Weight loss, cardiovascular risk factors, and quality of life after gastric bypass and duodenal switch: A study by Schiavon et al indicated that bariatric surgery can lead to a reduction in the number of antihypertensive drugs required by persons with obesity taking multiple blood pressure agents and in some cases can eliminate the need for any such medications. Melanocortin-4 receptor mutations are a frequent and heterogeneous cause of morbid obesity. But grapefruit juice doesn't have any proven "fat-burning" properties -- it may just have helped people feel full. A healthy sleep pattern is therefore important to harness weight loss benefits from other interventions.
Patient Screening, Assessment, and Expectations
Achieving a caloric deficit is still the most important component in achieving sustained weight loss. However, the considerable variance in individual energy expenditures and compliance with calorie-deficient plans make it difficult to reliably predict how much weight an individual will lose. Therefore, weight loss tends to reduce energy expenditure, dampening the effect of caloric deficits.
Because of their lowered energy expenditure, older subjects have increased difficulty in achieving sustained weight loss. The estimated reduction in energy expenditure is kcal per decade after the age of 30 years. Presumably because of their greater lean mass proportions, men tend to lose more weight than women do when caloric deficits are similar. In addition, some researchers have recommended using correction factors for estimating energy expenditure in obese patients.
All subjects underwent resting energy expenditure REE testing with indirect calorimetry and subjects also performed a symptom-limited bicycle cardiopulmonary exercise test to determine maximal achievable METs. Mean REE was 2. During the bicycle test, women performed 4. After the correction factors were applied, MET-peak increased to 6. Conventional diets can be broadly classified into 2 categories: The latter include the following:.
Although these diets are useful for short-term weight loss, none of them alone is associated with reliable, sustained weight loss.
The basic premise for people on these diets involves obtaining their detailed dietary inventory and using it to estimate their mean daily caloric intake. A reasonable goal for the caloric deficit is based on the new goal for total daily calories. Meal plans are then devised to provide this total, divided among 3 or more meals throughout the day. The meals may be based on regular, everyday foods.
In such cases, strategies for effective reduction of portion sizes become central. Alternatively, portion control can be achieved by participation in structured weight loss programs eg, Jenny Craig, Nutrisystem or by the purchase of products such as meal-replacement shakes, bars, prepackaged meals, and frozen entrees eg, Slim-Fast, Glucerna, Lean Cuisine, Healthy Choice, Smart Ones. These have adequate amounts of the major macronutrients based on the food pyramid from the US Department of Agriculture and recommended daily allowances RDAs.
These sources also have adequate micronutrients and trace elements. Alcohol, sodas, most fruit juices, and highly concentrated sweets are generally calorie dense and nutrient deficient so-called empty calories.
Consequently, these are generally prohibited or reduced to a minimum. These diets are associated with a mean weight loss of 0. With any low-calorie diet, maintaining an intake of protein with a high biologic value of Low-carbohydrate diets have become popular in the past few decades, with the Atkins diet being the most popular.
No robust data about the safety or long-term effectiveness of this diet are available. The premise of the diet is that caloric intake as protein is less prone to fat storage than is the equivalent caloric intake as carbohydrate; however, no physiologic data support this premise. Data on the long-term effects of a high-protein diet in rodents cause concern. They indicate that these diets may be associated with a reduced life span and a predisposition to neoplasia.
In 2 randomized trials, weight loss with Atkins-type diets was compared with conventional low-fat or balanced calorie-deficit diets. The South Beach diet is another low-carbohydrate diet. This program is more liberal in its carbohydrate allowance than the Atkins diet. In addition, the South Beach diet distinguishes between what are considered to be good and bad carbohydrates on the basis of their glycemic index.
Although the relevance and importance of the glycemic index is controversial, the diet encourages increased fiber intake, which is associated with lowered weight even when total caloric intake is relatively unchanged. Low glycemic index diets are better at helping to maintain weight loss than diets with a higher glycemic index; the same is true of diets with modestly increased protein intake, versus standard protein intake.
Persons who decide to use a low-carbohydrate diet should choose heart-healthy sources of fat, including monounsaturated fats, polyunsaturated fats, and fats rich in omega 3 fatty acids, rather than saturated fat. Protein sources should be fish, nuts, legumes, and lean poultry rather than pork chops, steak, and mutton.
Dansinger and colleagues compared the Zone, Ornish, and Atkins diets to each other and to a typical balanced, calorie-restricted Weight Watchers diet and found them all to have a similar impact on weight. At 1 year, the researchers observed no significant differences in weight loss among the 4 diets. Compliance and caloric deficits were more important predictors of weight loss and improvement in cardiovascular risk surrogates than was specific dietary composition.
A 2-year study found low-carbohydrate and low-fat diets to be equally efficacious in inducing weight loss. However, the study also found that a low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors. Very—low-calorie diets VLCDs are best used in an established, comprehensive program. When used in optimal settings, they can achieve a weight loss of 1. VLCDs are associated with profound initial weight loss, much of which is from loss of lean mass in the first few weeks.
However, this loss rapidly ceases, and weight-loss velocity then flattens. Such rapid weight loss is frequently followed with weight regain due to reduction in basal energy expenditure secondary to the loss of fat free mass.
Use special caution whenever VLCDs are prescribed to children, adolescents, or elderly patients. Use of VLCDs is contraindicated in the following settings:. Although VLCDs are associated with notable short-term weight loss and improved blood pressure and glycemic control, they cannot be sustained for longer than months.
Compliance beyond a few weeks is poor, and close supervision is required to avoid mishaps. Among the major complications to monitor are hair loss, skin thinning, hypothermia, cholelithiasis, and electrolyte derangement. Preoperative VLCDs have been postulated to decrease surgical risk by enhancing visualization during laparoscopic bariatric surgery. In a multicenter, randomized, controlled trial involving morbidly obese patients who underwent gastric bypass surgery, van Nieuwenhove et al reported a significantly lower rate of intraoperative complications among those who had undergone a day VLCD before the procedure.
There were, however, no significant differences in operative time or intraoperative complications between the control and VLCD groups. Dennis et al found that in overweight and obese middle-aged and older adults on a hypocaloric diet, drinking water before each main meal aided weight loss.
Water drinking could assist weight loss in overweight children. This is achieved primarily through a water-induced increase in resting energy expenditure. Before prescribing an intensive exercise program, clinicians should screen patients for cardiovascular and respiratory adequacy. Any clinically significant anomalies found require full evaluation by appropriate specialist physicians, and only after these issues have been adequately managed and stabilized should the patient begin an active exercise program.
Aerobic isotonic exercise is of the greatest value for persons who are obese. The ultimate minimum goal should be to achieve minutes of continuous aerobic exercise times per week. Anaerobic isometric exercise, including resistance training, can be cautiously added as an adjunct after the aerobic goal described above is achieved.
Resistance training is valuable in minimizing muscle mass loss and is particularly beneficial in patients with diabetes, as it increases glucose uptake by muscles. Exercise also increases metabolic activity and reduces body fat. Although most patients may be unable to sustain enough regular exercise to achieve weight loss, consistent, moderate exercise is important in maintaining weight and in improving overall cardiorespiratory fitness.
A study by Goodpaster et al showed that patients with severe obesity who introduced exercise concurrently with or after dietary intervention had significant weight loss and modification of cardiometabolic risk factors.
A study by Rejeski et al indicated that community weight-loss and physical activity programs can have a positive impact on mobility in elderly people who are overweight or obese and are in poor cardiovascular health. Behavioral modification for weight loss addresses learned behaviors that contribute to excessive food intake, poor dietary choices or habits, and sedentary activity habits.
Although this approach can yield improved results, it is inherently challenging and time-consuming. A trained professional must then have an in-depth discussion with the patient to develop an individualized plan to change these practices.
The effectiveness of this modality depends on a highly motivated patient and a dedicated counselor who is willing to maintain long-term follow-up. A sufficient amount of sleep favorably impacts the maintenance of fat-free mass during times of decreased energy intake. In contrast, insufficient sleep undermines the body's ability to limit expansion of fat mass. A healthy sleep pattern is therefore important to harness weight loss benefits from other interventions.
Treatment of obstructive sleep apnea, if present, also helps in weight reduction. Few medications are available for the treatment of obesity. All are indicated as adjuncts to caloric restriction, increased physical activity, and behavior modification.
Response to therapy should be evaluated by week The FDA has issued a consumer alert about over-the-counter weight-loss pills that contain undeclared, active pharmaceutical ingredients.
Orlistat blocks the action of pancreatic lipase, reducing triglyceride digestion and, thus, absorption. The drug may reduce absorption of some fat-soluble vitamins A, D, E, K and beta-carotene, as well as absorption of some medications. Lorcaserin is thought to decrease food consumption and promote satiety by selectively activating 5-HT2C receptors on anorexigenic pro-opiomelanocortin neurons in the hypothalamus.
Required postmarketing studies of lorcaserin will include a long-term trial to assess the risk for major adverse cardiac events. Lorcaserin should be used with caution in patients with heart failure, and it has not been studied in patients with serious valvular heart disease.
Liraglutide is a glucagonlike peptide-1 GLP-1 analog. GLP-1 is a physiological regulator of appetite and calorie intake, and the GLP-1 receptor is present in several areas of the brain involved in appetite regulation.
The dose for obesity differs from that of liraglutide Victoza that is used to treat diabetes. Saxenda is initiated at 0. Approval was based on data from 3 clinical trials that included about obese and overweight patients with and without significant weight-related conditions. Results from a clinical trial that enrolled patients without diabetes or with diabetes showed that patients had an average weight loss of 4. The amount of weight loss appears to be greater with higher baseline weights.
The exact mechanism of this effect is being actively investigated. Although the degree of efficacy is exciting, the propensity for adverse effects, especially CNS effects such as drowsiness, paresthesias, memory loss, and confusion, is cause for concern. In addition, the dose of topiramate in this product 46 mg, although a mg dose form is available for select patients is lower than those used for seizure management usually mg twice daily.
Bupropion increases dopamine activity in the brain, which appears to lead to a reduction in appetite and increase in energy expenditure by increasing activity of POMC neurons. Four agents are available in the United States for short-term weeks treatment of obesity: Several medications that are approved for other indications but that may also promote weight loss have been used off-label for obesity.
These include several antidepressants, such as selective serotonin reuptake inhibitors SSRIs. Medications used off-label for obesity include the following:. Methylphenidate - Not approved by the FDA for obesity management, but several anecdotal reports have described it as having variable success for this purpose [ ]. Octreotide - Lustig and colleagues reported the potential utility of octreotide in ameliorating the distinct subclass of hypothalamic obesity [ ].
Metformin does not have an indication for obesity, but it is useful in preventing diabetes and improving insulin resistance in conditions such as polycystic ovary syndrome. Its use was associated with weight neutrality or mild weight loss. The first glucagonlike peptide GLP -1 analogue, exenatide Byetta , although not FDA approved for obesity management, has been associated with modest weight loss in subjects with type 2 diabetes.
A similar effect was seen with liraglutide Victoza and long-acting exenatide Bydureon , which also are not approved by the FDA for obesity management. Higher liraglutide doses of 2. Some of these medications have been used as adjuncts in the medical management of obesity, with variable success. A meta-analysis of antidepressants and body weight found that fluoxetine was associated with some weight loss, although this effect appeared to be limited to the acute phase of treatment.
Bupropion is licensed for use as an antidepressant and for use in smoking cessation. It is associated with minimal to moderate weight loss in obese patients.
Ephedrine and caffeine are second-line options in the medical management of obesity. They both act by increasing energy expenditure, but they are associated with the potential for tachycardia, hypertension, and palpitations. These medications are associated with greater weight loss when used in combination than when used alone. Currently, the evidence for the efficacy of these 2 drugs in promoting weight loss is inconclusive. Neither substance has an FDA-approved indication for the treatment of obesity.
The central cannabinoid system has an increasingly recognized role in appetite and feeding disorders. CB1-receptor antagonists showed great potential for weight management in several human trials. Adverse effects, which were most prevalent at high doses, included dizziness, depression and suicidal ideation, headaches, nausea, vomiting, and diarrhea.
The drug was rejected by the FDA because of side effects of depression and suicidal ideation; in Europe, it was approved but later recalled. A Japanese study found evidence that beverages containing high amounts of catechin, a flavonoid found in green tea, may aid in preventing obesity.
By the 12th week, participants receiving the higher catechin dose had undergone a significantly greater reduction in waist circumference than did patients receiving the lower dose. The increasing knowledge that has come on the heels of the discovery of leptin by Friedman and colleagues in has spurred a whirlwind of research that has identified several potential pharmaceuticals. However, safety standards for obesity medications are necessarily high. Tolerance for adverse effects is limited; most persons who are obese are fairly healthy in the short term, but the risk for adverse drug effects is enhanced because patients must take antiobesity medications for extended periods possibly for the rest of their lives.
Agents in early phases of investigation that may yet prove useful against obesity include the following:. In addition, various nutraceuticals and herbal products have shown promise. For example, an extract from the African cactus Hoodia gordonii may cause clinically significant appetite suppression. The diabetes drug pramlintide Symlin , which is a synthetic analogue of the pancreatic hormone amylin, does not have an FDA indication for obesity management.
However, this drug is clearly associated with variable weight loss in people with type 1 or 2 diabetes, while improving overall glycemic control. Higher doses mcg before main meals than those approved for the management of type 2 diabetes mcg before main meals have produced modest weight loss in obese or overweight patients with and without diabetes.
Peptide YY is being developed as a nasal inhaler. Ongoing, preliminary phase 1 and 2 trials yielded encouraging results. Leptin is still used in cases of the rare obesity subclass of leptin-deficient obesity and lipodystrophy, but a study of the leptin analogue metreleptin in obese patients with diabetes found that metreleptin did not alter body weight. Preliminary reports suggest the potential utility of agents that impede dietary carbohydrate absorption.
Tagatose is one of the compounds in this class that is undergoing trials. The history of obesity medications is replete with disasters that have taught caution in the use of this group of medicines. For example, among the initial medications used for obesity management were amphetamine, methamphetamine, and phenmetrazine.
These were all withdrawn because of their high potential for abuse. However, fenfluramine was withdrawn in along with D-fenfluramine because of the potential for adverse cardiac, valvular, and pulmonary hypertensive effects in patients taking this drug. Other former antiobesity medications, and the reasons for their abandonment, include the following:. Rainbow pills a mixture of digitalis and diuretics - Fatal arrhythmias and electrolyte derangements. Some agents that initially showed promise were later demonstrated to be poor prospects in rigorous randomized intervention trials.
These include the following:. One strategy to prevent obesity that is being explored in the dietary industry involves the use of fat substitutes. Olestra Olean has been approved for use as a dietary supplement and additive in various foods, such as potato chips and crackers. Olestra consists of a sucrose polyester backbone with fatty-acid side chains; this structure makes the molecule too large for digestive enzymes of the gut to hydrolyze.
In many trials, olestra had fairly good tolerability, although foods containing it are apparently less tasty than foods cooked in regular fat. The major adverse effects reported were flatulence, bloating, diarrhea, and loose stools. Because of concerns regarding the possible malabsorption of fat-soluble vitamins, the FDA requires all olestra-prepared foods to be supplemented with these vitamins. Benecol contains stanols, predominantly sitostanol and campestan; Take Control is made up of sterols, primarily beta-sitosterol and campesterol.
Weight-loss benefits have not been demonstrated. Surgical therapy for obesity bariatric surgery is the only available therapeutic modality associated with clinically significant and relatively sustained weight loss in subjects with morbid obesity associated with comorbidities. Evidence shows that well-performed bariatric surgery, in carefully selected patients and with a good multidisciplinary support team, substantially ameliorates the morbidities associated with severe obesity.
Although bariatric surgery is the only therapeutic method associated with significant and rapid weight loss, it is expensive, highly procedure and surgeon specific, and certainly not the solution for the burgeoning obesity epidemic. Patient selection for bariatric procedures must be addressed along the same stringent lines as those discussed earlier for the selection of patients for medical weight-management programs.
Comorbidities that have been reported to be improved, ameliorated, or resolved through bariatric surgery include the following:. Other reports suggest improved quality of life and fertility after bariatric surgery. Although other outcomes are difficult to demonstrate and are awaiting clear documentation, these procedures may substantially reduce macrovascular complications eg, myocardial infarction , stroke, amputations, obesity-related malignancies, and a predisposition to infection, hernias, and varicose veins.
Although most bariatric procedures were initially developed in the setting of laparotomies, they now are increasingly performed laparoscopically, with reduced postoperative morbidity.
The laparoscopic approach to bariatric surgery is particularly well developed in Europe. Available data on the effectiveness of many of these procedures are still relatively scant. However, reports and meta-analyses from large numbers of patients on the most commonly performed procedures gastric restriction and gastric bypass lend veracity to the long-term effectiveness of bariatric surgery. Guidelines from the American Association of Clinical Endocrinologists, The Obesity Society, and the American Society for Metabolic and Bariatric Surgery endorse sleeve gastrectomy as an effective alternative to gastric banding, gastric bypass, and other types of bariatric surgery, saying that the procedure has advanced beyond the investigational stage.
However, the guidelines do not recommend any bariatric procedure as preferable over the others for patients with severe obesity. Flickinger and associates, in an examination of patients who received a Roux-en-Y gastric bypass, recorded a mean weight loss of 51 kg in 18 months, which was then maintained over 36 months of follow-up.
Roux-en-Y and other gastric-bypass procedures generally result in more weight loss than do gastric-restriction procedures. According to a study by Plecka et al, in patients who are morbidly obese, gastric bypass but not restrictive surgery apparently reduces the risk levels for the development of type 2 diabetes and myocardial infarction to those for the general population. However, the mortality risk in these patients nonetheless remains higher than that in the general population.
Improvement in glucose control was unrelated to baseline BMI or overall weight loss. A Norwegian study compared gastric bypass with duodenal switch and determined that duodenal switch surgery was associated with greater weight loss and greater reductions in total and LDL-C levels.
However, duodenal switch surgery was also associated with reductions in concentrations of vitamin A and hydroxyvitamin D, as well as with increased adverse effects. Similarly, a randomized trial from Sweden found greater postoperative weight loss in patients who had duodenal switch surgery than in those who had gastric bypass.
Fasting glucose and HgA1c were also lower at 3 years in the duodenal switch group. A study by Schiavon et al indicated that bariatric surgery can lead to a reduction in the number of antihypertensive drugs required by persons with obesity taking multiple blood pressure agents and in some cases can eliminate the need for any such medications.
The investigators found that Emerging data suggest that gastric pacing achieved by using implantable electrodes may have significant weight-loss effects. This outcome was initially discovered with the use of gastric pacemaker devices for gastroparesis in patients with diabetes.
Other adjunctive procedures that may be performed but that have an unclear utility include visceral fat removal, omentectomy, subcutaneous fat panniculectomy, and large-volume subcutaneous fat liposuction. Klein and colleagues indicated that liposuction in itself has no utility in improving cardiac risk factors among patients with obesity.
Some procedures, such as jaw wiring and insertion of a gastric balloon or a gastric wrap, are no longer popular because of their poor results compared with those of newer procedures and because of their high complication rates. Vagotomy has also declined in popularity, as the weight lost is typically regained within a few years. The mortality rate associated with standard bariatric surgical procedures in an experienced center should not exceed 1.
The surgical mortality rate is less than 0. In addition, gastric-specific operations can be associated with persistent vomiting and metabolic alkalosis. These operations are also more commonly associated with weight-loss failure and inadvertent splenectomy than are other surgical methods. Malabsorptive procedures gastric bypass can lead to deficiency of thiamine, iron, vitamin D, and vitamin B Prevalences for adverse events with gastric resection procedures with or without bypass are approximately as follows [ ]:.
Patients who receive bypass procedures are particularly prone to micronutrient deficiency states, especially of calcium, vitamin B, folate, and iron, as well as protein malnutrition. Rare cases of postural hypotension and severe hypoglycemia from nesidioblastosis have been reported. Life-threatening hypoglycemia usually requires partial or total pancreatectomy, while severe postural hypotension that cannot be corrected with fludrocortisone and midodrine requires reversal of the surgery. The following are among the major specific complications associated with malabsorptive operations:.
Failure rates based on weight loss are controversial. The overall failure rates for malabsorptive procedures are relatively low, although the need for reversal of the surgery because of resulting adverse effects appears to be relatively high. Despite the morbidity and mortality risk associated with bariatric surgery, the few reports involving follow-up on patients undergoing these procedures suggest overall improvement in quality of life.
Even more convincing than this finding is that most subjects who undergo these procedures, despite their postoperative complications and difficulties, indicate that they would undergo the procedures again if necessary. Inpatient evaluations of obese patients are important in the immediate postoperative period after antiobesity surgery. In addition, hospitalization may be required for the management of major complications, such as clinically significant respiratory or cardiac compromise.
Weight-management programs may be based in an outpatient or inpatient setting. No rigorous evidence suggests that inpatient programs are necessarily superior to outpatient programs of similar structure and content, however. Inpatient programs may offer the convenience of easy access to patients and ease of monitoring, but they are not only expensive to run and difficult to reimburse, they also generally cause considerable disruption to the patients' regular routine.
In addition, they offer little guarantee of sustained effect. Because of the sheer prevalence of obesity and the anticipated worsening of the pandemic in the next few decades, prevention is by far the most desirable means to curb the medical and economic consequences of this condition. However, few trials have addressed this issue, and those performed thus far have had mixed results. Given the global proportions of obesity, a concerted approach is needed to address the problem and should involve the development of a massive public health education program aimed at adults and children as a means of changing their eating, activity, and behavioral habits.
Cooperative efforts will also be needed among public health authorities, caterers, the fast food industry, and organizers of sports and outdoor games. Results of some public health education initiatives in Singapore and parts of China that are only now being evaluated suggest, as hoped, that such programs have the potential for reducing the incidence and prevalence of obesity and may also have an impact on the major comorbidities of obesity, such as type 2 diabetes and hypertension.
Until advances in gene therapy permit the alteration of genes that predispose to obesity, such programs are the only preventive options available. In select cases, consultation with a psychiatrist may be indicated. Psychiatric consultation should be sought for patients with psychiatric disorders and personality disorders eg, severe depression, mania, obsessive disorders that may be worsened by attempts at weight loss if not adequately treated and controlled.
As with the management of other chronic medical conditions eg, diabetes mellitus, hypertension, bronchial asthma , long-term success in the management of obesity is contingent on long-standing follow-up with the weight-loss program. Experience obtained from the lifestyle intervention group of patients in the Diabetes Prevention Program and information drawn from the ongoing Diabetes Prevention Program Observation study have borne out the importance of regular follow-up.
Patient visits may not need to occur as frequently during follow-up as during the initial weight-loss phase. Nevertheless, they are paramount if the lessons learned regarding diet, exercise habits, and behavioral patterns are to be maintained. Obesity in the Early Childhood Years: State of the Science and Implementation of Promising Solutions: Prevalence of obesity and trends in the distribution of body mass index among US adults, Comorbidities of obesity in school children: Prevalence of self-reported clinically diagnosed sleep apnea according to obesity status in men and women: National Health and Nutrition Examination Survey, Body mass index, effect modifiers, and risk of pancreatic cancer: Adiposity and cancer at major anatomical sites: Association between obesity and health-related quality of life in patients with coronary artery disease.
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Many people who have the surgery lose weight quickly, but regain some weight later on. If you follow diet and exercise recommendations, you can keep most of the weight off. You will also need medical follow-up for the rest of your life. Weight Loss Surgery Also called: Bariatric surgery, Bypass surgery, Gastric banding, Obesity surgery.
On this page Basics Summary Start Here. Resources Find an Expert. Who Is It For? Sleeve Gastrectomy BroadcastMed - St. Gastric Bypass National Institutes of Health. A dissonance-based intervention for women post roux-en-Y gastric bypass surgery