Obesity is a complex disorder involving an excessive amount of body fat. Obesity isn't just a cosmetic concern. It increases your risk of diseases and health problems such as heart disease, diabetes and high blood pressure.
Being extremely obese means you are especially likely to have health problems related to your weight.
The good news is that even modest weight loss can improve or prevent the health problems associated with obesity. Dietary changes, increased physical activity and behavior changes can help you lose weight. Prescription medications or weight-loss surgery also may be options for treating obesity.
Obesity is likely when an individual's body mass index (BMI) is 30 or higher. Your body mass index is calculated by dividing your weight in kilograms (kg) by your height in meters (m) squared.
When to see a doctor
If you think you may be obese, and especially if you're concerned about weight-related health problems, see your primary care doctor. You and your provider can evaluate your health risks and discuss your weight-loss options.
Although there are genetic and hormonal influences on body weight, obesity occurs when you take in more calories than you burn through exercise and normal daily activities. Your body stores these excess calories as fat. Obesity usually results from a combination of causes and contributing factors, including:
- Inactivity. If you're not very active, you don't burn as many calories. With a sedentary lifestyle, you can easily take in more calories every day than you use through exercise and normal daily activities.
- Unhealthy diet and eating habits. Having a diet that's high in calories, lacking in fruits and vegetables, full of fast food, missing breakfast, and laden with high-calorie beverages and oversized portions all contribute to weight gain.
- Pregnancy. During pregnancy, a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women.
- Lack of sleep. Too little sleep can cause changes in hormones that increase your appetite. You may also crave foods high in calories and carbohydrates, which can contribute to weight gain.
- Certain medications. Some medications can lead to weight gain if you don't compensate through diet or activity. These medications include some anti-seizure medications, antipsychotic medications, and corticosteroids.
- Medical problems. Obesity can sometimes be traced to a medical cause, such as Prader-Willi syndrome, Cushing's syndrome, and other diseases and conditions. Some medical problems, such as arthritis, can lead to decreased activity, which may result in weight gain. A low metabolism is unlikely to cause obesity, as is having low thyroid function.
- Genetics. Your genes may affect the amount of body fat you store and where that fat is distributed. Genetics may also play a role in how efficiently your body converts food into energy and how your body burns calories during exercise. Even when someone has a genetic predisposition, environmental factors ultimately make you gain more weight.
- Family lifestyle. Obesity tends to run in families. That's not just because of genetics. Family members tend to have similar eating, lifestyle and activity habits. If one or both of your parents are obese, your risk of being obese is increased.
- Quitting smoking. Quitting smoking is often associated with weight gain. And for some, it can lead to enough weight gain that the person becomes obese. In the long run, however, quitting smoking is still a greater benefit to your health than continuing to smoke.
- Age. Obesity can occur at any age, even in young children. But as you age, hormonal changes and a less active lifestyle increase your risk of obesity. In addition, the amount of muscle in your body tends to decrease with age. This lower muscle mass leads to a decrease in metabolism. These changes also reduce calorie needs and can make it harder to keep off excess weight. If you don't control what you eat and consciously become more physically active as you age, you'll likely gain weight.
- Social and economic issues. Certain social and economic issues may be linked to obesity. You may not have safe areas to exercise, you may not have been taught healthy ways of cooking or you may not have money to buy healthier foods. In addition, the people you spend time with may influence your weight — you're more likely to become obese if you have obese friends or relatives.
Even if you have one or more of these risk factors, it doesn't mean that you're destined to become obese. You can counteract most risk factors through diet, physical activity and exercise, and behavior changes.
If you're obese, you're more likely to develop a number of potentially serious health problems, including:
- High triglycerides and low high-density lipoprotein (HDL) cholesterol
- Type 2 diabetes
- High blood pressure
- Heart disease
- Cancer, including cancer of the uterus, cervix, endometrium, ovaries, breast, colon, rectum, esophagus, liver, gallbladder, pancreas, kidney and prostate
- Breathing disorders, including sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts
- Gallbladder disease
- Fatty liver disease
- Gynecologic problems, such as infertility and irregular periods
- Erectile dysfunction and sexual health issues
- Skin conditions, including poor wound healing
When you're obese, your overall quality of life may be lower, too. You may not be able to do things you'd normally enjoy as easily as you'd like, such as participating in enjoyable activities. You may avoid public places. Obese people may even encounter discrimination.
Other weight-related issues that may affect your quality of life include:
- Sexual problems
- Shame and guilt
- Social isolation
- Lower work achievement
Talking to your health care provider openly and honestly about your weight concerns is one of the best things you can do for your health. If you're concerned about your weight, start by seeing your primary care doctor. In some cases, you may be referred to an obesity specialist — if one is available in your area. You may also be referred to a behavioral counselor, dietitian or nutrition specialist.
What you can do
Being an active participant in your care is important. One way to do this is by preparing for your appointment. Think about your needs and goals for treatment. Be sure to let your health care provider know about any medical conditions you have and about any prescription or over-the counter medications, vitamins or supplements that you take. If you have time before your scheduled appointment, you can help prepare for the appointment by keeping a diet diary for two weeks prior to the appointment and by recording how many steps you take in a day by using a step counter (pedometer).
You can also begin to make choices that will help you start to lose weight, including:
- Starting to make healthy changes in your diet, such as eating more fruits, vegetables and whole grains and reducing portion sizes. Focus on achievable, enjoyable changes. Eat breakfast.
- Tracking how much you're eating or drinking each day so that you get a sense of how many calories you're taking in. It's easy to underestimate how many calories you actually take in every day. Bring this information with you to your appointment.
- Beginning to increase your activity level. Try to get up and move around your home more frequently. Start gradually if you aren't in good shape or aren't used to exercising. Even a 10-minute daily walk can help. If you have any health conditions, or if you're a man over age 40 or a woman over age 50, talk to your doctor or health care provider before you start a new exercise program.
You can start feeling better and seeing improvements in your health by just introducing better eating and activity habits. The initial goal is a modest weight loss — 3 to 5 percent of your total weight. That means that if you weigh 200 pounds (91 kg) and are obese by BMI standards, you would need to lose only about 6 to 10 pounds (2.7 to 4.5 kg) for your health to begin to improve. However, the more weight you lose, the greater the benefits.
All weight-loss programs require changes in your eating habits and increased physical activity. The treatment methods that are right for you depend on your level of obesity, your overall health and your willingness to participate in your weight-loss plan. Other treatment tools include:
- Dietary changes
- Exercise and activity
- Behavior change
- Prescription weight-loss medications
- Weight-loss surgery
Reducing calories and eating healthier are vital to overcoming obesity. Although you may lose weight quickly at first, slow and steady weight loss over the long term is considered the safest way to lose weight and the best way to keep it off permanently.
Avoid drastic and unrealistic diet changes, such as crash diets, because they're unlikely to help you keep excess weight off for the long term. There is no best weight-loss diet. Choose one that includes healthy foods that you feel will work for you. Dietary changes to treat obesity include:
- A reduced-calorie diet. The key to weight loss is reducing how many calories you take in. You and your health care providers can review your typical eating and drinking habits to see how many calories you normally consume and where you can cut back. You and your doctor can decide how many calories you need to take in each day to lose weight, but a typical amount is 1,200 to 1,500 calories for women and 1,500 to 1,800 for men.
- Feeling full on less. The concept of energy density can help you satisfy your hunger with fewer calories. All foods have a certain number of calories within a given amount (volume). Some foods — such as desserts, candies, fats and processed foods — are high in energy density. This means that a small volume of that food has a large number of calories. In contrast, other foods, such as fruits and vegetables, have lower energy density. These foods provide a larger portion size with a fewer number of calories. By eating larger portions of foods less packed with calories, you reduce hunger pangs, take in fewer calories and feel better about your meal, which contributes to how satisfied you feel overall.
- Adopting a healthy-eating plan. To make your overall diet healthier, eat more plant-based foods, such as fruits and vegetables. Also emphasize lean sources of protein — such as beans, lentils and soy — and lean meats. If you like fish, try to include fish twice a week. Limit salt and added sugar. Stick with low-fat dairy products.
- Restricting certain foods. Certain diets limit the amount of a particular food group, such as high-carbohydrate or full-fat foods. Drinking sugar-sweetened beverages is a sure way to consume more calories than you intended, and limiting these drinks or eliminating them altogether is a good place to start cutting calories.
- Meal replacements. These plans suggest that you replace one or two meals with their products — such as low-calorie shakes or meal bars — and eat healthy snacks and a healthy, balanced third meal that's low in fat and calories. In the short term, this type of diet can help you lose weight. Keep in mind that these diets likely won't teach you how to change your overall lifestyle, though, so you may have to keep this up if you want to keep your weight off.
- Being wary of quick fixes. You may be tempted by fad diets that promise fast and easy weight loss. The reality, however, is that there are no magic foods or quick fixes. Fad diets may help in the short term, but the long-term results don't appear to be any better than other diets. Similarly, you may lose weight on a crash diet, but you're likely to regain it when you stop the diet. To lose weight — and keep it off — you have to adopt healthy-eating habits that you can maintain over time.
Increased physical activity or exercise also is an essential part of obesity treatment. Most people who are able to maintain their weight loss for more than a year get regular exercise, even simply walking.
To boost your activity level:
- Exercise. People who are overweight or obese need to get at least 150 minutes a week of moderate-intensity physical activity to prevent further weight gain or to maintain the loss of a modest amount of weight. To achieve more significant weight loss, you may need to exercise 300 or more minutes a week. You probably will need to gradually increase the amount you exercise as your endurance and fitness improve. To make your own exercise goal more doable, break it up into several sessions throughout the day, doing just 10 minutes at a time. Exercising with a partner can make this more fun and help you maintain your motivation.
- Increase your daily activity. Even though regular aerobic exercise is the most efficient way to burn calories and shed excess weight, any extra movement helps burn calories. Making simple changes throughout your day can add up to big benefits. Park farther from store entrances, rev up your household chores, garden, get up and move around periodically, and wear a pedometer to track how many steps you actually take over the course of a day.
A behavior modification program can help you make lifestyle changes and lose weight and keep it off. Steps to take include examining your current habits to find out what factors, stresses or situations may have contributed to your obesity. Everyone is different and has different obstacles to managing weight, such as a lack of time to exercise or late-night eating. Tailor your behavior changes to address your individual concerns.
Behavior modification, sometimes called behavior therapy, can include:
- Counseling. Therapy or interventions with trained mental health or other professionals can help you address emotional and behavioral issues related to eating. Therapy can help you understand why you overeat and learn healthy ways to cope with anxiety. You can also learn how to monitor your diet and activity, understand eating triggers, and cope with food cravings. Counseling may be available by telephone, email or Internet-based programs if travel is difficult. Therapy can take place on both an individual and group basis. More-intensive programs — those that include 12 to 26 sessions a year — may be more helpful in achieving your weight-loss goals.
- Support groups. You can find camaraderie and understanding in support groups where others share similar challenges with obesity. Check with local hospitals or commercial weight-loss programs for support groups in your area, such as Weight Watchers.
Losing weight requires a healthy diet and regular exercise. But in certain situations, prescription weight-loss medication may help. Keep in mind, though, that weight-loss medication is meant to be used along with diet, exercise and behavior changes, not instead of them. If you don't make these other changes in your life, medication is unlikely to work.
- Orlistat (Xenical). This medication blocks the digestion and absorption of fat in your stomach and intestines. Unabsorbed fat is eliminated in the stool. Average weight loss with orlistat is about 4 to 9 pounds (2 to 4 kilograms). Side effects associated with orlistat include oily and frequent bowel movements, bowel urgency, and gas. These side effects can be minimized as you reduce fat in your diet. Because orlistat blocks absorption of some nutrients, take a multivitamin while taking orlistat to prevent nutritional deficiencies. There is a reduced-strength version of orlistat (Alli) that's sold over-the-counter, without a prescription. Alli is not approved for children. This medication works the same as prescription-strength orlistat and is meant only to supplement — not replace — a healthy diet and regular exercise.
- Lorcaserin (Belviq). This medication works by affecting chemicals in your brain that help decrease your appetite and make you feel full, so you eat less. Your doctor will carefully monitor your weight loss while taking lorcaserin. If you don't lose about 5 percent of your total body weight within 12 weeks of taking lorcaserin, it's unlikely the drug will work for you and the medication should be stopped. Side effects of lorcaserin include headaches, dizziness and nausea. Rare but serious side effects include a chemical imbalance (serotonin syndrome), suicidal thoughts, psychiatric problems, and problems with memory or comprehension. Pregnant women shouldn't take lorcaserin.
- Phentermine-topiramate (Qsymia). This medication combines phentermine, a weight-loss drug prescribed for short-term use, with topiramate, a medication that's used to control seizures. Your doctor will monitor your weight loss while taking the drug. If you don't lose at least 5 percent of your body weight within 12 weeks of starting treatment, your doctor may suggest either stopping use of Qsymia or increasing your dose, depending on your condition. Side effects include increased heart rate, tingling of hands and feet, dry mouth, and constipation. Serious but rare side effects include suicidal thoughts, problems with memory or comprehension, sleep disorders, and changes to your vision. Pregnant women shouldn't take Qsymia.
- Phentermine (Adipex-P, Suprenza). Phentermine is a weight-loss medication approved for short-term use (three months) in adults. Using weight-loss medications short term doesn't usually lead to long-term weight loss.
You need close medical monitoring while taking a prescription weight-loss medication. Also, keep in mind that a weight-loss medication may not work for everyone, and the effects may wane over time. When you stop taking a weight-loss medication, you may regain much or all of the weight you lost.
In some cases, weight-loss surgery, also called bariatric surgery, is an option. Weight-loss surgery offers the best chance of losing the most weight, but it can pose serious risks. Weight-loss surgery limits the amount of food you're able to comfortably eat or decreases the absorption of food and calories or both.
Weight-loss surgery for obesity may be considered if you have tried other methods to lose weight that haven't worked and:
- You have extreme obesity with a body mass index (BMI) of 40 or higher
- You're committed to making the lifestyle changes that are necessary for surgery to work
Weight-loss surgery can often help you lose as much as 35 percent or more of your excess body weight. But weight-loss surgery isn't a miracle obesity cure. It doesn't guarantee that you'll lose all of your excess weight or that you'll keep it off long term. Weight-loss success after surgery depends on your commitment to making lifelong changes in your eating and exercise habits.
Common weight-loss surgeries include:
- Gastric bypass surgery. This is the favored weight-loss surgery in the United States because it has shown greater long-term weight loss and improvement of complications, such as type 2 diabetes, than gastric banding. In gastric bypass (Roux-en-Y gastric bypass), the surgeon creates a small pouch at the top of your stomach. The small intestine is then cut a short distance below the main stomach and connected to the new pouch. Food and liquid flow directly from the pouch into this part of the intestine, bypassing most of your stomach. Serious risks from the surgery include blood clots and the need for reoperation. People with higher BMIs and those who aren't able to walk 200 feet (61 meters) or who have a history of obstructive sleep apnea have a higher risk of complications.
- Laparoscopic adjustable gastric banding (LAGB). In this procedure, your stomach is separated into two pouches with an inflatable band. Pulling the band tight, like a belt, the surgeon creates a tiny channel between the two pouches. The band keeps the opening from expanding and is generally designed to stay in place permanently. LAGB is popular because it is less invasive and generally causes slow, steady weight loss, and the band can be adjusted if needed. However, as with other procedures, this won't work without changes in your behavior. Results are usually not as good as with other procedures. Infection, blood clots and the need for another operation are possible complications associated with this surgery.
- Gastric sleeve. In this procedure, part of the stomach is removed, creating a smaller reservoir for food. There are ongoing studies evaluating this procedure.
Unfortunately, it's common to regain weight no matter what obesity treatment methods you try. But that doesn't mean your weight-loss efforts are futile.
One of the best ways to prevent regaining the weight you've lost is getting regular physical activity. Aim for 200 to 300 minutes a week. Keep track of your physical activity if it helps you stay motivated and on course. You may always have to remain vigilant about your weight. Combining a healthier diet and more activity in a practical and sustainable manner is the best way to lose weight and keep it off for the long term. If you take weight-loss medications, you'll probably regain weight when you stop taking them. You might even regain weight after weight-loss surgery if you continue to overeat or eat foods laden with fat and calories.
Take your weight loss and weight maintenance one day at a time and surround yourself with supportive resources to help ensure your success. Find a healthier way of living that you can stick with for the long term.
Your effort to overcome obesity is more likely to be successful if you follow strategies at home in addition to your formal treatment plan. These can include:
- Learning about your condition. Education about obesity can help you learn more about why you became obese and what you can do about it. You may feel more empowered to take control and stick to your treatment plan. Read reputable self-help books.
- Setting realistic goals. When you have to lose a significant amount of weight, you may set goals that are unrealistic, such as trying to lose too much too fast. Don't set yourself up for failure. Set daily or weekly goals for exercise and weight loss. Make small changes in your diet instead of attempting drastic changes that you're not likely to stick with for the long haul.
- Sticking to your treatment plan. Changing a lifestyle you may have lived with for many years can be difficult. Be honest with your doctor, therapist or other health care providers if you find your activity or eating goals slipping. You can work together to come up with new ideas or new approaches.
- Enlisting support. Get your family and friends on board with your weight-loss goals. Surround yourself with people who will support you and help you, not sabotage your efforts. Make sure they understand how important weight loss is to your health. You might also want to join a weight-loss support group.
- Identifying and avoiding food triggers. Distract yourself from your desire to eat with something positive, such as calling a friend. Practice saying no to unhealthy foods and big portions. Eat when you're actually hungry — not simply when the clock says it's time to eat.
- Keeping a record. Keep a food and activity log. This record can help you remain accountable for your eating and exercise habits. You can discover behavior that may be holding you back and, conversely, what works well for you. You can also use your log to track other important health parameters such as blood pressure and cholesterol levels and overall fitness.
- Taking your medications as directed. If you take weight-loss medications or medications to treat obesity-related conditions, such as high blood pressure or diabetes, take them exactly as prescribed.
Numerous dietary supplements that promise to help you shed weight quickly are available. The effectiveness, particularly the long-term effectiveness, and safety of these products are often questionable.
Herbal remedies, vitamins and minerals, all considered dietary supplements by the Food and Drug Administration, don't have the same rigorous testing and labeling process as prescription medications. Yet some of these substances, including products labeled as "natural," have drug-like effects that can be dangerous. Even some vitamins and minerals can cause problems when taken in excessive amounts. Ingredients may not be standard, and they can cause unpredictable and harmful side effects. Dietary supplements can also cause dangerous interactions with prescription medications you take.
Whether you're at risk of becoming obese, currently overweight or at a healthy weight, you can take steps to prevent unhealthy weight gain and related health problems. Not surprisingly, the steps to prevent weight gain are the same as the steps to lose weight: daily exercise, a healthy diet, and a long-term commitment to watch what you eat and drink.
- Exercise regularly. You need to get 150 to 300 minutes of moderate-intensity activity a week to prevent weight gain. Moderately intense physical activities include fast walking and swimming.
- Eat healthy meals and snacks. Focus on low-calorie, nutrient-dense foods, such as fruits, vegetables and whole grains. Avoid saturated fat and limit sweets and alcohol. You can still enjoy small amounts of high-fat, high-calorie foods as an infrequent treat. Just be sure to choose foods that promote a healthy weight and good health most of the time.
- Know and avoid the food traps that cause you to eat. Identify situations that trigger out-of-control eating. Try keeping a journal and write down what you eat, how much you eat, when you eat, how you're feeling and how hungry you are. After a while, you should see patterns emerge. You can plan ahead and develop strategies for handling these types of situations and stay in control of your eating behaviors.
- Monitor your weight regularly. People who weigh themselves at least once a week are more successful in keeping off excess pounds. Monitoring your weight can tell you whether your efforts are working and can help you detect small weight gains before they become big problems.
- Be consistent. Sticking to your healthy-weight plan during the week, on the weekends, and amidst vacation and holidays as much as possible increases your chances of long-term success.