There are no medications currently approved for the treatment of obesity in children. The American Academy of Pediatrics recommends medications for obesity be discourage. Orlistat and sibutramine may be helpful in managing moderate obesity in adolescence. Metformin is minimally useful. A Cochrane review in 2016 concluded that medications might reduce BMI and bodyweight to a small extent in obese children and adolescents. This conclusion was based only on low quality evidence.

The main treatment for obesity consists of dieting and physical exercise. Diet programs may produce weight loss over the short term, but maintaining this weight loss is frequently difficult and often requires making exercise and a lower food energy diet a permanent part of a person's lifestyle.

In the short-term low carbohydrate diets appear better than low fat diets for weight loss. In the long term; however, all types of low-carbohydrate and low-fat diets appear equally beneficial. A 2014 review found that the heart disease and diabetes risks associated with different diets appear to be similar. Promotion of the Mediterranean diets among the obese may lower the risk of heart disease. Decreased intake of sweet drinks is also related to weight-loss. Success rates of long-term weight loss maintenance with lifestyle changes are low, ranging from 2–20%. Dietary and lifestyle changes are effective in limiting excessive weight gain in pregnancy and improve outcomes for both the mother and the child. Intensive behavioral counseling is recommended in those who are both obese and have other risk factors for heart disease.

Five medications have evidence for long-term use orlistat, lorcaserin, liraglutide, phentermine–topiramate, and naltrexone–bupropion. They result in weight loss after one year ranged from 3.0 to 6.7 kg over placebo. Orlistat, liraglutide, and naltrexone–bupropion are available in both the United States and Europe, whereas lorcaserin and phentermine–topiramate are available only in the United States. European regulatory authorities rejected the latter two drugs in part because of associations of heart valve problems with lorcaserin and more general heart and blood vessel problems with phentermine–topiramate. Orlistat use is associated with high rates of gastrointestinal side effects and concerns have been raised about negative effects on the kidneys. There is no information on how these drugs affect longer-term complications of obesity such as cardiovascular disease or death.

The most effective treatment for obesity is bariatric surgery. The types of procedures include laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, vertical-sleeve gastrectomy, and biliopancreatic diversion. Surgery for severe obesity is associated with long-term weight loss, improvement in obesity related conditions, and decreased overall mortality. One study found a weight loss of between 14% and 25% (depending on the type of procedure performed) at 10 years, and a 29% reduction in all cause mortality when compared to standard weight loss measures. Complications occur in about 17% of cases and reoperation is needed in 7% of cases. Due to its cost and risks, researchers are searching for other effective yet less invasive treatments including devices that occupy space in the stomach.

Obesity in children is treated with dietary changes and physical activity. Dieting and missing meals should; however, be discourage. The benefit of tracking BMI and providing counselling around weight is minimal.

Weight management has two steps: weight loss and weight maintenance. In the weight loss phase, energy intake from food must be less than the energy expended each day. Achieving weight loss in cats and dogs is challenging, and failure to lose weight is common.

Medical treatments have been developed to assist dogs in losing weight. Dirlotapide (brand name Slentrol) and mitratapide (brand name Yarvitan) were authorized for use in the EU by the European Medicines Agency for helping weight loss in dogs, by reducing appetite and food intake, but both of these drugs have been withdrawn from the market in the EU. The US Food and Drug Administration approved dirlotapide in 2007. Up to 20% of dogs treated with either dirlotapide or mitratapide experience vomiting and diarrhea; less commonly, anorexia may occur. When these drugs are stopped, the dog's appetite returns to previous levels. If other weight-loss strategies are not employed, the dog will again gain weight.

Although there are many short- term preventative methods in place to combat childhood, there are some individuals who return to their initial base weight and therefore might turn to surgical measures to achieve a more lasting effect. Bariatric surgery is an effective procedure used to restrict the patients food intake and decrease absorption of food in the stomach and intestines. Proecdures of this type are said to be able to reduce excess body weight of obese or overweight individuals by 50-75%, ultimately maintaining this weight loss for 16 years following.

The usual treatments for overweight individuals is diet and physical exercise.

Dietitians generally recommend eating several balanced meals dispersed through the day, with a combination of progressive, primarily aerobic, physical exercise.

Because these general treatments help most case of obesity, they are common in all levels of overweight individuals.

A permanent routine of exercise, eating healthily, and, during periods of being overweight, consuming the same number or fewer calories than used will prevent and help fight obesity. A single pound of fat yields approximately 3500 calories of energy (32 000 kJ energy per kilogram of fat), and weight loss is achieved by reducing energy intake, or increasing energy expenditure, thus achieving a negative balance. Adjunctive therapies which may be prescribed by a physician are orlistat or sibutramine, although the latter has been associated with increased cardiovascular events and strokes and has been withdrawn from the market in the United States, the UK, the EU, Australia, Canada, Hong Kong, Thailand, Egypt and Mexico.

A 2006 study published in the International Journal of Sport Nutrition and Exercise Metabolism, suggests that combining cardiovascular (aerobic) exercise with resistance training is more effective than cardiovascular training alone in getting rid of abdominal fat. An additional benefit to exercising is that it reduces stress and insulin levels, which reduce the presence of cortisol, a hormone that leads to more belly fat deposits.

Self-motivation by understanding the risks associated with abdominal obesity is widely regarded as being far more important than worries about cosmetics. In addition, understanding the health issues linked with abdominal obesity can help in the self-motivation process of losing the abdominal fat. As mentioned above, abdominal fat is linked with cardiovascular disease, diabetes, and cancer. Specifically it's the deepest layer of belly fat (the fat you cannot see or grab) that poses health risks, as these "visceral" fat cells produce hormones that can affect health (e.g. increased insulin resistance and/or breast cancer risk). The risk increases considering the fact that they are located in the proximity or in between organs in the abdominal cavity. For example, fat next to the liver drains into it, causing a fatty liver, which is a risk factor for insulin resistance, setting the stage for Type 2 diabetes.

In the presence of diabetes mellitus type 2, the physician might instead prescribe metformin and thiazolidinediones (rosiglitazone or pioglitazone) as antidiabetic drugs rather than sulfonylurea derivatives. Thiazolidinediones may cause slight weight gain but decrease "pathologic" abdominal fat (visceral fat), and therefore may be prescribed for diabetics with central obesity.

Thiazolidinedione has been associated with heart failure and increased cardiovascular risk; so it has been withdrawn from the market in Europe by EMA in 2010.

Low-fat diets may not be an effective long-term intervention for obesity: as Bacon and Aphramor wrote, "The majority of individuals regain virtually all of the weight that was lost during treatment." The Women's Health Initiative ("the largest and longest randomized, controlled dietary intervention clinical trial") found that long-term dietary intervention increased the waist circumference of both the intervention group and the control group, though the increase was smaller for the intervention group. The conclusion was that mean weight decreased significantly in the intervention group from baseline to year 1 by 2.2 kg (P<.001) and was 2.2 kg less than the control group change from baseline at year 1. This difference from baseline between control and intervention groups diminished over time, but a significant difference in weight was maintained through year 9, the end of the study.

During pregnancy, doctors recommend light exercise. Doctors state that exercise can help the comfort of the mother and the well-being of the unborn child. Some benefits include, but are not limited to: reduced back pain, decrease in constipation, less likely to gain excess weight, decreased chance of gestational diabetes, easier labor, quicker recovery, and better physical and emotional health of the baby.

If negative signs and symptoms occur after exercising, pregnant females should stop immediately. Some signs include: dizziness, faintness, headache, shortness of breath, uterine contractions, vaginal bleeding, fluid leaking, or heart palpitations.

There are many options available in treating obesity, such as: altering one's diet and exercising regularly. Moderate forms of exercise, such as walking, can lead to healthy weight loss. Some people who are obese turn to gastric bypass surgery in order to reduce their appetites. It is always advised to consult a physician regarding any obesity treatment.

It is recommended that obese women should try to lose weight before becoming pregnant, yet women should not diet during pregnancy because sufficient nutrition is important for pregnant women and women planning pregnancy. Women with gastric banding can have normal pregnancies and better outcomes than women who do not have the surgery, but in most cases, doctors have agreed that pregnancy should wait until surgery-related weight loss has stabilized. Clinicians have been encouraged to talk to women who are pregnant or may become pregnant about getting enough folic acid, quitting smoking, and avoiding alcohol. Women are also recommended to have appropriate calorie intake and exercise adequately.

The first line treatment is change of lifestyle (e.g., Dietary Guidelines for Americans and physical activity). However, if in three to six months of efforts at remedying risk factors prove insufficient, then drug treatment is frequently required. Generally, the individual disorders that compose the metabolic syndrome are treated separately. Diuretics and ACE inhibitors may be used to treat hypertension. Cholesterol drugs may be used to lower LDL cholesterol and triglyceride levels, if they are elevated, and to raise HDL levels if they are low. Use of drugs that decrease insulin resistance, e.g., metformin and thiazolidinediones, is controversial; this treatment is not approved by the U.S. Food and Drug Administration. Weight loss medications may result in weight loss. As obesity is often recognized as the culprit behind many of the additional symptoms, with weight loss and lifestyle changes in diet, physical activity, the need for other medications may diminish.

A 2003 study indicated cardiovascular exercise was therapeutic in approximately 31% of cases. The most probable benefit was to triglyceride levels, with 43% showing improvement; but fasting plasma glucose and insulin resistance of 91% of test subjects did not improve.

Many other studies have supported the value of physical activity and dietary modifications to treat metabolic syndrome. Some natural compounds, like ursolic acid, have been suggested as a treatment for obesity/metabolic syndrome based on the results of extensive research involving animal models; it is argued, however, that there is still a lack of data regarding the use of ursolic acid in humans, as phase-II/III trials of that drug have not been carried so far.

Restricting the overall dietary carbohydrate intake is more effective in reducing the most common symptoms of metabolic syndrome than the more commonly prescribed reduction in dietary fat intake.

The combination preparation simvastatin/sitagliptin (marketed as Juvisync) was introduced in 2011 and the use of this drug was to lower LDL levels and as well as increase insulin levels. This drug could have been used to treat metabolic syndrome but was removed from the market by Merck in 2013 due to business reasons.

High-dose statins, recommended to reduce cardiovascular risk, have been associated with higher progression to diabetes, particularly in patients with metabolic syndrome. The biological mechanisms are not entirely understood, however, the plausible explanation may lie in competitive inhibition of glucose transport via the solute carrier (SLC) family of transporters (specifically "SLCO1B1"), important in statin pharmacokinetics.

Some studies on mice suggest that a Time Restricted Diet (TRD) could be helpful in reversing obesity and possibly metabolic syndrome

Treatment is typically achieved via diet and exercise, although metformin may be used to reduce insulin levels in some patients (typically where obesity is present). A referral to a dietician is beneficial. Another method used to lower excessively high insulin levels is cinnamon as was demonstrated when supplemented in clinical human trials.

A low carbohydrate diet is particularly effective in reducing hyperinsulinism.

A healthy diet that is low in simple sugars and processed carbohydrates, and high in fiber, and vegetable protein is often recommended. This includes replacing white bread with whole-grain bread, reducing intake of foods composed primarily of starch such as potatoes, and increasing intake of legumes and green vegetables, particularly soy.

Regular monitoring of weight, blood sugar, and insulin are advised, as hyperinsulinemia may develop into diabetes mellitus type 2.

It has been shown in many studies that physical exercise improves insulin sensitivity. The mechanism of exercise on improving insulin sensitivity is not well understood however it is thought that exercise causes the glucose receptor GLUT4 to translocate to the membrane. As more GLUT4 receptors are present on the membrane more glucose is taken up into cells decreasing blood glucose levels which then causes decreased insulin secretion and some alleviation of hyperinsulinemia. Another proposed mechanism of improved insulin sensitivity by exercise is through AMPK activity. The beneficial effect of exercise on hyperinsulinemia was shown in a study by Solomon et al. (2009), where they found that improving fitness through exercise significantly decreases blood insulin concentrations.

An appropriate weight training and weight loss program can help to improve the patient's condition.

The two most common forms of treatment that are crucial for individuals to carry out to combat obesity include changing to a healthier diet and increasing their physical exercise. In extreme cases, if children are morbidly obese bariatric surgery may be carried out.

Certain physical and mental illnesses and the pharmaceutical substances used to treat them can increase risk of obesity. Medical illnesses that increase obesity risk include several rare genetic syndromes (listed above) as well as some congenital or acquired conditions: hypothyroidism, Cushing's syndrome, growth hormone deficiency, and the eating disorders: binge eating disorder and night eating syndrome. However, obesity is not regarded as a psychiatric disorder, and therefore is not listed in the DSM-IVR as a psychiatric illness. The risk of overweight and obesity is higher in patients with psychiatric disorders than in persons without psychiatric disorders.

Certain medications may cause weight gain or changes in body composition; these include insulin, sulfonylureas, thiazolidinediones, atypical antipsychotics, antidepressants, steroids, certain anticonvulsants (phenytoin and valproate), pizotifen, and some forms of hormonal contraception.

The term "non-syndromic obesity" is sometimes used to exclude these conditions. In people with early-onset severe obesity (defined by an onset before 10 years of age and body mass index over three standard deviations above normal), 7% harbor a single locus mutation.

Compared to non-obese animals, obese dogs and cats have a higher incidence of osteoarthritis (joint disease) and diabetes mellitus, which also occur earlier in the life of the animal. Obese animals are also at increased risk of complications following anesthesia or surgery.

Obese dogs are more likely to develop urinary incontinence, may have difficulty breathing, and overall have a poorer quality of life compared to non-obese dogs, as well as having a lower life expectancy. Obese cats have an increased risk of diseases affecting the mouth and urinary tract. Obese cats which have difficulty grooming themselves are predisposed to dry, flaky skin and feline acne.

Various strategies have been proposed to prevent the development of metabolic syndrome. These include increased physical activity (such as walking 30 minutes every day), and a healthy, reduced calorie diet. Many studies support the value of a healthy lifestyle as above. However, one study stated these potentially beneficial measures are effective in only a minority of people, primarily due to a lack of compliance with lifestyle and diet changes. The International Obesity Taskforce states that interventions on a sociopolitical level are required to reduce development of the metabolic syndrome in populations.

The Caerphilly Heart Disease Study followed 2,375 male subjects over 20 years and suggested the daily intake of a pint (~568 ml) of milk or equivalent dairy products more than halved the risk of metabolic syndrome. Some subsequent studies support the authors' findings, while others dispute them. A systematic review of four randomized controlled trials found that a paleolithic nutritional pattern improved three of five measurable components of the metabolic syndrome in participants with at least one of the components.

There is a common misconception that spot exercise (that is, exercising a specific muscle or location of the body) most effectively burns fat at the desired location, but this is not the case. Spot exercise is beneficial for building specific muscles, but it has little effect, if any, on fat in that area of the body, or on the body's distribution of body fat. The same logic applies to sit-ups and belly fat. Sit-ups, crunches and other abdominal exercises are useful in building the abdominal muscles, but they have little effect, if any, on the adipose tissue located there.

While the negative health outcomes associated with obesity are accepted within the medical community, the health implications of the overweight category are more controversial. The generally accepted view is that being overweight causes similar health problems to obesity, but to a lesser degree. A 2016 review estimated that the risk of death increases by seven percent among overweight people with a BMI of 25 to 27.5 and 20 percent among overweight people with a BMI of 27.5 to 30. The Framingham heart study found that being overweight at age 40 reduced life expectancy by three years. Being overweight also increases the risk of oligospermia and azoospermia in men.

Katherine Flegal et al., however, found that the mortality rate for individuals who are classified as overweight (BMI 25 to 30) may actually be lower than for those with an "ideal" weight (BMI 18.5 to 25).

Being overweight has been identified as a cause of cancer, and is projected to overtake smoking as the primary cause of cancer in developed countries as cases of cancer linked to smoking dwindle.

Psychological well-being is also at risk in the overweight individual due to social discrimination. However, children under the age of eight are normally not affected.

Being overweight has been shown not to increase mortality in older people: in a study of 70 to 75-year old Australians, mortality was lowest for "overweight" individuals (BMI 25 to 30), while a study of Koreans found that, among those initially aged 65 or more, an increase in BMI to above 25 was not associated with increased risk of death.

Like many other medical conditions, obesity is the result of an interplay between environmental and genetic factors. Studies have identified variants in several genes that may contribute to weight gain and body fat distribution; although, only in a few cases are genes the primary cause of obesity.

Polymorphisms in various genes controlling appetite and metabolism predispose to obesity under certain dietary conditions. The percentage of obesity that can be attributed to genetics varies widely, depending on the population examined, from 6% to 85%. As of 2006, more than 41 sites on the human genome have been linked to the development of obesity when a favorable environment is present. The involvement of genetic factors in the development of obesity is estimated to be 40–70%. Some of these obesogenic or leptogenic genes may influence obese individuals response to weight loss or weight management.

Obesity has been observed throughout human history. Many early depictions of the human form in art and sculpture appear obese. However, it was not until the 20th century that obesity became common — so much so that, in 1997, the World Health Organization (WHO) formally recognized obesity as a global epidemic. Obesity is defined as having a body mass index (BMI) greater than or equal to 30 kg/m, and in June 2013 the American Medical Association classified it as a disease, with much controversy.

In countries of the Organisation for Economic Co-operation and Development (OECD), one child out of five is overweight or obese. Once considered a problem only of high-income countries, obesity rates are rising worldwide. Globally, there are now more people who are obese than who are underweight, a trend observed in every region over the world except parts of sub-Saharan Africa and Asia. In 2013, an estimated 2.1 billion adults were overweight, as compared with 857 million in 1980. Of adults who are overweight, 31% are obese. Increases in obesity have been seen most in urban settings.

Since body fat can be measured in several ways, statistics on the epidemiology of obesity vary between sources. While BMI is the most basic and commonly used indicator of obesity, other measures include waist circumference, waist-to-hip ratio, skinfold thicknesses, and bioelectrical impedance. The rate of obesity increases with age at least up to 50 or 60 years old.

The OECD notes that — given the health, economic, and social consequences of obesity — many countries have built multi-stakeholder networks involving civil society and the business sector in order to devise appropriate public health policies and solutions for obesity prevention.

Obesity in India has reached epidemic proportions in the 21st century, with morbid obesity affecting 5% of the country's population. India is following a trend of other developing countries that are steadily becoming more obese. Unhealthy, processed food has become much more accessible following India's continued integration in global food markets. This, combined with rising middle class incomes, is increasing the average caloric intake per individual among the middle class and above income households. Obesity is a major risk factor for cardiovascular disease, NGOs such as the Indian Heart Association have been raising awareness about this issue.

While studying 22 different SNPs near to MC-R gene, scientists have identified a SNP (single nucleotide polymorphism) named rs12970134 to be mostly associated with waist circumference. In this study more than two thousand individuals of Indian origin participated and the aforementioned SNP is highly prevalent in this group.

Internationally, a BMI over 25 kg/m2 is considered overweight. Due to genetic tendency of Indians towards abdominal obesity and its associated risk of related lifestyle diseases like Diabetes & Heart Disease, Guidelines for diagnosis of obesity and abdominal obesity for India have been published in JAPI (2009) that a BMI over 23 kg/m2 is considered overweight. Further definitions: Normal BMI: 18.0-22.9 kg/m2, Overweight: 23.0-24.9 kg/m2, Obesity: >25 kg/m2.

The body mass index (BMI) does not capture information about percentage body fat (PBF), which is a better predictor of risk due to obesity.

The term "metabolically obese normal weight" (MONW) refers to people with normal weight and BMI, but who display some metabolic characteristics that may increase the risk of developing metabolic syndrome, in the same way as obesity. MONW subjects have excess visceral fat, and are predisposed to insulin resistance, hypertension and cardiovascular disease. These people show benefits from energy restriction and weight loss, for example a 4- to 12-week period of diet and exercise.

Some studies have suggested that the main factor which explains the metabolic abnormalities in MONW individuals is fat distribution. On the basis of these studies, a scoring method has been proposed to identify MONW individuals, based on the presence of associated diseases or biochemical abnormalities related to insulin resistance.

Several studies have shown that obese men tend to have a lower sperm count, fewer rapidly mobile sperm and fewer progressively motile sperm compared to normal-weight men.

Obesity in Germany has created a cholesterol problem. High cholesterol is known to cause premature death, angina, heart disease and strokes.

There has been an increase of children with Type 1 diabetes between 1996 and 2011. Diabetics are at higher risk for complications such as heart attack and stroke. In Germany, 600,000 people suffered from diabetes near the end of World War II compared to eight million now.

Obesity can increased risk for secondary diseases such as diabetes, cardiovascular disease, certain cancers and Alzheimer's. Children who get diabetes can expect to lose 10 to 15 years off of their lives. Diabetes also affect the eyes, kidneys and nerves in the legs.

Obesity is a "very strong promoter of cancer." Obesity causes an increased risk for colon cancer and breast cancer.

HAIR-AN syndrome as discussed earlier is caused by both gentic and environmental factors. It is found out that women affected by this syndrome or PCOS (polycystic ovary syndrome) are generally accompanied by obesity. Weight loss is most suggested way to combat this syndrome and is helpful for reducing insulin resistance of the body. It is also a good way to have a control on diet. This might help the body to refunction properly and show some resistance to HAIR-AN syndrome. "Suppression of gonadotropin with estrogen-progesterone oral contraceptives" or can say as reducing hyperandrogenism by the use of estoprogestatif can reduce production of androgen by ovaries by cutting down the LH (leutinizing hormone) level in body. Even their sex hormone binding to globulin increase is also responsible for decreasing body's bio-availability of testosterone. There are also few pills of new progestins, such as desogestrel and norgestimate. This pills appear to have fewer androgenic side effects and may be safer to use in persons with abnormal lipid levels or hirsutism. Some antiandrogenic agents can be also used alone or combining it with other oral pills.

"Spironolactone inhibit the actions of testosterone by binding to its receptors." The standard dose for its use is considered to be 50 to 100 mg twice a day. This might lead to irregular menstrual bleeding, which can be improved by oral contraceptives. Flutamide, an another antiandorgen that is used to treat HAIR-AN syndrome, but it has risk of hepatotoxicity. Finasteride is a 5α-reductase inhibitor which can reduces the conversion of testosterone to dihydrotestosterone. It is useful in the treatment of hirsutism with a dosages as low as 5 mg per day.

Insulin-resistant patients can also be treated with metformin which has shown promising results to reduce the insulin resistivity. Metformin improves peripheral tissue sensitivity to insulin but inhibits hepatic glucose formation. The drug reduces the levels of circulating insulin and androgens. Women have shown improved reproductive functioning after the use of metformin.