Management of obesity
Management of obesity can include lifestyle changes, medications, or surgery. The main treatment for obesity consists of weight loss via dieting and physical exercise. Diet programs can produce weight loss over the short term and long-term, although combining with exercise and counseling provide greater results. Dietary and lifestyle changes are effective in limiting excessive weight gain in pregnancy and improve outcomes for both the mother and the child. The National Institutes of Health recommend a weight loss goal of 5% to 10% of the person's current weight over six months.
One medication, orlistat, is current widely available and approved for long term use. Weight loss is modest to important, with an average of at 1 to 4 years, but there is little information on how these drugs affect longer-term complications of obesity. Its use is associated with high rates of gastrointestinal side effects.
The most effective treatment for obesity is bariatric surgery. Surgery for severe obesity is associated with long-term weight loss and decreased overall mortality. One study found a weight loss of between 14% and 25% at 10 years, and a 29% reduction in all cause mortality when compared to standard weight loss measures.
A 2007 review concluded that certain subgroups such as those with type 2 diabetes and women show long term benefits in all cause mortality, while outcomes for men do not seem to be improved with weight loss. A subsequent study found benefits in mortality from intentional weight loss in those who have severe obesity.
Dieting
| Treatment | 25-26.9 | 27-29.9 | 30-34.9 | 35-39.9 | ≥40 |
| Lifestyle intervention | Yes | Yes | Yes | Yes | Yes |
| Pharmacotherapy | Not appropriate | With co-morbidities | Yes | Yes | Yes |
| Surgery | Not appropriate | Not appropriate | With co-morbidities | Yes |
Diets to promote weight loss are generally divided into four categories: low-fat, low-carbohydrate, low-calorie, and very low calorie. Several diets are effective. A meta-analysis of six randomized controlled trials found no difference between three of the main diet types, with a weight loss in all studies. At two years these three methods resulted in similar weight loss irrespective of the macronutrients emphasized. High protein diets do not appear to make any difference. A diet high in simple sugars such as those in soft drinks increases weight. There is evidence that dieting alone is efficient for weight loss and improving health for obese individuals.
Dieting for calorie restriction is advised for overweight individuals by the Dietary Guidelines for Americans and United Kingdom's NICE.
Exercise
With use, muscles consume energy derived from both fat and glycogen. Due to the large size of leg muscles, walking, running, and cycling are the most effective means of exercise to reduce body fat. Exercise affects macronutrient balance. During moderate exercise, equivalent to a brisk walk, there is a shift to greater use of fat as a fuel. To maintain health, the American Heart Association recommends a minimum of 30 minutes of moderate exercise at least 5 days a week.The Cochrane Collaboration found that exercising alone led to limited weight loss. In combination with diet, however, it resulted in a 1 kilogram weight loss over dieting alone. A loss was observed with a greater degree of exercise. Even though exercise as carried out in the general population has only modest effects, a dose response curve is found, and very intense exercise can lead to substantial weight loss. During 20 weeks of basic military training with no dietary restriction, obese military recruits lost. High levels of physical activity seem to be necessary to maintain weight loss. A pedometer appears useful for motivation. Over an average of 18-weeks of use physical activity increased by 27% resulting in a 0.38 decreased in BMI.
Signs that encourage the use of stairs as well as community campaigns have been shown to be effective in increasing exercise in a population. The city of Bogota, Colombia for example blocks off of roads every Sunday and on holidays to make it easier for its citizens to get exercise. These pedestrian zones are part of an effort to combat chronic diseases, including obesity.
In an effort to combat the issue, a primary school in Australia instituted a standing classroom in 2013.
There is evidence that exercise alone is not sufficient to produce meaningful weight loss, but combining dieting and exercise provide the greatest health benefits and weight loss on the long term.
Weight loss programs
Weight loss programs involve lifestyle changes including diet modifications, physical activity and behavior therapy. This may involve eating smaller meals, cutting down on certain types of food, and making a conscious effort to exercise more. These programs also enable people to connect with a group of others who are attempting to lose weight, in the hopes that participants will form mutually motivating and encouraging relationships. Since 2013, the United States guidelines recommend to treat obesity as a disease and actively treat obese people for weight loss.A number of popular programs exist, including Weight Watchers, Overeaters Anonymous, and Jenny Craig. These appear to provide modest weight loss over dieting on one's own over a two-year period, similarly to non-commercial diets. Internet-based programs appear to be ineffective.
The Chinese government has introduced a number of "fat farms" where obese children go for reinforced exercise, and has passed a law which requires students to exercise or play sports for an hour a day at school.
In a structured setting with a trained therapist, these interventions produce an average weight loss of up to 8 kg in 6 months to 1 year, and 67% of people who lost greater than 10% of their body mass maintained or continued to lose weight one year later. There is a gradual weight regain after the first year of about 1 to 2 kg per year, but on the long-term this still results in a weight loss.
Comprehensive diet programs, providing counseling, targets for calorie intake and exercise, may be more efficient than dieting without guidance, although the evidence is very limited. Following comprehensive lifestyle modifications, the average maintained weight loss is more than or 3% of total body mass, and could be sustained for five years, and up to 20% of the individuals maintain a weight loss of at least 10%. There is some evidence that fast weight loss produce greater long-term weight loss than gradual weight loss. Moderate on-site comprehensive lifestyle changes produce a greater weight loss than usual care, of 2 to 4 kg on average in 6 to 12 months. High-intensity comprehensive programs usually yield more weight loss than moderate or low-intensity, with about 35% to 60% of overweight individuals maintaining more than 5 kg weight loss after 2 years.
The NICE devised a set of essential criteria to be met by commercial weight management organizations to be approved.
Medication
Several anti-obesity medications are currently approved by the FDA for long term use. Orlistat reduces intestinal fat absorption by inhibiting pancreatic lipase.Lorcaserin has been found to be effective in the treatment of obesity with a weight loss of 5.8 kg at one year as opposed to 2.2 kg with placebo and it is approved by the Food and Drug Administration for use in the treatment of obesity. Side effects may include serotonin syndrome.
The combination drug phentermine/topiramate is approved by the FDA as an addition to a reduced-calorie diet and exercise for chronic weight management.
Rimonabant, another drug, had been withdrawn from the market. It worked via a specific blockade of the endocannabinoid system. It has been developed from the knowledge that cannabis smokers often experience hunger, which is often referred to as "the munchies". It had been approved in Europe for the treatment of obesity but has not received approval in the United States or Canada due to safety concerns. European Medicines Agency in October 2008 recommended the suspension of the sale of rimonabant as the risk seem to be greater than the benefits. Sibutramine, which acts in the brain to inhibit deactivation of the neurotransmitters, thereby decreasing appetite was withdrawn from the UK market in January 2010 and United States and Canadian markets in October 2010 due to cardiovascular concerns.
Weight loss with these drugs is modest. Over the longer term, average weight loss on orlistat is, sibutramine is and rimonabant is. Orlistat and rimonabant lead to a reduced incidence of diabetes, and all three drugs have some effect on cholesterol. However, there is little information on how these drugs affect the longer-term complications or outcomes of obesity. In 2010 it was found that sibutramine increases the risk of heart attacks and strokes in people with a history of cardiovascular disease.
There are a number of less commonly used medications. Some are only approved for short term use, others are used off-label, and still others are used illegally. Most are appetite suppressants that act on one or more neurotransmitters. Racemic amphetamine, phendimetrazine, diethylpropion, and phentermine are approved by the FDA for short term use, while bupropion, topiramate, and zonisamide are sometimes used off-label. Recombinant human leptin is very effective in those with obesity due to congenital complete leptin deficiency via decreasing energy intake and possibly increases energy expenditure. This condition is, however, rare and this treatment is not effective for inducing weight loss in the majority of people with obesity. It is being investigated to determine whether or not it helps with weight loss maintenance.
The usefulness of certain drugs depends upon the comorbidities present. Metformin is preferred in overweight diabetics, as it may lead to mild weight loss in comparison to sulfonylureas or insulin. The thiazolidinediones, on the other hand, may cause weight gain, but decrease central obesity. Diabetics also achieve modest weight loss with fluoxetine, orlistat and sibutramine over 12–57 weeks. Preliminary evidence has however found higher number of cardiovascular events in people taking sibutramine verses control. The long-term health benefits of these treatments remain unclear.
Fenfluramine and dexfenfluramine were withdrawn from the market in 1997, while ephedrine was removed from the market in 2004.
Though hypothesized that supplementation of vitamin D may be an effective treatment for obesity, studies do not support this. There is also no strong evidence to recommend herbal medicines for weight loss.
Surgery
is the use of surgical intervention in the treatment of obesity. As every operation may have complications, surgery is only recommended for severely obese people who have failed to lose weight following dietary modification and pharmacological treatment. Weight loss surgery relies on various principles: the two most common approaches are reducing the volume of the stomach, which produces an earlier sense of satiation, and reducing the length of bowel that comes into contact with food, which directly reduces absorption. Band surgery is reversible, while bowel shortening operations are not. Some procedures can be performed laparoscopically. Complications from weight loss surgery are frequent.Surgery for severe obesity is associated with long-term weight loss and decreased overall mortality. One study found a weight loss of between 14% and 25% at 10 years, and a 29% reduction in all cause mortality when compared to standard weight loss measures. A marked decrease in the risk of diabetes mellitus, cardiovascular disease and cancer has also been found after bariatric surgery. Marked weight loss occurs during the first few months after surgery, and the loss is sustained in the long term. In one study there was an unexplained increase in deaths from accidents and suicide, but this did not outweigh the benefit in terms of disease prevention. When the two main techniques are compared, gastric bypass procedures are found to lead to 30% more weight loss than banding procedures one year after surgery. For obese individuals with non-alcoholic fatty liver disease, bariatric surgery improves or cures the liver.
A preoperative diet such as low-calorie diets or very-low-calorie diet, is usually recommended to reduce liver volume by 16-20%, and preoperative weight loss is the only factor associated with postoperative weight loss. Preoperative weight loss can reduce operative time and hospital stay. although there is insufficient evidence whether preoperative weight loss may be beneficial to reduce long-term morbidity or complications. Weight loss and decreases in liver size may be independent from the amount of calorie restriction.
Ileojejunal bypass, in which the digestive tract is rerouted to bypass the small intestine, was an experimental surgery designed as a remedy for morbid obesity.
The effects of liposuction on obesity are less well determined. Some small studies show benefits while others show none. A treatment involving the placement of an intragastric balloon via gastroscopy has shown promise. One type of balloon led to a weight loss of 5.7 BMI units over 6 months or. Regaining lost weight is common after removal, however, and 4.2% of people were intolerant of the device.
An implantable nerve simulator which improves the feeling of fullness was approved by the FDA in 2015.
In 2016 the FDA approved an aspiration therapy device that siphons food from the stomach to the outside and decreases caloric intake. As of 2015 one trial shows promising results.
Clinical protocols
Much of the Western world has created clinical practice guidelines in an attempt to address rising rates of obesity. Australia, Canada, the European Union, and the United States have all published statements since 2004.In a clinical practice guideline by the American College of Physicians, the following five recommendations are made:
- People with a BMI of over 30 should be counseled on diet, exercise and other relevant behavioral interventions, and set a realistic goal for weight loss.
- If these goals are not achieved, pharmacotherapy can be offered. The person needs to be informed of the possibility of side-effects and the unavailability of long-term safety and efficacy data.
- Drug therapy may consist of sibutramine, orlistat, phentermine, diethylpropion, fluoxetine, and bupropion. For more severe cases of obesity, stronger drugs such as amphetamine and methamphetamine may be used on a selective basis. Evidence is not sufficient to recommend sertraline, topiramate, or zonisamide.
- In people with a BMI over 40 who fail to achieve their weight loss goals and who develop obesity-related complications, referral for bariatric surgery may be indicated. The person needs to be aware of the potential complications.
- Those requiring bariatric surgery should be referred to high-volume referral centers, as the evidence suggests that surgeons who frequently perform these procedures have fewer complications.
Canada developed and published evidence-based practice guidelines in 2006. The guidelines attempt to address the prevention and management of obesity at both the individual and population levels in both children and adults. The European Union published clinical practice guidelines in 2008 in an effort to address the rising rates of obesity in Europe. Australia came out with practice guidelines in 2004.
Research
Temporary, controllable gastric pseudo-bezoars are being tested.Treatment with naltrexone plus bupropion in a phase three trial resulted in a weight lose of 5–6% versus 1% for a placebo.