy should last at least 6 months.
Evidence Category A.
Rationale: Many studies suggest that the rate of weight loss diminishes after about 6 months. Shorter periods of dietary therapy usually result in lesser weight reductions. Therapeutic efforts should be directed toward behavior therapy as well as maintaining LCDs.
Evidence Statement: During dietary therapy, frequent contacts between professional counselors and patients promote weight loss and maintenance. Evidence Category C.
Rationale: Frequent clinical encounters during the initial 6 months of weight reduction appear to facilitate reaching the goals of therapy. During the period of active weight loss, regular visits of at least once per month and preferably more often with a health professional for the purposes of reinforcement, encouragement, and monitoring will facilitate weight reduction. Weekly group meetings can be conducted at a low cost, and can contribute to favorable behavior changes. However, no clinical trials have been specifically designed to test the relative efficacy of different frequencies of encounters with physicians, dietitians, or others in the weight loss team.
Evidence Statement: The amount of time spent with the patient favorably affects weight change in overweight or obese adults given dietary therapy. Evidence Category D.
Rationale: Training of a health professional in techniques of weight reduction, especially in behavior therapy and dietary principles, is expected to facilitate weight reduction. Further, adequate time must be made available to the patient to convey the information necessary, to reinforce behavioral and dietary messages, and to monitor the patient's response. Despite these judgments, none of the studies reviewed were designed to specifically address the type or qualifications of the health professional who implemented the various weight loss approaches. Many of the studies differed in the types of
Recommendation: The literature suggests that weight loss and weight maintenance therapies that provide a greater frequency of contacts between the patient and the practitioner and are provided over the long term should be put in place. This can lead to more successful weight loss and weight maintenance. Evidence Category C.
Physical Activity
An increase in physical activity is an important component of weight loss therapy since it leads to increased expenditure of energy. Increased physical activity may also inhibit food intake in overweight patients. Physical activity can also be helpful in maintaining a desirable weight. In addition, sustained physical activity has the benefit of reducing overall CHD risk beyond that produced by weight reduction alone.
Several experts believe that a progressive decrease in the amount of energy expended for work, transportation, and personal chores is a major cause of obesity in the United States. These authorities note that total caloric intake has not increased over the last few decades; instead, the caloric imbalance leading to overweight and obesity is the result of a substantial decrease in physical activity and, consequently, a decrease in daily energy expenditure. However, this hypothesis is difficult to prove because appropriate data are lacking. Successful restoration of normal weight in many overweight and obese persons requires a higher level of energy expenditure. Increased regular physical activity is the way to achieve this goal of augmenting daily energy expenditure.
| Table 4: Low Caloried Step 1 Diet |
| Nutrient |
Recommended Intake |
| Calories1 |
Approximately 500 to 1,000 kcal/day reduction from usual intake |
| Total Fat2 |
30 percent or less of total calories |
| Saturated Fatty Acids3 |
8 to 10 percent of total calories |
| Monounsaturated Fatty Acids |
Up to 15 percent of total calories |
| Polyunsaturated Fatty Acids |
Up to 10 percent of total calories |
| Cholesterol3 |
< 300 mg/day |
| Protein4 |
Approximately 15 percent of total calories |
| Carbohydrate5 |
55 percent or more of total calories |
| Sodium Chloride |
No more than 100 mmol per day (approximately 2.4 g of sodium or approximately 6 g of sodium chloride) |
| Calcium6 |
1,000 to 1,500 mg |
| Fiber5 |
20 to 30 g |
|
|
- A reduction in calories of 500 to1,000 kcal/day will help achieve a weight loss of 1 to 2 lbs/week. Alcohol provides unneeded calories and displaces more nutritious foods. Alcohol consumption not only increases the number of calories in a diet but has been associated with obesity in epidemiological studies 559-562 as well as in experimental studies. 563-566 The impact of alcohol calories on a person's overall caloric intake needs to be assessed and appropriately controlled.
- Fat-modified foods may provide a helpful strategy for lowering total fat intake but will only be effective if they are also low in calories and if there is no compensation of calories from other foods.
- Patients with high blood cholesterol levels may need to use the Step II diet to achieve further reductions in LDL-cholesterol levels; in the Step II diet, saturated fats are reduced to less than 7 percent of total calories, and cholesterol levels to less than 200 mg/day. All of the other nutrients are the same as in Step I.
- Protein should be derived from plant sources and lean sources of animal protein.
- Complex carbohydrates from different vegetables, fruits, and whole grains are good sources of vitamins, minerals, and fiber. A diet rich in soluble fiber, including oat bran, legumes, barley, and most fruits and vegetables may be effective in reducing blood cholesterol levels. A diet high in all types of fiber may also aid in weight management by promoting satiety at lower levels of calorie and fat intake. Some authorities recommend 20 to 30 grams of fiber daily, with an upper limit of 35 grams. 546, 567, 568
- During weight loss, attention should be given to maintaining an adequate intake of vitamins and minerals. Maintenance of the recommended calcium intakes of 1,000 to 1,500 mg/day is especially important for women who may be at risk of osteoporosis. 569 dietary intervention provided. Most programs involved dietitians and nutritionists as primary therapists and used group therapy rather than individual sessions. The length of time spent during each session and the nature of the practitioner/ patient interaction tended not to be provided.
Evidence Statement: Physical activity contributes to weight loss, both alone and when it is combined with dietary therapy. Evidence Category A.
Rationale: Increased physical activity alone can create a caloric deficit and can contribute to weight loss. However, efforts to achieve weight loss through physical activity alone generally produce an average of a 2 to 3 percent decrease in body weight or BMI. Even so, increased physical activity is a useful adjunct to LCDs in promoting weight reduction.
Evidence Statement: Physical activity in overweight and obese adults increases cardiorespiratory fitness independent of weight loss. Evidence Category A.
Rationale: There is strong evidence that increased physical activity increases cardiorespiratory fitness, with or without weight loss. Improved cardiovascular fitness also improves the quality of life in overweight patients by improving mood, self-esteem, and physical function in daily activities.
Evidence Statement: Physical activity independently reduces CVD risk factors (Evidence Category A), and reduces risk for cardiovascular disease. Evidence Category C.
Rationale: There is considerable evidence that physical inactivity is an independent risk factor for CVD and diabetes. Furthermore, the more active an individual is, the lower the risk. By the same token, increased physical activity appears to independently reduce risk for CVD morbidity and mortality, and diabetes. Physical activity reduces elevated levels of CVD risk factors, including blood pressure and triglycerides, increases HDL-cholesterol, and improves glucose tolerance with or without weight loss.
Evidence Statement: Physical activity contributes to a decrease in body fat, including a modest effect on abdominal fat. Evidence Category B.
Rationale: Physical activity appears to have a favorable effect on distribution of body fat. Several large cross-sectional studies in Europe, Canada, and the United States showed an inverse association between energy expenditure through physical activity and several indicators of body fat distribution, such as WHR and waist-to-thigh circumference ratio. Fewer data are available on the effects of physical activity on waist circumference, although the ratio changes noted above suggest a decrease in abdominal obesity. Only a few randomized controlled trials that have tested the effect of physical activity on weight loss measured waist circumference. In some (but not all) studies, physical activity was found to produce only modest weight loss and decreased waist circumference. However, it is not known whether the effects of physical activity on abdominal fat are independent of weight loss.
Strategies to Increase Physical activity
Many people live sedentary lives, have little training or skills in physical activity, and are difficult to motivate toward increasing their activity. For these reasons, starting a physical activity regimen may require supervision for some people.
The need to avoid injury during physical activity is high. Extremely obese persons may need to start with simple exercises that can gradually be intensified. The practitioner must decide whether exercise testing for cardiopulmonary disease is needed before embarking on a new physical activity regimen. This decision should be based on a patient's age, symptoms, and concomitant risk factors.
For most obese patients, physical activity should be initiated slowly, and the intensity should be increased gradually. Initial activities may be walking or swimming at a slow pace. With time, depending on progress, the amount of weight lost, and functional capacity, the patient may engage in more strenuous activities. Some of these include fitness walking, cycling, rowing, cross-country skiing, aerobic dancing, and rope jumping. Jogging provides a high-intensity aerobic exercise, but can lead to orthopedic injury. If jogging is desired, the patient's ability to do this must first be assessed. The availability of a safe environment for the jogger is also a necessity. Competitive sports, such as tennis and volleyball, can provide an enjoyable form of physical activity for many, but again, care must be taken to avoid injury, especially in older people. As the examples listed in Table 5 show, a moderate amount of physical activity can be achieved in a variety of ways. People can select activities that they enjoy and that fit into their daily lives. Because amounts of activity are functions of duration, intensity, and frequency, the same amounts of activity can be obtained in longer sessions of moderately intense activities (such as brisk walking) as in shorter sessions of more strenuous activities (such as running).
A regimen of daily walking is an attractive form of physical activity for many people, particularly those who are overweight or obese. The patient can start by walking 10 minutes, 3 days a week, and can build to 30 to 45 minutes of more intense walking at least 5 days a week and preferably most, if not all, days.577, 578 With this regimen, an additional 100 to 200 calories per day of physical activity can be expended. Caloric expenditure will vary depending on the individual's body weight and intensity of the activity (see Table 6).
This regimen can be adapted to other forms of physical activity, but walking is particularly attractive because of its safety and accessibility.
| Table 5: Examples of Moderate Amounts of Activity* |
|---|
| Washing and waxing a car for 45-60 minutes |
Less Vigorous, More Time **
More Vigorous, Less Time |
| Washing windows or floors for 45-60 minutes |
| Playing volleyball for 45 minutes |
| Playing touch football for 30-45 minutes |
| Gardening for 30-45 minutes |
| Wheeling self in wheelchair for 30-40 minutes |
| Walking 1 ¾ miles in 35 minutes (20 min/mile) |
| Basketball (shooting baskets) for 30 minutes |
| Bicycling 5 miles in 30 minutes |
| Dancing fast (social) for 30 minutes |
| Pushing a stroller 1 ½ miles in 30 minutes |
| Raking leaves for 30 minutes |
| Walking 2 miles in 30 minutes (15 min/mile) |
| Water aerobics for 30 minutes |
| Swimming laps for 20 minutes |
| Wheelchair basketball for 20 minutes |
| Basketball (playing a game) for 15-20 minutes |
| Bicycling 4 miles in 15 minutes |
| Jumping rope for 15 minutes |
| Running 1 ½ miles in 15 minutes (10 min/mile) |
| Shoveling snow for 15 minutes |
| Stair walking for 15 minutes |
|
| * A moderate amount of physical activity is roughly equivalent to physical activity that uses approximately 150 calories of energy per day, or 1,000 calories per week. |
| ** Some activities can be performed at various intensities; the suggested durations correspond to expected intensity of effort. |
This regimen can be adapted to other forms of physical activity, but walking is particularly attractive because of its safety and accessibility. With time, a larger weekly volume of physical activity can be performed that would normally cause a greater weight loss if it were not compensated by a higher caloric intake.
Reducing sedentary time is another approach to increasing activity. Patients should be encouraged to build physical activities into each day. Examples include leaving public transportation one stop before the usual one, parking further than usual from work or shopping, and walking up stairs instead of taking elevators or escalators. New forms of physical activity should be suggested, e.g., gardening, walking a dog daily, or new athletic activities. Engaging in physical activity can be facilitated by identifying a safe area to perform the activity, e.g., community parks, gyms, pools, and health clubs. However, when these sites are not available, an area of the home can be identified and perhaps outfitted with equipment such as a stationary bicycle or a treadmill.
Health professionals should encourage patients to plan and schedule physical activity 1 week in advance, budget the time necessary to do it, and document their physical activity by keeping a diary and recording the duration and intensity of exercise.
Recommendation: Physical activity should be an integral part of weight loss therapy and weight maintenance. Evidence Category A. Initially, moderate levels of physical activity for 30 to 45 minutes, 3 to 5 days per week should be encouraged. All adults should set a long-term goal to accumulate at least 30 minutes or more of moderate-intensity physical activity on most, and preferably all, days of the week. Evidence Category B.
Behavior therapy
Behavioral strategies to reinforce changes in diet and physical activity can produce a weight loss in obese adults in the range of 10 percent of baseline weight over 4 months to 1 year. Unless a patient acquires a new set of eating and physical activity habits, long-term weight reduction is unlikely to succeed. The acquisition of new habits is particularly important for long-term weight maintenance at a lower weight. Most patients return to baseline weights in the absence of continued intervention. Thus, the physician or staff members must become familiar with techniques for modifying life habits of overweight or obese patients. The goal of behavior therapy is to alter the eating and activity habits of an obese patient. Techniques for behavior therapy have been developed to assist patients in modifying their life habits.
Evidence Statement: Behavior therapy, in combination with an energy deficit, provides additional benefits in assisting patients to lose weight short-term (1 year). Its effectiveness for long-term weight maintenance has not been shown in the absence of continued behavioral intervention. Evidence Category B.
Rationale: The primary assumptions of behavior therapy are that:
| by changing eating and physical activity habits, it is possible to change body weight; |
| patterns of eating and physical activity are learned behaviors and can be modified; and |
| to change these patterns over the long term, the environment must be changed. |
Behavior therapies provide methods for overcoming barriers to compliance with dietary therapy and/or increased physical activity, and are thus important components of weight loss therapy. Most weight loss programs incorporating behavioral strategies do so as a package that includes education about nutrition and physical activity. However, this standard "package" of management should not ignore the need for individualizing behavioral strategies.
Behavior therapy strategies used in weight loss and weight maintenance programs
Studies reviewed for this report examined a range of modalities of behavioral therapy. No single method or combination of behavioral methods proved to be clearly superior. Thus, various strategies can be used by the practitioner to modify patient behavior. The aim is to change eating and physical activities behaviors over the long term. Such change can be achieved either on an individual basis or in group settings. Group therapy has the advantage of lower cost. Specific behavioral strategies include the following:
| Self-monitoring of both eating habits and physical activity - Objectifying one's own behavior through observation and recording is a key step in behavior therapy. Patients should be taught to record the amount and types of food they eat, the caloric values, and nutrient composition. Keeping a record of the frequency, intensity, and type of physical activity likewise will add insight to personal behavior. Extending records to time, place, and feelings related to eating and physical activity will help to bring previously unrecognized behavior to light. |
| Stress management - Stress can trigger dysfunctional eating patterns, and stress management can defuse situations leading to overeating. Coping strategies, meditation, and relaxation techniques all have been successfully employed to reduce stress. |
| Stimulus control - Identifying stimuli that may encourage incidental eating enables individuals to limit their exposure to high-risk situations. Examples of stimulus control strategies include learning to shop carefully for healthy foods, keeping high-calorie foods out of the house, limiting the times and places of eating, and consciously avoiding situations in which overeating occurs. |
| Table 6: Duration of Various Activities to Expend 150 Kilocalories For an Average 70 KG (154 LB) Adult |
|---|
| Intensity | Activity | Approximate duration in minutes |
| Moderate | Volleyball, noncompetitive | 43 |
Moderate | Walking, moderate pace (3mph, 20 min/mile) | 37 |
Moderate | Walking, brisk pace (4mph, 15 min/mile) | 32 |
Moderate | Table tennis | 32 |
Moderate | Raking leaves | 32 |
Moderate | Social dancing | 29 |
Moderate | Lawn mowing (powered push mower) | 29 |
Hard | Jogging (5 mph, 12 min/mile) | 18 |
Hard | Field hockey | 16 |
Very Hard | Running (6 mph, 10 min/mile) | 13 |
|
| Source: Surgeon General's Report on Physical Activity and Health |
| Problem solving - This term refers to the self correction of problem areas related to eating and physical activity. Approaches to problem solving include identifying weight-related problems, generating or brainstorming possible solutions and choosing one, planning and implementing the healthier alternative, and evaluating the outcome of possible changes in behavior. Patients should be encouraged to reevaluate setbacks in behavior and to ask "What did I learn from this attempt?" rather than punishing themselves. |
| Contingency management - Behavior can be changed by use of rewards for specific actions, such as increasing time spent walking or reducing consumption of specific foods. Verbal as well as tangible rewards can be useful, particularly for adults. Rewards can come from either the professional team or from the patients themselves. For example, self-rewards can be monetary or social and should be encouraged. |
| Cognitive restructuring - Unrealistic goals and inaccurate beliefs about weight loss and body image need to be modified to help change self-defeating thoughts and feelings that undermine weight loss efforts. Rational responses designed to replace negative thoughts are encouraged. For example, the thought, "I blew my diet this morning by eating that doughnut; I may as well eat what I like for the rest of the day," could be replaced by a more adaptive thought, such as, "Well, I ate the doughnut this morning, but I can still eat in a healthy manner at lunch and dinner." |
| Social support - A strong system of social support can facilitate weight reduction. Family members, friends, or colleagues can assist an individual in maintaining motivation and providing positive reinforcement. Some patients may benefit by entering a weight reduction support group. Overweight patients should be asked about (possibly) overweight children and family weight control strategies. Parents and children should work together to engage in and maintain healthy dietary and physical activity habits. |
Treatment of Obese Individuals With Binge Eating Disorder
If a patient suffers from binge eating disorder (BED), consideration can be given to referring the patient to a health professional who specializes in BED treatment. Behavioral approaches to BED associated with obesity have been derived from cognitive behavior therapy (CBT) used to treat bulimia nervosa. Among the techniques are self-monitoring of eating patterns, encouraging regular patterns of eating (three meals a day plus planned snacks), cognitive restructuring, and relapse prevention strategies.
Recommendation: Behavior therapy strategies to promote diet and physical activity should be used routinely, as they are helpful in achieving weight loss and weight maintenance. Evidence Category B.
Combined therapy
To achieve the greatest likelihood of success from weight loss therapy, the combination of dietary therapy with an LCD, increased physical activity, and behavior therapy will be required. Inclusion of behavior therapy and increased physical activity in a weight loss regimen will provide the best opportunity for weight loss, and hopefully for long-term weight control. In order to achieve weight loss, such a regimen should be maintained for at least 6 months before considering pharmacotherapy.
Evidence Statement: Combined intervention of an LCD, increased physical activity, and behavior therapy provides the most successful therapy for weight loss and weight maintenance. Evidence Category A.
Rationale: Clinical trials have demonstrated that combining behavior therapy, LCDs, and increased physical activity provides better outcomes for long-term weight reduction than programs that use only one or two of these modalities. A lower-fat diet markedly improves the potential of physical activity to achieve a negative energy balance. In addition, lower-fat diets that are also low in saturated fats reduce serum cholesterol levels, which would reduce CVD risk. It is difficult to achieve a negative energy balance and weight loss with physical activity of moderate duration and intensity in individuals who consume a high-fat diet and alcohol.
Recommendation: Weight loss and weight maintenance therapy should employ the combination of LCDs, increased physical activity, and behavior therapy. Evidence Category A.
Pharmacotherapy
Drug therapy has undergone radical changes in the last 2 years. With the publication of the trials with phentermine and fenfluramine by Weintraub in 1992 (210 weeks), drug therapy began to change from short-term to long-term use. Both dexfenfluramine and fenfluramine alone, as well as the combination of phentermine/ fenfluramine, were used long term. However, concerns about recently reported unacceptable side effects, such as valvular lesions of the heart causing significant insufficiency of the valves, have led to the withdrawal of the drugs dexfenfluramine and fenfluramine from the market in September 1997. No drugs remained that were approved by the Food and Drug Administration (FDA) for use longer than 3 months. In November 1997, the FDA approved a new drug, sibutramine, for use in obesity and is in the process of evaluating or list at for long-term use.
Evidence Statement: Appropriate weight loss drugs can augment diet, physical activity, and behavior therapy in weight loss. Evidence Category B.
Rationale: The purpose of weight loss and weight maintenance is to reduce health risks. If weight is regained, health risks increase once more. The majority of persons who lose weight regain it, so the challenge to the patient and the practitioner is to maintain the weight loss. Because of the tendency to regain weight after weight loss, the use of long-term medication to aid in the treatment of obesity may be indicated in carefully selected patients.
The drugs used to promote weight loss have been anorexiants or appetite suppressants. Three classes of anorexiant drugs have been developed, all of which affect neurotransmitters in the brain: those that affect catecholamines, those that affect serotonin, and those that affect both. They work by increasing the secretion of dopamine, norepinephrine, or serotonin into the synaptic neural cleft, or by inhibiting the reuptake of these neurotransmitters back into the neuron, or by both mechanisms. The new agent sibutramine has norepinephrine and serotonin effects. Another new agent, orlistat, has a different mechanism of action, the blockage of fat absorption. Very few trials longer than 6 months have been done with any drug. The ones tested for at least 1 year that received FDA approval for long-term use are shown in Table 7.
These drugs are effective but modest in their ability to produce weight loss. Net weight loss attributable to drugs generally has been reported to be in the range of 2 to 10 kg (4.4 to 22 lb), although some patients lose significantly more weight. It is not possible to predict how much weight an individual may lose. Most of the weight loss usually occurs in the first 6 months of therapy.
Adverse effects include primary pulmonary hypertension with fenfluramine and dexfenfluramine, valvular heart disease with dexfenfluramine and fenfluramine, and increases in blood pressure and pulse with sibutramine. With orlistat, there is a possible decrease in the absorption of fat-soluble vitamins; overcoming this may require vitamin supplementation. People with a history of high blood pressure, CHD, congestive heart failure, arrhythmias, or history of stroke should not take sibutramine, and all patients taking the medication should have their blood pressure monitored on a regular basis. Depression has been described with the serotonergic drugs but it is generally not clinically significant. Neurotoxic effects with neuronal atrophy have been described with high doses of dexfenfluramine in rats and primates, but not in humans. The risks for using appetite suppressant drugs during pregnancy is unknown.
| Table 7: Weight Loss Drugs |
| Drug | Action | Adverse Effects |
| dexfenfluramine* | serotonin reuptake inhibitor | valvular heart disease |
| fenfluramine* neurotoxicity | serotonin releaser | primary pulmonary hypertension |
| sibutramine | norepinephrine, dopamine, and serotonin reuptake inhibitor | increase in heart rate and blood pressure |
| orlistat± | inhibits pancreatic lipase, decreases fat absorption | decrease in absorption of vitamins fat-soluble soft stools and anal leakage possible link to breast cancer |
| +Ephedrine and caffeine, and, fluoxetine have also been tested for weight loss, but are not approved for use in the treatment of obesity. Mazindol, phentermine, benzphetamine, and phendimetrazine are approved for only short-term use for the treatment of obesity. |
| FDA approval withdrawn |
| ± FDA approval pending |
|
Evidence Statement: Weight loss drugs approved by the FDA for long-term use may be useful as an adjunct to diet and physical activity for patients with a BMI of ³ 30 with no concomitant obesity-related risk factors or diseases, and for patients with a BMI of ³ 27 with concomitant obesity-related risk factors or diseases. Evidence Category B.
Rationale: If after at least 6 months on a weight loss regimen of an LCD, increased physical activity, and behavior therapy, the patient has not lost the recommended 1 lb/week, careful consideration may be given to pharmacotherapy. There are few long-term studies evaluating the safety or effectiveness of many currently approved weight loss medications. At present, sibutramine is available for long-term use. (Note: FDA approval for orlistat is pending a resolution of labeling issues and results of Phase III trials.) Their risk/benefit ratio is such that they can be recommended for use with the degree of obesity outlined above. Weight loss medications should be used only by patients who are at increased medical risk because of their weight and should not be used for "cosmetic" weight loss. The risk factors and diseases considered serious enough to warrant pharmacotherapy at BMI of 27 to 29.9 are hypertension, dyslipidemia, CHD, type 2 diabetes, and sleep apnea.
Not every patient responds to drug therapy. Tests with weight loss drugs have shown that initial responders tend to continue to respond, while initial nonresponders are less likely to respond even with an increase in dosage. If a patient does not lose 2 kg (4.4 lb) in the first 4 weeks after initiating therapy, the likelihood of long-term response is very low. This finding may be used as a guide to treatment, either continuing medication in the responders or stopping it in the nonresponders. If weight is lost in the initial 6 months of therapy or is maintained after the initial weight loss phase, this should be considered a success, and the drug may be continued. It is important to remember that the major role of medications should be to help patients stay on a diet and physical activity plan while losing weight. Medication cannot be expected to continue to be effective in weight loss or weight maintenance once it has been stopped. The use of the drug may be continued as long as it is effective and the adverse effects are manageable and not serious. There are no indications for specifying how long a weight loss drug should be continued. Therefore, an initial trial period of several weeks with a given drug or combination of drugs may help determine their efficacy in a given patient. If a patient does not respond to a drug with reasonable weight loss, the physician should reassess the patient to determine adherence to the medication regimen and adjunctive therapies, or consider the need for dosage adjustment. If the patient continues to be unresponsive to the medication, or serious adverse effects occur, the physician should consider its discontinuation.
Evidence Statement: Adverse side effects from the use of weight loss drugs have been observed in patients. Evidence Category A.
Rationale: The potential for side effects from the use of weight loss drugs is of great concern. Adverse effects with sibutramine include increased blood pressure and tachycardia. With orlistat there are oily and loose stools and some fat-soluble vitamin malabsorption. Thus, a multivitamin supplement is recommended. Side effects are generally mild and may improve with continued use, although their persistence may result in discontinuation of the drug.
There is a great interest in weight loss drugs among consumers. Because of the possibility of serious adverse effects, it is incumbent on the practitioner to use drug therapy with caution. Practitioners should be sure that patients are not taking drugs that have been withdrawn from the market for safety reasons, and herbal medications are not recommended as part of a weight loss program. These preparations have unpredictable amounts of active ingredients and unpredictable and potentially harmful effects. In those patients with a lower level of obesity risk,
non-pharmacological therapy is the treatment of choice. It is important for the physician to monitor both the effectiveness and the side effects of the drug.
Evidence Statement: Using weight loss drugs singly (not in combination) and starting with the lowest effective doses can decrease the likelihood of adverse effects. Evidence Category C.
Rationale: Given the fact that adverse events may increase in association with combination drug therapy, it seems wise that, until further safety data are available, using weight loss drugs singly would be more prudent. Some patients will respond to lower doses, so that full dosage is not always necessary. The short-term use of drugs (< 3 months) has not generally been found to be effective.
Drugs should be used only as part of a comprehensive program that includes behavior therapy, diet, and physical activity. Appropriate monitoring for side effects must be continued while drugs are part of the regimen. Patients will need to return for
follow up in 2 to 4 weeks, then monthly for 3 months, and then every 3 months for the first year after starting the medication. After the first year, the doctor will advise the patient on appropriate return visits. The purposes of these visits are to monitor weight, blood pressure, and pulse, discuss side effects, conduct laboratory tests, and answer questions.
Since obesity is a chronic disorder, the short-term use of drugs is not helpful. The health professional should include drugs only in the context of a long-term treatment strategy. The risk/benefit ratio cannot be predicted at this time, since not enough long-term data (> 1 year) are available on any of the available drugs.
Recommendation: Weight loss drugs approved by the FDA may only be used as part of a comprehensive weight loss program, including dietary therapy and physical activity, for patients with a BMI of ³ 30 with no concomitant obesity-related risk factors or diseases, and for patients with a BMI of ³ 27 with concomitant obesity-related risk factors or diseases. Weight loss drugs should never be used without concomitant lifestyle modifications. Continual assessment of drug therapy for efficacy and safety is necessary. If the drug is efficacious in helping the patient lose and/or maintain weight loss and there are no serious adverse effects, it can be continued. If not, it should be discontinued. Evidence Category B.
Surgery for weight Loss
Surgery is one option for weight reduction for some patients with severe and resistant obesity. The aim of surgery is to modify the gastrointestinal tract to reduce net food intake. Most authorities agree that weight loss surgery should be reserved for patients with severe obesity, in whom efforts at other therapy have failed, and who are suffering from the complications of obesity. Considerable progress has been made in developing safer and more effective surgical procedures for promoting weight loss. Surgical interventions commonly used include gastroplasty, gastric partitioning, and gastric bypass. These procedures are designed primarily to reduce food consumption. They have replaced previous procedures that were designed to promote malabsorption of nutrients. The latter procedures were fraught with side effects that made their use impractical or dangerous.
Evidence Statement: Gastrointestinal surgery (gastric restriction [vertical gastric banding] or gastric bypass [Roux-en Y]) can result in substantial weight loss, and therefore is an available weight loss option for well-informed and motivated patients with a BMI ³ 40 or ³ 35, who have comorbid conditions and acceptable operative risks. Evidence Category B.
Rationale: According to the National Institutes of Health's Consensus Development Conference on Gastrointestinal Surgery for Severe Obesity, the risk for morbidity and mortality accompanying obesity increases with the degree of overweight. Thus, treatment of clinically severe obesity involves an effort to create a caloric deficit sufficient to result in weight loss and reduction of weight-associated risk factors or comorbidities. Surgical approaches can result in substantial weight loss, i.e., from 50 kg (110 lb) to as much as 100 kg (220 lb) over a period of 6 months to 1 year. A major limitation of nonsurgical approaches is the failure to maintain reduced body weight in many individuals.
Surgical procedures in current use (gastric restriction [vertical gastric banding] and gastric bypass [Roux-en Y]) can induce substantial weight loss, and serve to reduce weight-associated risk factors and comorbidities. Compared to other interventions available, surgery has produced the longest period of sustained weight loss. Assessing both perioperative risk and longterm complications is important and requires assessing the risk/benefit ratio in each case. Patients whose BMI equals or exceeds 40 kg/mare potential candidates for surgery if they strongly desire substantial weight loss, because obesity severely impairs the quality of their lives. Less severe obese patients (BMIs between 35 and 39.9 kg/m) also may be considered for surgery. This group primarily includes those patients with high-risk comorbid conditions (cardiovascular, sleep apnea, uncontrolled type 2 diabetes) or weight-induced physical problems interfering with performance of daily life activities.
A recent retrospective study of severely overweight patients with noninsulin-dependent diabetes, who were referred for consideration of a gastric bypass procedure, allowed for a comparison of those who opted for the surgical procedure versus those who did not undergo the procedure because of personal preference or refusal of insurance payment. Patients undergoing the surgical procedure had a decrease in mortality rate for each year of follow up. This latter observation provides initial documentation of the significant impact that reduction in weight may have on mortality.
Most of the surgery studies primarily included women of childbearing age. Caution should be exercised in selecting candidates for surgery to treat obesity, as pregnancy demands increase nutritional needs and a normal need for weight gain. Women with reproductive potential should be advised to avoid pregnancy until their weight has stabilized postoperatively and potential micronutrient deficiencies have been identified and treated.
Of special note is that many of the studies reported to date have not had population samples representative of the general severely overweight population with respect to race, ethnicity, cultural or socioeconomic background, or gender.
Evidence Statement: Patients opting for surgical intervention should be followed by a multidisciplinary team (medical, behavioral, and nutritional). Evidence Category D.
Rationale: As for all other interventions for obesity, an integrated program should be in place that will provide guidance concerning the necessary dietary regimen, appropriate physical activity, and behavioral and social support both prior to and after the surgical procedure.
Evidence Statement: Lifelong medical surveillance after surgical therapy is a necessity. Evidence Category C.
Rationale: Since surgical procedures result in some loss of absorptive function, the long-term consequences of potential nutrient deficiencies must be recognized and adequate monitoring must be performed, particularly with regard to vitamin B, folate, and iron. Some patients may develop other gastrointestinal symptoms such as "dumping syndrome" or gallstones. Occasionally, patients may have postoperative mood changes or their presurgical depression symptoms may not be improved by the achieved weight loss. Thus, surveillance should include monitoring of indices of inadequate nutrition and modification of any preoperative disorders. Table 8 illustrates some of the complications that can occur following gastric bypass surgery.
| Table 8: Gastric Bypass Surgery Complications: 14-Year Follow Up |
| Vitamin B12 deficiency | 239 | 39.9 percent |
| Readmit for various reasons | 229 | 38.2 percent |
| Incisional hernia | 143 | 23.9 percent |
| Depression | 142 | 23.7 percent |
| Staple line failure | 90 | 15.0 percent |
| Gastritis | 79 | 13.2 percent |
| Cholecystitis | 68 | 11.4 percent |
| Anastomotic problems | 59 | 9.8 percent |
| Dehydration, malnutrition | 35 | 5.8 percent |
| Dilated pouch | 19 | 3.2 percent |
| Data derived from source (Pories WJ595) and modified based on personal communication. |
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Recommendation: Weight loss surgery is an option for carefully selected patients with clinically severe obesity (BMI ³ 40 or ³ 35 with comorbid conditions) when less invasive methods of weight loss have failed and the patient is at high risk for obesity-associated morbidity or mortality. Evidence Category B.
Standard obesity treatment approaches should be tailored to the needs of patients. It is, however, difficult to determine from the literature how often this occurs and whether it makes weight loss programs more effective. Very few published reports of such adapted programs can be identified, particularly when a distinction is made from reports that include or focus on special populations but do not report any particular steps taken to modify the intervention for these populations. In addition, it is impossible to compare directly the amount of weight lost using specially adapted programs with that achieved when more standard approaches are used. Studies reporting these programs are sometimes pilot studies or descriptive reports that do not meet the standards of evidence set forth elsewhere in these guidelines. Where randomized controlled trials or quasi-experiments are available, they usually do not include an internal comparison with a program involving no adaptations. Appendix III illustrates the types of adaptations that have been reported.
Large individual variation exists within any social or cultural group; furthermore, there is substantial overlap among subcultures within the larger society. There is, therefore, no "cookbook" or standardized set of rules to optimize weight reduction with a given type of patient. A theoretical and qualitative analysis of cultural appropriateness in obesity treatment programs has been conducted, and it provides some guidance for incorporating patient characteristics and perspectives when designing and delivering weight loss programs. Some examples follow:
| Adapt the setting and staffing to the patient population. The setting should:
 | be physically accessible to the patient; |
| have features likely to be familiar to the patient; |
| be free of negative psychosocial connotations; |
| be devoid of aspects that create a large social distance among patients or between patient and practitioner; and |
| promote active patient participation and high patient self-esteem and self-efficacy. |
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The staff should be culturally self-aware and culturally competent in working with persons of diverse cultural backgrounds and income or educational levels. For example, cultural adaptation of programs has been approached with the assumption that community centers may be preferable to hospitals or medical offices as venues for conducting lifestyle weight reduction programs. Or, some programs have included peer educators as a possible way of helping to overcome background and social class differences by providing a bridge of knowledge, experience, and perspective between patients and practitioners.
| List assumptions about the type of patient for whom the program will be best suited and evaluate the extent to which these assumptions are appropriate for prospective patients. Where appropriate, modify the program to avoid the need for certain assumptions. Consider patients
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| Consider how the obesity treatment program fits in other aspects of the health care and self care of the patient(s), and integrate other aspects where appropriate. For example, for those patients with diabetes, information about weight reduction should be aligned with other diabetes management advice. |
| Expect and allow for program modifications based on patient feedback and preferences. Program appropriateness can be increased when patients can express their needs and preferences, and the program is then adapted to those needs and preferences. This is especially applicable when practitioners have limited common experience with patients. |
In recent years, a fat acceptance, non-dieting advocacy group has developed. This has emerged from concerns about weight cycling and its possible adverse effects on morbidity and mortality. However, recent evidence suggests that intentional weight loss is not associated with increased morbidity and mortality. For this reason, the guidelines have been made explicit on the importance of intervention for weight loss and maintenance in the appropriate patient groups.
Are the indications for treating obesity in older adults the same as those for younger adults?
| Does weight loss reduce risk factors in older adults? |
| Does weight reduction prolong the lives of older adults? |
| Are there risks associated with obesity treatment that are unique to older adults? |
The higher prevalence of cardiovascular risk factors in overweight versus non
overweight
persons is clearly observed at older ages. In addition, obesity is a major predictor of
functional limitations and mobility impairments in older adults. Both observational data and
applicable randomized controlled trials cited in these guidelines suggest that weight loss reduces
risk factors and improves functional status in older persons in the same manner as in
younger adults.
The question of whether weight reduction leads to increased survival among older
adults has been raised because of observations that weight reduction after age 60 or 65 years may
be unable to reverse the deleterious effects of longstanding obesity. Also, weight loss at older
ages has been associated with increased mortality. Some of the association of weight loss
with higher mortality may be due to the increased frequency at older ages of involuntary weight
loss due to identified or occult illness. In any case, the association of weight loss with higher
mortality applies most clearly to individuals who enter old age with a BMI in the lower part of
the range. It is not clear that it applies to overweight older persons with CVD risk factors.
This issue has been difficult to clarify in observational data, but there are no randomized trials
in which the effects of obesity treatment on mortality can be directly assessed, at any age.
The wisdom or importance of treating obesity at older ages has also been
questioned because of epidemiological observations suggesting a decreased significance of
obesity-related relative risks at older ages. However, these relative risk data are not a useful
reference point for considering whether obese older persons will benefit.
Relative risks are influenced by the characteristics of the comparison group. In this
case, the comparison group is lower-weight older persons who have also had high morbidity
and mortality.
Concerns about potential adverse effects of obesity treatment in older adults have been raised with respect to bone health and to dietary adequacy. Weight reduction may
accelerate aging-related bone loss and thereby increase the risk of osteoporotic fractures in
high-risk groups such as older white women. This concern is more relevant to weight loss in
thin persons than in obese persons. Some evidence suggests that including resistance training
and moderate weight-bearing exercise as a part of a weight reduction program may help
maintain bone integrity.
The general nutritional safety of weight reduction at older ages is of interest
because restrictions on overall food intake due to dieting could result in inadequate intakes of
protein or essential vitamins and minerals. In addition, involuntary weight loss indicative of
occult disease might be mistaken for success in voluntary weight reduction. These concerns can
be alleviated by providing proper nutritional counseling and regular body weight monitoring
for older persons for whom weight reduction is prescribed.
Evidence Statement: Age alone should not preclude treatment for obesity in adult men
and women. Evidence Category D.
Rationale: There is little evidence at present to indicate that obesity treatment should
be withheld from adult men and women on the basis of age alone up to 80 years of age.
Recommendation: A clinical decision to forego obesity treatment in an older adult should
be guided by an evaluation of the potential benefits of weight reduction for day-to-day functioning
and reduction of the risk of future cardiovascular events, as well as the patient's motivation for
weight reduction. Care must be taken to ensure that any weight reduction program minimizes
the likelihood of adverse effects on bone health or other aspects of nutritional status. Evidence
Category D.
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