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.

As of 2015 there is not good evidence comparing surgery to lifestyle change for obesity in children. There are a number of high quality ongoing studies looking at this issue.

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.

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.

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.

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.

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.

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.

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.

Obesity in Canada is a growing health concern, which is "expected to surpass smoking as the leading cause of preventable morbidity and mortality … and represents a burden of Can$3.96 (US$3.04/€2.75) billion on the Canadian economy each year."

Until the late 20th century, dietary issues in Mexico were solely a question of undernutrition or malnutrition, generally because of poverty and distribution issues. For this reason, obesity was associated with wealth and health, the latter especially in children. Despite changes in the Mexican diet and food distribution, malnutrition still remains problematic in various parts of the country.

Obesity in Mexico is a relatively recent phenomenon, having been widespread since the 1980s with the introduction of processed food into much of the Mexican food market. Prior to that, dietary issues were limited to under and malnutrition, which is still a problem in various parts of the country. Following trends already ongoing in other parts of the world, Mexicans have been foregoing traditional whole grains and vegetables in favor of a diet with more animal products, more fat, and more sugar much of which is a consequence of processed food. It has seen dietary energy intake and rates of overweight and obese people rise with seven out of ten at least overweight and a third clinically obese.

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.

According to 2007 statistics from the World Health Organization (WHO), Australia has the third-highest prevalence of overweight adults in the English-speaking world.Obesity in Australia is an "epidemic" with "increasing frequency." "The Medical Journal of Australia" found that obesity in Australia more than doubled in the two decades preceding 2003, and the unprecedented rise in obesity has been compared to the same health crisis in America. The rise in obesity has been attributed to poor eating habits in the country closely related to the availability of fast food since the 1970s, sedentary lifestyles and a decrease in the labour workforce.

Obesity in North Africa and the Middle East is a notable health issue. In 2005, the World Health Organization measured that 1.6 billion people were overweight and 400 million were obese. It estimates that by the year 2015, 2.3 billion people will be overweight and 700 million will be obese. The Middle East, including the Arabian Peninsula, Eastern Mediterranean, Turkey and Iran, and North Africa, are no exception to the worldwide increase in obesity. Subsequently, some call this trend the New World Syndrome. The lifestyle changes associated with the discovery of oil and the subsequent increase in wealth is one contributing factor.

Urbanization has occurred rapidly and has been accompanied by new technologies that promote sedentary lifestyles. Due to accessibility of private cars, television, and household appliances, the population as a whole is engaging in less physical activity. The rise in caloric and fat intake in a region where exercise is not a defining part of the culture has added to the overall increased percentages of overweight and obese populations. In addition, women are more likely to be overweight or obese due to cultural norms and perceptions of appropriate female behavior and occupations inside and outside of the home.

Obesity in Greece is a growing health concern with health officials stating that it is one of the leading causes of preventable deaths in Greece.

Obesity in Nauru is a major health concern for the nation. In 2007 Forbes.com reported that, according to the World Health Organization's (WHO) latest estimate, Nauru has the highest percentage of overweight inhabitants among all countries. The estimation identified 94.5% of its residents as overweight. The obesity rate is 71.7%, the highest in the world. The definition of "overweight" and "obesity" are based on body mass index (BMI). People with BMI more than or equal to 25 are classified as overweight, and people with BMI more than or equal to 30 are classified as obese.

The average body weight among Nauruans is estimated to be approximately . Nauru has an average BMI between 34 and 35.

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

Weight is measured by using the Body Mass Index scale (BMI). This is determined by dividing weight in kilograms by height in metres, squared. If someone is overweight their BMI will be at 25 or more. If someone is obese their BMI will be at 30 or more.

Obesity in Germany has been increasingly cited as a major health issue in recent years. The federal government has declared this to be a major issue.

Data released by the World Health Organisation in 2014 showed that while an issue of growing concern, within the European Union, Germany had a lower incidence of overweight and obese adults as a percentage of the total population at 54.8% in comparison with France at 60.7%, Spain at 60.9% or the United Kingdom at 63.4%.

Various groups including government, food and health care professionals have made attempts to highlight and address the causes and growing problem of obesity in the United Kingdom.

Obesity in China is a major health concern according to the WHO, with overall rates of obesity below 5% in the country, but greater than 20% in some cities. This is a dramatic change from times when China experienced famine as a result from ineffective agriculturalization plans such as the Great Leap Forward.

Currently, obesity in China is mostly confined to the cities where fast food culture and globalization have taken over, in comparison to poorer rural areas. Despite this concentration of obesity, the sheer size of China's population means that over one fifth of all one billion obese people in the world come from China.

Obesity in the United States has been increasingly cited as a major health issue in recent decades, resulting in diseases such as coronary heart disease that lead to mortality. While many industrialized countries have experienced similar increases, obesity rates in the United States are the highest in the world.

Obesity has continued to grow within the United States. Two of every three American men are considered to be overweight or obese, but the rates for women are far higher. The United States contains one of the highest percentage of obese people in the world. An obese person in America incurs an average of $1,429 more in medical expenses annually. Approximately $147 billion is spent in added medical expenses per year within the United States. This number is suspected to increase approximately $1.24 billion per year until the year 2030.

The United States had the highest rate of obesity within the OECD grouping of large trading economies. From 23% obesity in 1962, estimates have steadily increased. The following statistics comprise adults age 20 and over. The overweight percentages for the overall US population are higher reaching 39.4% in 1997, 44.5% in 2004, 56.6% in 2007, and 63.8% (adults) and 17% (children) in 2008. In 2010, the Centers for Disease Control and Prevention (CDC) reported higher numbers once more, counting 65.7% of American adults as overweight, and 17% of American children, and according to the CDC, 63% of teenage girls become overweight by age 11. In 2013 the Organisation for Economic Co-operation and Development (OECD) found that 57.6% of American citizens were obese. The organization estimates that 3/4 of the American population will likely be overweight or obese by 2020. The latest figures from the CDC as of 2014 show that more than one-third (36.5%) of U.S. adults age 20 and older and 17% of children and adolescents aged 2–19 years were obese. A second study from the National Center for Health Statistics at the CDC showed that 39.6% of US adults age 20 and older were obese as of 2015-2016 (37.9% for men and 41.1% for women).

Obesity has been cited as a contributing factor to approximately 100–400 000 deaths in the United States per year and has increased health care use and expenditures, costing society an estimated $117 billion in direct (preventive, diagnostic, and treatment services related to weight) and indirect (absenteeism, loss of future earnings due to premature death) costs. This exceeds health care costs associated with smoking and accounts for 6% to 12% of national health care expenditures in the United States.

According to Cleveland Clinic, cultural, social, and environmental factors, among others, all affect eating behaviors.